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This study revisited the taxonomy and diversity of brown macroalgae within the Scytosiphonaceae family in French Polynesia, which had previously been recognized as encompassing only six species. Using the chloroplast and mitochondrial genes rbcL, psbA, and cox3 as molecular markers in conjunction with morpho‐anatomical observations, we unveiled the presence of 11 species spanning six genera: Chnoospora minima, Colpomenia claytoniae, Co. sinuosa [groups IIIa and IIIb], Hydroclathrus rapanuii, H. tenuis, H. tilesii, Manzaea minuta, Pseudochnoospora implexa, Rosenvingea australis, and the newly described species R. polynesiensis sp. nov. and R. tahitiensis sp. nov. This encompasses the recognition of two previously unreported genera in this region: Manzaea and Pseudochnoospora. Sequences were successfully acquired for four taxa that had been documented previously, while the absence of sequences for H. clathratus and H. tumulis in French Polynesia raises queries about their presence in this region. With these additions, the total species count now stands at 13 (including H. clathratus and H. tumulis), one being an endemic species. The molecular‐assisted alpha taxonomic approach used here allowed for a critical revision of the Scytosiphonaceae species checklist for French Polynesia. The diversity revealed in this region accounts for a substantial 20% of the family's global diversity. Additionally, our study presents an updated species‐level phylogeny for the Scytosiphonaceae. [ABSTRACT FROM AUTHOR]

A new genus, Rostrupomyces is established to accommodate Xerocomus sisongkhramensis based on multiple protein-coding genes (atp6, cox3, tef1, and rpb2) analyses of a wide taxon sampling of Boletaceae. In our phylogeny, the new genus was sister to Rubinosporus in subfamily Xerocomoideae, phylogenetically distant from Xerocomus, which was highly supported as sister to Phylloporus in the same subfamily Xerocomoideae. Rostrupomyces is different from other genera in Boletaceae by the following combination of characters: rugulose to subrugulose pileus surface, white pores when young becoming pale yellow in age, subscabrous stipe surface scattered with granulose squamules, white basal mycelium, unchanging color in any parts, yellowish brown spore print, and broadly ellipsoid to ellipsoid, smooth basidiospores. In addition, Hemileccinum inferius, also from subfamily Xerocomoideae, is newly described. Detailed descriptions and illustrations of the new genus and new species are presented. [ABSTRACT FROM AUTHOR]

Haemosporidian parasites that infect birds (Apicomplexa: Haemosporida) are blood parasites that require an invertebrate host (vector) and a vertebrate host for their lifecycle and cause malaria-like diseases. This group of parasites has provided valuable insights into host specificity, virulence, and parasite dispersal. Additionally, they have played a significant role in reshaping our understanding of the evolutionary history of apicomplexans. In order to accurately identify species and to address phylogenetic questions such as the timing of the haemosporidian radiation, the use of a sufficiently large genetic data set is crucial. However, acquiring this genetic data poses significant challenges. In this research, a sensitive nested PCR assay was developed. This assay allows for the easy amplification of complete mitochondrial genomes of haemosporidian parasites in birds, even during the chronic stage of infection. The effectiveness of this new nested PCR assay was evaluated using blood and tissue samples of birds with verified single parasite infections from previous studies. The approach involves amplifying four overlapping fragments of the mitochondrial genome and requires DNA extracts from single-infected samples. This method successfully amplified the complete mitochondrial genomes of 24 distinct haemosporidian parasite lineages found in various bird species. This data is invaluable for conducting phylogenetic analyses and accurately defining species. Furthermore, this study proposes the existence of at least 15 new haemosporidian parasite species based on the genetic information obtained. Data regarding pGRW04, previously categorized as Plasmodium relictum like pSGS1 and pGRW11, indicates that the pGRW04 lineage is actually a separate, hidden Plasmodium species. [ABSTRACT FROM AUTHOR]

Muscle growth and injury-induced regeneration are controlled by skeletal muscle satellite cells (MuSCs) through myogenesis in postnatal animals. Meanwhile, myogenesis is accompanied by mitochondrial function and enzyme activity. Nevertheless, the underlying molecular mechanisms involving non-coding RNAs including circular RNAs (circRNAs) and microRNAs (miRNAs) remain largely unsolved. Here, we explored the myogenic roles of miR-145-3p and MYBL1 on muscle development and mitochondrial mass. We noticed that overexpression of miR-145-3p inhibited MuSCs proliferation and reduced the number of viable cells. Meanwhile, deficiency of miR-145-3p caused by LNAantimiR-145-3p or an inhibitor retarded the differentiation of MuSCs. miR-145-3p altered the mitochondrial mass in MuSCs. Moreover, miR-145-3p targeted and negatively regulated the expression of CDR1as and MYBL1. The knockdown of the MYBL1 using ASO-2′MOE modification simulated the inhibitory function of miR-145-3p on cell proliferation. Additionally, MYBL1 mediated the regulation of miR-145-3p on Vexin, VCPIP1, COX1, COX2, and Pax7. These imply that CDR1as/miR-145-3p/MYBL1/COX1, COX2, VCPIP1/Vexin expression at least partly results in a reduction in mitochondrial mass and MuSCs proliferation. These novel findings confirm the importance of mitochondrial mass during myogenesis and the boosting of muscle/meat development in mammals. [ABSTRACT FROM AUTHOR]

SUMMARY: Colpomenia borea sp. nov. is described from Hokkaido, Japan and Magadan, Far East Russia based on morphological observations and molecular analyses using mitochondrial cox3 and chloroplast rbcL genes. This new species is distinguished from other Colpomenia by its small globular to ovoidal thallus up to 5 cm in diameter, and thin thallus membrane composed of a cortex of one to two‐cell layers and a colorless medulla of up to three layers. This species is epiphytic on the brown alga Stephanocystis in areas protected against waves. The life history in culture of C. borea was investigated and the observed life history pattern was similar to those reported in C. peregrina and C. sinuosa. Our phylogenetic analyses supported that C. borea is a distinct species, yet it is more related to C. peregrina than C. sinuosa. [ABSTRACT FROM AUTHOR]

Acute kidney injury (AKI) affects 47% of adult surgical critical care patients (ASCCPs). AKI is induced through a common oxidative stress pathway resulting in mitochondrial and tubular cell injury with increased urinary mitochondrial DNA (UmtDNA) excretion. UmtDNA is an emerging and readily sampled novel biomarker for varied surgical critical care cohorts. This review aimed to determine the clinical use of UmtDNA genes (ND1 and COX3) in AKI in ASCCPs. PubMed, MEDLINE and Web of Science databases were searched. Eligibility criteria were based on the patient/problem, intervention, comparison and outcome framework. Methodological quality of studies was assessed with the Newcastle‐Ottawa Quality Assessment Scale. WebPlot Digitizer version 4.4 was used to extract UmtDNA data from graphs and UmtDNA ratios were statistically analysed with PRISM version 9.1.0 (GraphPad Software). Six human studies (n = 391) with three translational murine models (n = 112) satisfied inclusion criteria. One sample t test suggested significantly high UmtDNA‐ND1 ratios in progressive/severe AKI (or delayed renal transplant graft function) to no AKI (or immediate renal transplant graft function) and increased UmtDNA‐COX3 ratios approached significance. Sensitivities and specificities for UmtDNA ranged from 68% to 85% and 52% to 83.6%, respectively, comparable with new biomarkers, neutrophil gelatinase‐associated lipocalin and kidney injury molecule‐1. Weak correlation was observed with serum creatinine. These findings were complemented in translational murine AKI experiments with significantly elevated ND1 and COX3. From bench to clinical practice, UmtDNA appears to be a promising novel biomarker of progressive/severe AKI (or delayed graft function). Large prospective, multi‐centre studies reporting standardised UmtDNA findings should clarify use of UmtDNA in ASCCP‐AKI management. [ABSTRACT FROM AUTHOR]

Colpomenia sinuosa is a cosmopolitan brown macroalgal species complex and hence a great candidate for evolutionary studies in the marine environment. Since 2009, three major C. sinuosa phylogenetic lineages, subdivided into eight subgroups, have been identified based on cox3 DNA sequences from worldwide collections. However, worldwide sampling remains limited and spotty. To date molecular data from Brazilian C. sinuosa populations have been limited to 10 specimens collected in a single locality. Nonetheless, C. sinuosa populations occur along the entire ~8,000 km Brazilian coast. Consequently, knowledge on population genetic diversity and spatial genetic structuring along most of the Brazilian coastline is nonexistent. To fulfill this gap in knowledge, we performed a phylogeographic analysis of C. sinuosa populations in Brazil. The highly variable cox3 marker was sequenced for 148 individuals collected in 12 localities in Brazil. Results identified two genetically distinct population groups (north vs. south) separated at 20.5° S latitude. Genetic diversity in northern populations is 14.6 and 15.5 times greater than southern populations in terms of haplotype and nucleotide diversity, respectively. Among northern populations, the Bahia state holds the largest genetic diversity. The southern populations had lower genetic diversity and no internal genetic sub‐structure suggesting past bottlenecks followed by recent colonization from northern haplotypes. Our results do not indicate recent introductions of foreign haplotypes in Brazil and reinforce the crucial importance of historical and extant allopatric, parapatric, and sympatric processes driving marine macroalgal evolution in the Southwestern Atlantic Ocean. [ABSTRACT FROM AUTHOR]

A new species Lobophora tsengii is described from Bach Long Vy (Bailongwei) Island, Haiphong Province, Vietnam. The plants inhabit the subtidal zone and have predominantly erect fan-shaped thalli that attach to the substrate by a basal holdfast. The thallus is commonly composed of a single layer of large medullary cells with four layers of cortical cells on either side of the medulla. The newly collected specimens from the island are morphologically similar to those from Hainan Island, China, but differ from the New Caledonian ones in having thicker thallus. In molecular phylogenetic analyses based on concatenated rbcL and cox3 sequences, the specimens from the island were 100% identical to those from Hainan Island, China, and they formed a clade separating from other Lobophora species. Additionally, based on analyses of numerous cox3 sequences, our specimens were also distinguished from the closely related taxa occurring in New Caledonia, Kenya, and West Australia. Combining the morphological and molecular analyses, we conclude that our specimens represent a new species of Lobophora, which is apparently endemic to the Beibu Gulf (Gulf of Tonkin) and adjacent waters. [ABSTRACT FROM AUTHOR]

The taxonomic status and species diversity of the brown algal genus Padina (Dictyotales, Phaeophyceae) was assessed based on DNA sequences and the morpho‐anatomy of specimens collected worldwide, especially from tropical and subtropical western Pacific regions. Phylogenetic analyses using chloroplast rbcL and mitochondrial cox3 gene sequences demonstrated four distinct clades for newly collected samples with high bootstrap support. Each species clade possesses a suite of morphological features that are not shared by any known species of Padina. These are P. imbricata sp. nov., Padina lutea sp. nov., P. moffittianoides sp. nov., and P. nitida sp. nov. The occurrence of these and other species of Padina clearly points to an elevated diversity of the genus in tropical/subtropical waters of the western Pacific. Phylogenetic analyses provided new insights into biogeographic characteristics of the genus, with many species in the Pacific Ocean showing shared/overlapping distributions, whereas species from the Mediterranean/Atlantic and/or the Indian Ocean tend to be confined to particular regions. Consideration has also been given to the evolutionary time frame of the genus Padina based on molecular time trees: a time tree of the concatenated data set (rbcL + cox3) revealed the estimated divergence time in the mid‐Cretaceous, whereas those of cox3 and rbcL showed older estimates pointing to the periods of mid‐Jurassic and Early Cretaceous, respectively. [ABSTRACT FROM AUTHOR]

Distributed in tropical and warm‐temperate waters worldwide, Lobophora species are found across the Greater Caribbean (i.e., Caribbean sensu stricto, Gulf of Mexico, Florida, the Bahamas, and Bermuda). We presently discuss the diversity, ecology, biogeography, and evolution of the Greater Caribbean Lobophora species based on previous studies and an extensive number of samples collected across the eastern, southern, and to a lesser extent western Caribbean. A total of 18 Lobophora species are now documented from the Greater Caribbean, of which five are newly described (L. agardhii sp. nov., L. dickiei sp. nov., L. lamourouxii sp. nov., L. richardii sp. nov., and L. setchellii sp. nov.). Within the Greater Caribbean, the eastern Caribbean and the Central Province are the most diverse ecoregion and province (16 spp.), respectively. Observed distribution patterns indicate that Lobophora species from the Greater Caribbean have climate affinities (i.e., warm‐temperate vs. tropical affinities). In total, 11 Lobophora species exclusively occur in the Greater Caribbean; six are present in the western Atlantic; two in the Indo‐Pacific; and one in the eastern Pacific. Biogeographic analyses support that no speciation occurred across the Isthmus of Panama, and that the Greater Caribbean acted as a recipient region for species from the Indo‐Pacific and as a region of diversification as well as a donor region to the North‐eastern Atlantic. The Greater Caribbean is not an evolutionary dead end for Lobophora, but instead generates and exports diversity. Present results illustrate how sampling based on DNA identification is reshaping biogeographic patterns, as we know them. [ABSTRACT FROM AUTHOR]

The brown alga Lobophora (Dictyotales, Phaeophyceae) is an important macroalga in the North‐eastern Atlantic archipelagos (i.e., Macaronesia). Notably in the Canaries it can dominate benthic assemblages. While the genus has been the subject of several ecological studies in the Canaries, no study has yet been conducted to assess species‐level diversity of Lobophora in Macaronesia. We reassessed the diversity of Lobophora in Macaronesia, reporting the presence of seven species (L. caboverdeana sp. nov., L. canariensis, L. dagamae sp. nov., L. delicata, L. dispersa, L. littlerorum, and L. schneideri). Lobophora spp. from Macaronesia are morphologically and ecologically distinguishable. In the Canaries, L. schneideri dominates the photophilic assemblages from the intertidal to 20‐30 m depth. Lobophora dagamae sp. nov. grows in less illuminated shallow habitats, and replaces L. schneideri from 30 to ~80 m. Lobophora canariensis also has a wide vertical distribution, from the intertidal to deep waters, while L. delicata, L. dispersa and L. littlerorum grow in shallow waters. The dominance of species with an upright habit versus prostrate or crustose species may be mediated by the pressure of herbivores. Four species have an amphi‐Atlantic distribution: L. littlerorum, L. canariensis, L. delicata, and L. schneideri. Lobophora schneideri and L. delicata are furthermore distributed in the Mediterranean Sea. By sampling a pivotal region in the Atlantic, this study significantly improves our knowledge of Lobophora biogeography in the Atlantic Ocean. Macaronesia constitutes a species–poor region for Lobophora where no diversification events occurred, and a region of overlap between the Greater Caribbean and the Indo‐Pacific. [ABSTRACT FROM AUTHOR]

SUMMARY: Sampling in the framework of the research program called 'La Planète Revisitée' in Kavieng and Madang (Papua New Guinea) brought thus far unknown diversity of the brown algal genus Lobophora to the surface. DNA‐assisted alpha taxonomy allowed identifying the presence of 16 species Lobophora from these two localities, which only share four species in common. Ten species are newly described, including four, which are only known to the Bismarck Sea. A more exhaustive sampling across the Bismarck Sea, and more largely across the Coral Triangle, will very likely unveil an even greater diversity. The present study underscores the fragmentary nature of our knowledge of macroalgal diversity in this region. [ABSTRACT FROM AUTHOR]

Erythrophylloporus is a lamellate genus in the family Boletaceae that has been recently described from China based on E. cinnabarinus, the only known species. Typical characters of Erythrophylloporus are reddish-orange to yellowish-red basidiomata, including lamellae, bright yellow basal mycelium and smooth, broadly ellipsoid, ellipsoid to nearly ovoid basidiospores. During our survey on diversity of Boletaceae in Thailand, several yellowish-orange to reddish- or brownish-orange lamellate boletes were collected. Based on both morphological evidence and molecular analyses of a four-gene dataset (atp6, tef1, rpb2 and cox3), they were recognised as belonging in Erythrophylloporus and different from the already known species. Two new species, E. paucicarpus and E. suthepensis are therefore introduced from Thailand with detailed descriptions and illustrations. Moreover, two previously described Phylloporus species, P. aurantiacus and P. fagicola, were also revised and recombined in Erythrophylloporus. A key to all known Erythrophylloporus species is provided. [ABSTRACT FROM AUTHOR]

We introduce a new genus, Cacaoporus, characterised by chocolate brown to dark brown basidiomata and hymenophore, tubes not separable from the pileus context, white to off-white basal mycelium, reddening when bruised, amygdaliform to ovoid spores and dark brown spore deposit. Phylogenetic analyses of a four-gene dataset (atp6, tef1, rpb2 and cox3) with a wide selection of Boletaceae showed that the new genus is monophyletic and sister to the genera Cupreoboletus and Cyanoboletus in the Pulveroboletus group. Two new species in the genus, C. pallidicarneus and C. tenebrosus are described from northern Thailand. Full descriptions and illustrations of the new genus and species are presented. The phylogeny also confirmed the reciprocal monophyly of Neoboletus and Sutorius, which further support the separation of these two genera. [ABSTRACT FROM AUTHOR]

Lobophora is a common tropical to temperate genus of brown algae found in a plethora of habitats including shallow and deep-water coral reefs, rocky shores, mangroves, seagrass beds, and rhodoliths beds. Recent molecular studies have revealed that Lobophora species diversity has been severely underestimated. Current estimates of the species numbers range from100 to 140 species with a suggested center of diversity in the Central Indo-Pacific. This study used three molecular markers (cox3, rbcL, psbA), different single-marker species delimitation methods (GMYC, ABGD, PTP), and morphological evidence to evaluate Lobophora species diversity in theWestern Atlantic and the Eastern Pacific oceans. Cox3 provided the greatest number of primary species hypotheses(PSH), followed by rbcL and then psbA. GMYC species delimitation analysis was the most conservative across all three markers, followed by PTP, and then ABGD. The most informative diagnostic morphological characters were thallus thickness and number of cell layers in both the medulla and the dorsal/ventral cortices. Following a consensus approach, 14 distinct Lobophora species were identified in the Western Atlantic and five in the Eastern Pacific. Eight new species from these two oceans were herein described: L. adpressa sp. nov., L. cocoensis sp. nov., L. colombiana sp. nov., L. crispata sp. nov., L. delicata sp. nov., L. dispersa sp. nov., L. panamensis sp. nov., and L. tortugensis sp. nov. This study showed that the best approach to confidently identify Lobophora species is to analyze DNA sequences (preferably cox3 and rbcL) followed by comparative morphological and geographical assessment. [ABSTRACT FROM AUTHOR]

SUMMARY: Conspecific populations with different life‐cycle seasonality, particularly of their reproductive season, have been reported for many seaweed species. However, the number of genetic analyses of such seasonal populations is limited. Herein, based on the mitochondrial cytochrome oxidase subunit 3 gene (cox3) haplotype, we evaluated the genetic diversity of winter (January–March) and spring (April–June) fertile populations of the brown alga Sargassum horneri in Sado Island, Japan. Obviously, dominant cox3 haplotypes were different between seasons (even at a single site), and the NST values indicated the presence of a strong genetic differentiation between the two seasonal populations. AMOVA analyses confirmed that most of the genetic diversity was between seasons rather than between regions. Herein, the possibility of allochronic isolation is discussed. Considering the phylogeny of the mitochondrial cox3 DNA sequence, autumn or winter seasonal populations such as those in this investigation have evolved independently at least twice in the species. The present study shows that a shift in breeding season could be expected to conserve the genetic diversity of S. horneri in a certain region. [ABSTRACT FROM AUTHOR]

Two species of the brown algal genus Rosenvingea are reported from south-west (SW) Australia, including the widely distributed R. orientalis and the new species R. australis Huisman, G.H. Boo et S.M. Boo, sp. nov. Molecular phylogenies of mitochondrial cox3 and plastid psaA unequivocally align the SW Australian R. orientalis with specimens from Vietnam and the species is morphologically consistent throughout its Australian range. Australian specimens of the new species R. australis join with a specimen from New Caledonia and these resolve as a sister species to R. intricata, with levels of pairwise divergence (4.2-4.9% in cox3 and 3.9-4.0% in psaA) comparable to those between other scytosiphonacean species. The new species can be distinguished morphologically by its branch dimensions and the arrangement and size of plurangia, but further studies including molecular analyses of a full range of species and possible morphological variants are needed. [ABSTRACT FROM AUTHOR]

Abstract: Aim: Hainan Island, southern China, is characterized by rich diversity and endemism of marine organisms, yet the underpinning mechanisms and processes contributing to speciation and diversification are poorly understood. Here, the brown alga Sargassum polycystum is used as a model to identify putative marine glacial refugia and explore biogeographical patterns driven by climate change in the late Pleistocene ice ages. Location: South‐East Asia. Methods: Mitochondrial cox1 and cox3 and nuclear internal transcribed spacer‐2 (ITS2) were obtained from 310, 325 and 313 individuals of S. polycystum (23 localities), respectively. Phylogenetic trees (maximum likelihood and Bayesian inference) and haplotype/ribotype networks were constructed to elucidate phylogeographical patterns. Analysis of molecular variance (AMOVA), neutrality tests (Tajima's D and Fu & Li's D*), current (θπ) and historical (θw) genetic diversities and extended Bayesian skyline plots (EBSP) were used to estimate historical demography. Results: The populations from the south‐west of Hainan Island harboured much higher genetic diversity and unique endemism in comparison with other populations in the distribution range. Sargassum polycystum experienced relatively long‐term stable population size followed by a continued period of demographic expansion in the late Pleistocene. Main conclusions: Our phylogeographical evidence revealed the existence of a previously unidentified marine refugium specific to S. polycystum in the south‐west of Hainan Island, China (the Central Depression of the Yinggehai Basin), along with a possible secondary refugium around the Bali Island, Indonesia. These biogeographical findings provide important insights regarding speciation, adaptation and evolution of marine organisms in South‐East Asia and the conservation of unique biodiversity under climate change. [ABSTRACT FROM AUTHOR]

Among the distinctive members of the brown algal family Scytosiphonaceae is the genus Hydroclathrus, which is primarily distinguished by its clathrate (net-like) appearance. Hydroclathrus, despite being seasonal and species poor, is a conspicuous floristic component in many tropical to warm temperate coasts. However, compared with other closely related genera, such as Colpomenia and Rosenvingea, Hydroclathrus remains poorly known; its taxonomy remains problematic, as information on the molecular phylogenetic relationships of the species is still scarce. We attempted to bridge these gaps by describing the diversity and molecular phylogeny of Hydroclathrus based on morphological and genetic (mitochondrial cox1 and cox3 and plastidial psaA and rbcL genes) data. We recognised four Hydroclathrus species: H. clathratus, H. stephanosorus, H. tenuis and H. minutus sp. nov., which is morphologically cryptic to H. tenuis. A new clathrate genus, Tronoella ryukyuana gen. & sp. nov., is also erected based on specimens from southern Japan. Tronoella is primarily distinguished from Hydroclathrus in possessing (1) highly convoluted thalli with branches that are sometimes slightly twisted and/or interadhesive; (2) siphonous protrusions that grow randomly and in various directions, later on becoming perforated branches with revolute margins; and (3) plurangia that are firmly coherent and massive. Our results highlight the need to re-evaluate the identity of the species reported as H. clathratus and H. tenuis and underscore the need to re-examine the taxonomy and systematics of the family Scytosiphonaceae. [ABSTRACT FROM AUTHOR]

Two new bistratose species of the brown algal genus Padina, P. ogasawaraensis sp. nov. and P. reniformis, sp. nov., were discovered from Ogasawara and Okinawa Islands, and Kagoshima, Japan, respectively, and characterised based on a combination of morphological and molecular analyses. Padina ogasawaraensis is characterised by a semicircular or circular yellowish-brown thallus with light to heavy calcification except at the hairlines and presence of hairlines on both surfaces in an alternating sequence. These can be seen as a broad-depressed line with a remnant of a thin red hairline at its center on the inferior surface and as a narrow or sometimes rudimentary line on the superior surface. Indusiate reproductive sori are located distally adjacent to the hairlines on the inferior surface, partially to deeply embedded in the epidermis layer. Padina reniformis is characterised by a semicircular or kidney-shaped greenish brown thallus with light to moderate calcification on both surfaces of the thallus. Hairlines are present only on one (inferior) surface and are narrow, not depressed. Indusiate tetrasporangial sori are arranged in two to three rows between the hairlines on the inferior surface and situated on the thallus surface. Molecular phylogenetic analyses using rbcL and cox3 DNA sequences placed them in distantly related clades. Padina ogasawaraensis showed a sister relationship to P. calcarea; whereas, P. reniformis was sister to P. fasciata. [ABSTRACT FROM AUTHOR]

To clarify the significance of genetic resources in the marine crop Undaria pinnatifida, we investigated whether morphological features of two cultivars were genetically different from each other based on combined studies of morphological and molecular analyses. The two cultivars were produced, respectively, by self-fertilization between male and female gametophytes, which were each developed from a single zoospore from two morphologically different sporophytes cultivated in the eastern Seto Inland Sea, Japan. Their sporophytes, each with the same genotype, were cultivated in an Undaria farm under the same environmental conditions and were periodically collected for morphometric comparisons. The results of this experimental cultivation demonstrate that various morphological features, such as the blade, stipe, and sporophyll shapes, and developmental processes of the divided blade and sporophyll, clearly differed between the two cultivars. Although the two cultivars showed identical haplotypes in both of the mitochondrial cox3 gene and the tatC- tLeu region, they exhibited different genotypes at the microsatellite loci. These results indicate that morphological and developmental differences were genetically controlled, in addition to phenotypic plasticity due to changes in environmental conditions. It is therefore necessary for the marine crop breeding program to collect more mature sporophytes of cultivated and wild U. pinnatifida from various regions and to establish more female and male gametophyte strains each developed from a single zoospore. The origin of U. pinnatifida cultivated in the eastern Seto Inland Sea, famous for Japanese Undaria cultivation, is also discussed. [ABSTRACT FROM AUTHOR]

Parasitic nematodes of Oesophagostomum spp., commonly known as 'nodular worms' are one of the most widely distributed and prevalent emerging zoonotic nematodes. However, little is known about the prevalence and gene characteristics of those parasites in Tibetan pigs. Therefore, a study was carried out to investigate the prevalence, isolation and identification of Oesophagostomum spp from Tibetan pigs by genetic markers of nad1, cox3 and ITS1 for the first time. The results revealed that the infection rate of O. dentatum and O. quadrispinulatum by genetic markers of nad1 was 81.13%; 35 (66.04%); the O. dentatum and O. quadrispinulatum by genetic markers cox3 was 66.04%, and O. dentatum and O. stephanostomum by genetic markers ITS1 was found to be 77.36%. Interestingly, the O. stephanostomum specie was identified and isolated from 90.48% stomach and 69.23% colon samples by genetic markers of ITS1. The present study, for the first time has described the presence and genetic characterization of Oesophagostomun spp of O. dentatum, O. quadrispinulatum and especially O. stephanostomum in Tibetan pigs from the high and remote Tibetan plateau. A public concern should be raised in terms of economical losses and severe public health problem. [ABSTRACT FROM AUTHOR]

Lobophora rosacea C.W. Vieira, Payri et De Clerck is reported from the South China Sea for the first time. Our specimens are very similar to L. rosacea recently described from New Caledonia, not only in morphology but also in rbcL and cox3 gene sequences. The fan-shaped thallus grows erectly, attaching to the substrate by a basal holdfast. The thallus is composed of a single layer of large medullary cells and three to four layers of cortical cells on both sides of the medulla. Mature sporophytes are detected, with sporangium sori scattered on both surfaces of the thallus. [ABSTRACT FROM AUTHOR]

Molecular-assisted alpha taxonomy has provided novel ways of exploring biodiversity, and is of great help in taxa where morphology alone is not sufficient to ensure accurate species recognition or delimit species boundaries. Here, we use this approach to assess the taxonomy of Padina Adanson (Dictyotales, Phaeophyceae), a common brown algal genus in Mexican waters. Numerous individuals of Padina from Pacific and Atlantic tropical coasts were analysed using sequences of psbA, cytochrome c oxidase subunit I, and cox3 to determine evolutionary significant units or putative species. Then, cox3 sequences of some individuals of each group were analysed with a large number of sequences available in Genbank using the generalized mixed Yule coalescent and Poisson tree processes models for species delimitation. Each sample was identified using the original and the most common descriptions in the region. Last, the results were evaluated looking for correlations between the molecular and morphological data. We concluded that at least 12 Padina species occurred in Mexican waters, 10 from samples here revised and 2 inferred from Genbank sequences. The study not only revealed the existence of well-identified species, but also the existence of cryptic and polymorphic species, confirming the importance of reassessing type material for proper delimitation and nomenclature. Finally, the evidence supported the independent status of Padina ramonribae Avila-Ortiz, Pedroche & Díaz-Martínez, which is validated here. [ABSTRACT FROM AUTHOR]

Global climate change is expected to alter the polar bioregions faster than any other marine environment. This study assesses the biodiversity of seaweeds and associated eukaryotic pathogens of an established study site in northern Baffin Island (72° N), providing a baseline inventory for future work assessing impacts of the currently ongoing changes in the Arctic marine environment. A total of 33 Phaeophyceae, 24 Rhodophyceae, 2 Chlorophyceae, 12 Ulvophyceae, 1 Trebouxiophyceae, and 1 Dinophyceae are reported, based on collections of an expedition to the area in 2009, complemented by unpublished records of Robert T. Wilce and the first-ever photographic documentation of the phytobenthos of the American Arctic. Molecular barcoding of isolates raised from incubated substratum samples revealed the presence of 20 species of brown seaweeds, including gametophytes of kelp and of a previously unsequenced Desmarestia closely related to D. viridis, two species of Pylaiella, the kelp endophyte Laminariocolax aecidioides and 11 previously unsequenced species of the Ectocarpales, highlighting the necessity to include molecular techniques for fully unraveling cryptic algal diversity. This study also includes the first records of Eurychasma dicksonii, a eukaryotic pathogen affecting seaweeds, from the American Arctic. Overall, this study provides both the most accurate inventory of seaweed diversity of the northern Baffin Island region to date and can be used as an important basis to understand diversity changes with climate change. [ABSTRACT FROM AUTHOR]

Using mitochondrial cox3 and chloroplast rbcL-rbcS DNA sequences, molecular phylogeny of Papenfussiella species that were collected from various localities in Japan revealed considerable species diversity in the genus. Although only P. kuromo has been recognized in Japan, in the molecular phylogeny Japanese Papenfussiella formed four distinct clades (clades 1, 2, 3 and 4) with high statistical supports. Specimens of clade 1 corresponded to P. kuromo because the morphology agreed well with the reported descriptions of the species, and the DNA sequences agreed with the lectotype specimen. Clade 2 comprised the syntype specimens of P. kuromo f. densa Inagaki, having distinctively narrow and wellbranched thalli. Papenfussiella kuromo f. gracilis was not distinguishable from P. kuromo f. densa in morphology, nor in the DNA sequences. Specimens of clade 3 were collected from Shikoku and were similar to P. kuromo in gross morphology but were anatomically different from P. kuromo in having a subcortical layer. Specimens comprising clade 4 were collected from Akkeshi, eastern Hokkaido, and resembled P. callitricha in gross morphology but were distinct in having longer assimilatory filaments and isodiametric medullary cells. In summary, we propose the establishment of two new species, P. shikokuensis sp. nov. for clade 3 and P. iemasae sp. nov. for clade 4, and to reappraise P. kuromo f. densa and f. gracilis as an independent species, P. densa slat. nov. In addition, preliminary genetic study of the Southern Hemisphere Papenfussiella species suggested the occurrence of several cryptic species in the genus. [ABSTRACT FROM AUTHOR]

In depth genetic comparisons of populations of C utleria multifida ( Tilopteridales, Phaeophyceae) collected from Europe, the northwestern Pacific Ocean, Australia and New Zealand using the DNA sequences of four gene regions (the mitochondrial cox2 and cox3 genes, the intergeneric spacer region adjacent to cox3, and the open reading frame) suggested that the northwestern European and Japanese populations were considerably greater in terms of their genetic divergence than Mediterranean, Australian or New Zealand populations. The haplotypes of the populations in northwestern European (distribution range including the type locality, seven haplotypes) and Japanese populations (seven haplotypes) were unique except for one shared haplotype. There were weak but positive correlations between the geographical distance and the genetic divergence among northwestern European and Japanese populations. Moreover, both female and male gametophytes occurred in eight of the nine Japanese localities, suggesting Japanese populations showed normal sexual heteromorphic life history of the species. In light of these results, it appears that Japanese populations were native to the area despite earlier hypothesis. In contrast, Australian and New Zealand populations were composed of only one haplotype that is very close to those found in northwestern Europe and Japan, suggesting a recent introduction history from Europe (or from northeastern Asia via Europe) by ship transport to Australia and New Zealand. The Mediterranean populations included two haplotypes identical to those found in northwestern Europe and Japan, and it is suggestive of transoceanic introductions of some populations between Mediterranean and Japanese coasts. [ABSTRACT FROM AUTHOR]

In the western Atlantic Ocean, the brown algal genusLobophorais currently represented by a single species,L. variegata, with a type locality designated by Lamouroux as ‘Antilles’. In this study, we used molecular-assisted alpha taxonomy (MAAT) to assess species diversity ofLobophorain Bermuda, the Florida Keys, St. Croix and Guadeloupe (Lesser Antilles). Usingcox1 andcox3 sequences as barcode markers, five species ofLobophora, four of them novel, were delineated, all previously having been identified in the area asL. variegata. Our morphological and habitat studies, made possible by abundant sampling, have revealed unique characters for each of these western Atlantic species, including distinct cellular arrangements, as well as different depth ranges for certain species. Observations made from Lamouroux’s holotype ofDictyota variegata(=Lobophora variegata) allowed us to assess the anatomy of this species, which enabled us to easily align this early taxon to one of our genetic species from the western Atlantic. As the type was unavailable for genetic analysis, we selected a recent St. Croix (Virgin Is., Antilles) specimen as the epitype to support it with molecular sequence data. [ABSTRACT FROM PUBLISHER]

Scytosiphon lomentaria (Scytosiphonaceae, Ectocarpales) is believed to include some cryptic species, particularly in the Pacific. We attempted to delimit these species in Japan using mitochondrial cox1 and cox3 and nuclear ITS2 and the second intron of the centrin gene (cetn-int2). Fifty-three cox1+cox3 mitotypes, 26 ITS2 ribotypes and 45 cetn-int2 haplotypes were found in 107 samples collected from 33 localities in Japan. Based on phylogenetic analyses, similar sequence types were grouped into ten mitogroups, eight ribogroups and six cetn-int2 haplogroups (sequence-type groups). From the molecular trees and combinations of the mito-, ribo- and haplogroups, three cryptic species were apparent (Groups I-III). Group I, widely distributed on Pacific coasts, was highly supported by all molecular trees, whereas Groups II (North Pacific) and III (Northwestern Pacific and Australasia) were more closely related to each other. However, sequence-type-group combinations that would be characteristic of hybrids between Groups II and III were not detected, suggesting no gene flow between the two Groups. Further investigations of an additional 127 sympatrically growing plants supported the absence of gene flow between Groups II and III. Four samples did not belong to any of the Groups I-III and possibly represent additional species. [ABSTRACT FROM AUTHOR]

The common brown alga Scytosiphon lomentaria (Scytosiphonaceae) has generally been regarded as a species complex. In the Pacific, molecular data have shown that it includes more than one species; the diversity in other oceans, however, has not been examined. In the present study, the genetic diversity of S. lomentaria was investigated in 57 samples from the north-east Atlantic (mainly from Ireland) and twofrom the Mediterranean, which were compared with seven samples from Japan. Phylogenetic analyses based on the mitochondrial cytochrome oxidase subunit 3 gene (cox3) and nuclear ribosomal internal transcribed spacers (ITS1 and 2) revealed four separate monophyletic groups. Clades A1 and A2 consisted of the samples from the north-east Atlantic; the Mediterranean samples also belonged to Al. The affiliation of four samples was incongruent between cox3 and ITS trees, suggesting directional mitochondrial introgression from A2 to A l . Clades PI and P2 contained nine samples from the north-east Atlantic, i.e. three Irish, all Norwegian and Icelandic samples, as well as all Pacific samples; in these clades, the cox3 and ITS data were congruent. This is the first documented record of Pacific lineages of Scytosiphon in the north-east Atlantic. Our results indicate that at least four species are passing under the name S. lomentaria in the north-east Atlantic and the Mediterranean. [ABSTRACT FROM AUTHOR]

The use of molecular markers to evaluate species delineation in the genusSargasssumis of critical importance given the large variability of morphological traits among and within taxa. To date, most molecular studies of this group have focused on the central Indo-Pacific region, even though the genus is also well represented in the Atlantic Ocean. In the present study, we re-assessed the diversity and taxonomy ofSargassumand the monospecific genusCladophyllumfrom Caribbean Colombia (especially from the Santa Marta-Tayrona National Natural Park) and extended to the western tropical Atlantic towards a comprehensive revision of the genus in this basin based on morphological and molecular analyses (ITS-2,rbcLS,cox3 andmtsp) on new and existing collections from the region. Sequences obtained from the genusCladophyllumrevealed its nesting insideSargassumsubgenusSargassumas a close relative ofS. pteropleuron, a broadly distributed species in the Caribbean. Analysis of molecular divergence in this newly identified clade demonstrated a similar range of variation as that present in existing sections leading to the description of a new section,Sargassumsect.Cladophyllum(Bula-Meyer) Camacho, Mattio & Diaz-Pulido, sect. nov., that includes the two sister species mentioned above. Based on these results, we also mergedCladophyllumwithinSargassumand renamed its unique speciesS. schnetteri(Bula-Meyer) Camacho, Mattio & Diaz-Pulido, comb. nov. The remainingSargassumspp. included in the analyses clustered in a polytomy within the worldwide-distributedS. sectionSargassum, thus providing no support for the other eight morphological species currently recognized in the Caribbean Colombia and other western tropical Atlantic areas. Based on the morphological analysis we further described a new species,S. giganteumCamacho & Diaz-Pulido sp. nov., endemic from TNNP. Detailed morphological descriptions and illustrations, as well as an identification key, are provided for all studied taxa. [ABSTRACT FROM AUTHOR]

The taxonomic distinctiveness and distribution of the brown alga Colpomenia phaeodactyla are debatable. The type locality of this species is Puerto Penasco, Mexico, and its distribution includes northeast Asia. We analyzed two gene sequences of specimens of so-called C. phaeodactyla from Korea, Japan and Mexico, in combination with morphological observations of the specimens. Analyses of 71 coxi and 23 rbcL sequences resulted in similar trees in which specimens under the name C. phaeodactyla consisted of two distinct clades. One clade comprised samples from Korea and Japan, and the other clade, from the Gulf of California, was identical to C. durvillei. Additional observations of the morphology and anatomy of the specimens agreed with the molecular data. On the basis of these results, we describe the new species C. wynnei for plants from Korea and Japan. Colpomenia wynnei was distinguished by finger-like sacs with adventitious branchlets when mature and was much contorted, the height of ascocysts being shorter than plurilocular sporangia. Both cox3 and rbcL sequence data strongly supported the monophyly of C. wynnei, C. bullosa and C. durvillei, all being characterized by having elongate thalli. Based on both cox3 and rbcL data sets, we herein propose to synonymise C. phaeodactyla with C. durvillei. [ABSTRACT FROM AUTHOR]

The Indo-Pacific Ocean is a biodiversity hotspot for marine organisms. In this area, most of the research has focused on marine animals, such as reef fish, molluscs and other associated coral fauna, but very little has been done on macroalgae. The Thai-Malay Peninsula is an important north–south barrier in this area, which faces two different oceans – the Indian Ocean and the Pacific Ocean. This study aims to investigate genetic distribution patterns ofPadina boryanaThivy around the Thai-Malay Peninsula, where it is common. Three DNA marker regions, the mitochondrion-encoded cytochromecoxidase subunit 3 gene (cox3); the plastidrbcL, and the nuclear internal transcribed spacer 2 (ITS2) were used to evaluate genetic diversity and the relationships within and between populations. Samples were collected from both the Andaman Sea and Gulf of Thailand sides of the peninsula. Parsimony networks and maximum likelihood and Bayesian analyses showed clearly that there are two separatedP. boryanalineages, one restricted to the Gulf of Thailand and the other to the Andaman Sea and other areas of the Indo-Pacific. The effect of different ocean currents along the Andaman Sea and Gulf of Thailand may have shaped these populations ofP. boryana.This phylogeographic separation, based on persistent currents in the area, may affect other marine organisms along the Thai peninsula. [ABSTRACT FROM AUTHOR]

Sargassum polycystum C. Agardh is one of the most abundant marine brown algae and is distributed widely in warm and temperate waters, particularly in the Indo-west Pacific region and Australia. Although its commercial potential and ecological and evolutionary importance are recognized, many pivotal aspects of its biology remain unexplored. Current knowledge of the historical biogeographical affinities and patterns is limited, but some data are available about its genetics, the genetic variation among populations, and spatial patterns. This study aimed to analyze the genetic population structure and distribution patterns of S. polycystum populations in 13 different locations from Indonesia to Japan using the mitochondrial gene cox3. The seven haplotypes of cox3 identified in this study indicated a low level of genetic diversity. Homogeneity of this haplotype was observed particularly in the Gulf of Thailand, Cambodia, and Japan, whereas higher haplotype diversity was found in Phuket (Thailand), Bali (Indonesia), and Singapore. Those data suggest that S. polycystum is likely to have expanded from the south of Indonesia and the west of the Malay Peninsula towards the northeast of the region. Geological studies showed that Sundaland, now corresponding to the Gulf of Thailand, was submerged due to sea level rises after the last glacial period. Therefore, the decrease in the genetic diversity of S . polycystum populations is interpreted here as a population expansion after the rise in sea levels. [ABSTRACT FROM AUTHOR]

Molecular phylogenetic analyses based on plastid-encoded rbcL and mitochondrial cox3 gene sequences, in combination with morphological observations, revealed the existence of the following four bistratose Padina species previously unreported from Australian coasts: Padina calcarea Ni-Ni-Win, S.G.A. Draisma, W.F. Prudhomme van Reine & H. Kawai, characterised by its bright yelloworange inferior thallus surface and chalky white, heavily calcified superior surface, and the presence of hairlines only on the inferior surface; P. macrophylla Ni-Ni-Win, M. Uchimura & H. Kawai, characterised by a moderately calcified thallus with broad, depressed hairlines on the inferior surface and narrow, not depressed hairlines on the superior surface, those hairlines that are largely spaced on each surface; P. moffittiana I.A. Abbott & Huisman, characterised by lightly calcified thalli with narrow, slightly depressed hairlines that are distributed in alternate sequence between the two surfaces at unequal distances, and broad reproductive sori in one or two rows in the fertile zone; and P. okinawaensis Ni-Ni-Win, S. Arai, M. Uchimura & H. Kawai, characterised by heavily calcified thalli, except at the hairlines, which form an alternation of uncalcified furrows and calcified glabrous zones on the inferior surface. With the addition of these four species, 13 Padina species are known from Australia. [ABSTRACT FROM AUTHOR]

The Sargassuni subgenera Bactrophycus and Arthrophycus were considered to be geographically restricted to the northern and southern hemispheres, respectively. Phylogenetic analyses of 19 Sargassum subgenus Bacirophycus species and eight Sargassuni subgenus Art hrophycus species, based on a concatenated dataset of the loci ITS-2, cox3 and the rbcL-S spacer, showed that they formed a single dade, with Arthrophvcus species nested within Bactrophycus section Halochloa. We merged the two subgenera as subgenus Bactrophycus and transferred "Arthrophycus" species to Sargassum section Halochloa. The genus now includes only the two subgenera, Sargassum and Bactrophycus. and both were found at temperate and subtropical latitudes; only subgenus Sargassum occurred at low latitudes near the equator, whereas subgenus Bactrophycus had an antitropical, disjunct distribution. [ABSTRACT FROM AUTHOR]

Mauritius and Reunion are part of the Mascarene Islands situated in the southwestern Indian Ocean, c. 800 km east of Madagascar. A total of 44 different Sargassum species and subspecific taxa was listed in the literature for these islands. This was a remarkable number for such isolated and small islands, and was more than have been recorded from Madagascar or other East African countries. The first aim of our study was to revise these species lists using newly collected specimens to provide a reliable and illustrated tool for the identification of the Mauritian and Reunion Sargassum. On the basis of morphological and molecular analyses, a total of six taxa was identified as S. cymosum f. borbonicum, S. obovatum, S. pfeifferae (reinstated), S. polycystum, S. portierianum and S. robillardii (stat. nov.). A seventh taxon, S. scopula, was identified from a herbarium collection but not re-collected. As a result of our taxonomic revision, we concluded that most of the species listed in the literature for both Mauritius and Reunion were misidentifications or synonyms, and we proposed three new taxonomic synonyms. The biogeography of the six Sargassum taxa was further investigated using local and regional hydrodynamic dispersal models. Results underlined the isolated position of the Mascarene Islands with (1) unlikely import of Sargassum in present-day conditions, (2) likely dispersal/exchanges within the archipelago and (3) a two-pronged export of Sargassum to the east coast of Madagascar and the Seychelles with a major stream northwestward and a weaker stream south westward. These oceanic conditions had probably shaped the Sargassum diversity of the Mascarene Islands and in particular explained the endemicity of 5. cymosum f. borbonicum and restricted distribution of S. obovatum, S. pfeifferae, S. robillardii and S. scopula [ABSTRACT FROM AUTHOR]

The COX3 gene is located in the mitochondrial genome and encodes the cytochrome c oxidase subunit III of the respiratory chain in yeast. In addition to an 810-bases-coding region, the COX3 mRNA has a 613-bases 5′ untranslated region (UTR) and an approximately 2.2-kb 3′UTR. Studies on the expression of COX3 have shown that the COX3 5′UTR sequences are involved in the translation initiation of the COX3 mRNA. However, the function of the COX3 3′UTR in gene expression is unknown. In this study, we report molecular characteristics of a mitochondrial cox3 mutant, M9-3, with alterations in the COX3 3′UTR. We found that COX3 mRNA levels in M9-3 are comparable to those in its wild-type parent strain. But we found that levels of subunit III, the COX3 gene product, are reduced in M9-3 relative to its wild-type. Together, these observations suggest a possible role for the COX3 3′UTR sequences in the subunit III synthesis. [ABSTRACT FROM AUTHOR]

Recent DNA sequencing studies have demonstrated that many widespread species consist of species complexes with high genetic diversity. The brown alga Colpomenia sinuosa is a suitable candidate for studies into cryptic diversity because of its cosmopolitan distribution in the world's oceans. To examine the genetic diversity within the species and the relationships of the genetic lineages to current distribution, we analyzed a total of 134 cox3 sequences from C. sinuosa specimens collected in 19 countries; we also examined 16 rbcL from a subset of the specimens for comparative purposes. Phylogenetic trees and haplotype analyses of cox3 and rbcL revealed high cryptic diversity comprising three genealogical groups within C. sinuosa. Two groups overlapped in the Indo-Pacific and Atlantic regions, one was confined to the tropics, while the remaining group was localized in the Red Sea and western Mediterranean Sea. Thus, the current distribution of C. sinuosa may well result from a mixture of modern anthropogenic introductions and ancient relicts. [ABSTRACT FROM AUTHOR]

Two new species of Padina - 1. Padina sulcata sp. nov. and 2. P. calcarea sp. nov. - from Malaysia, Indonesia and Palau were described based on morphological and molecular phylogenetic observations. Padina sulcata was a three-layered species characterised by a covering of thick fibrous hairs from the base to the middle of the inferior surface (away from the in-rolled margin) of the thallus; conspicuous equally spaced hairlines that alternated between both frond surfaces; and broad, indusiate oogonial and tetrasporangial sori that occupied nearly the entire fertile zones, and the fertile zones were separated by sterile zones of equal width. Padina calcarea was a two-layered species characterised by a bright yellow inferior surface and a thick calcification on the superior surface (facing to the in-rolled margin), which imparted a strikingly whitish color; inconspicuous hairlines were confined to the inferior surface; and indusiate tetrasporangial sori were just above the hairlines and were found only on the inferior surface. Molecular phylogenetic analyses used chloroplast rbcL and mitochondrial cox3 gene sequences and revealed that the two new species each form strongly supported clades that were genetically distant. Padina calcarea formed an isolated clade that made an early divergence; whereas, P. sulcata showed a sister relationship to P. ryukyuana, indicating a more recent divergence. Padina calcarea was very similar to the Hawaiian P. melemele in gross appearance, particularly in the bright orange to yellow color of the inferior thallus surface and the heavy calcification on the superior surface. However, they were distinguished mainly by the position and arrangement of reproductive sori that were found on the inferior surface and located just above the hairlines in P. calcarea but that were found on the superior surface between the hairlines of the opposite surface in P. melemele. Molecular phylogenetic analyses did not reflect the morphological similarity of the two species because they occupied two distantly related clades. [ABSTRACT FROM AUTHOR]

A taxonomic revision of Lobophora based on molecular phylogenetic analyses of rbcL and cox3 gene sequences as well as anatomical observations was carried out, mostly based on specimens collected from eastern Asia and southeastern Australia. In the molecular phylogenetic analyses, nine major clades supported by high bootstrap values were recognized. In combination with evaluation of morphological characters, four clades were concluded to be new species. The Australian species L. australis sp. nov. possessed erect thalli with sporangial son scattered on the ventral surface and had a closer phylogenetic relationship with another Australian species, L. nigrescens, but it was distinguished from the latter in having fewer layers of cortical cells and smaller sporangia. The Asian species L. crassa sp. nov., L. pachyventera sp. nov. and L. asiatica sp. nov. possessed decumbent thalli with sporangia scattered on the dorsal surface. Among the three prostrate species, L. crassa had a considerably thicker thallus with four to five cortical layers, L. asiatica had a thinner thallus with two cortical layers, and L. pachyventera differed from another two species by its three-layered ventral cortex and well-developed anchoring rhizoids. [ABSTRACT FROM AUTHOR]

The taxonomic distinctiveness and distribution of the brown alga Colpomenia durvillei are debatable; the species was first described from central Chile. We analyzed mitochondrial cox3 and plastid rbcL sequences from specimens collected in central Chile and Sonora, Mexico, in combination with morphological observations of specimens collected in Chile, Peru, and Mexico. Compared with other elongate species of the genus, C. durvillei is distinguished by erect, elongate thalli arising from a wide colpomenioid base, up to eight layers of cortical and medullary cells, and plurilocular sporangia with many layers (up to 18 locules). In all phylogenetic analyses of cox3 and rbcL sequences, all elongate species of the genus formed a clade, in which C. durvillei was consistently distinct from congeners. Colpomenia bullosa was closely related to C. durvillei in our cox3 analyses, and the clade containing these two species was closely related to Colpomenia phaeodactyla. This is the first report to confirm C. durvillei by molecular data and also the first report on the occurrence of the species in Sonora, Mexico. It had previously been misidentified as a variant of C. phaeodactyla on the Pacific coast of South America, and the name C. durvillei was misapplied to C. bullosa in New Zealand. [ABSTRACT FROM AUTHOR]

A study of the genus Padina in the Mediterranean Sea, based on detailed morphological and molecular analyses using chloroplast rbcL and mitochondrial cox3 gene sequences, as well as RuBisCO spacer and partial rbcS sequences, revealed the presence of two new species, P. ditristromatica Ni-Ni-Win & H. Kawai and P. pavonicoides Ni-Ni-Win & H. Kawai. They are two to three-layered and three-layered species, respectively. Padina ditristromatica is characterized by a thallus composed of two cell layers from the marginal portion to the inrolled margin and a mixture of two and three layers in the other portions; heavy calcification on both surfaces of the thallus except for the hair lines; alternating hair lines that are spaced at unequal distances between the upper and lower surfaces; and broad indusiate oogonial and tetrasporangial sori forming broken lines or patches arranged in a concentric row, which are distally close to the hair lines and half immersed in the epidermis layer only on the lower surface. Padina pavonicoides is characterized by a thallus composed of three cell layers from the base to the marginal portion and two layers at the inrolled margin; alternating hair lines that are spaced at equal distances between the upper and lower surfaces; and indusiate oogonial and tetrasporangial sori forming patches located distal to the hair lines only on the lower surface. All molecular phylogenetic analyses indicated that the new species are closely related to P. pavonica, a common species in the Mediterranean Sea. However, the cox3 region could not be amplified for P. ditristromatica. Therefore, the RuBisCO spacer and partial rbcS were analysed for the Mediterranean specimens in order to confirm their identity as well as their closest relationships. The combined rbcL, RuBisCO spacer and partial rbcS data also support their genetic separation and show that P. pavonica is more closely related to P. pavonicoides than P. ditristromatica, as in other molecular analyses. [ABSTRACT FROM AUTHOR]

Agarum is a perennial kelp genus that has a broad distribution from the northwest Pacific to the northwest Atlantic Ocean. In order to address questions regarding phylogenetic relationships and present-day distribution patterns of species within this genus, we analyzed the nuclear ITS2, mitochondrial cox1 and cox3, and plastid RuBisCO spacer from a subset of 130 samples of the genus plus Thalassiophyllum and Costaria. All analyses of the individual markers and the ITS2 + cox1 + cox3 dataset consistently produced a clade of Agarum that included Thalassiophyllum. The clade consisted of two well-resolved subelades: one composed of A. fimbriatum and A. oharaense, and the other of A. clathratum, A. turneri, A. yakishiriense, and T clathrus (the type of the generic name Thalassiophyllum). On the basis of these results, we treat Thalassiophyllum as a synonym of Agarum, reinstating the combination A. clathrus made by Grey Ile in 1830. Despite its wide distribution from Japan through Alaska to the east coast of North America, A. clathratum had low genetic diversity, suggesting a relatively recent long-distance dispersal of the species. The low degree of substitutions Fetween A. clathratum and A. yakishiriense suggests their recent divergence from a common ancestor, and we recognize the latter as a subspecies of the former. Because type material of A. clathratum has not been found, we designate as neotype a specimen collected in Kamchatka, one of two syntype localities cited by Gmelin for Fucus agarum. [ABSTRACT FROM AUTHOR]

Colpomenia, a small genus with 11 species of globular to bullate form, occurs in temperate to tropical waters worldwide. Because morphology is highly diverse, the species-level taxonomy requires re-evaluation. We analyzed the mitochondrial cox3 gene from 50 samples of the genus. A new species, Colpomenia claytonii sp. nov., is described based on samples collected from Korea, Japan, Hong Kong, Australia, New Zealand, South Africa, and the USA and compared with similar congeners. Compared to others, the new species is larger, and has a more irregular thallus often with a deeply infolded surface. It is usually epilithic in tide pools and in the lower intertidal and subtidal zones. In all phylogenetic analyses of cox3 sequences, C. claytonii was consistently distinct from congeners. Colpomenia expansa is closely related to C. claytonii, and the clade containing these two species is closely related to C. peregrina. A total of 14 cox3 haplotypes was found in C. claytonii, indicating high haplotype diversity and a recent dispersal pattern. The present study shows that C. claytonii is a widely distributed species across the Pacific Ocean to South Africa; it was previously misidentified as a variant of C. peregrina. [ABSTRACT FROM AUTHOR]

The COX3 gene encodes a core subunit of mitochondrial cytochrome c oxidase (complex IV) whereas the COX17 gene encodes a chaperone delivering copper to the enzyme. Mutants of these two genes were isolated by RNA interference in the microalga Chlamydomonas. The COX3 mRNA was completely lacking in the cox3-RNAi mutant and no activity and assembly of complex IV were detected. The cox17-RNAi mutant presented a reduced level of COX17 mRNA, a reduced activity of the cytochrome c oxidase but no modification of its amount. The cox3-RNAi mutant had only 40% of the wild-type rate of dark respiration which was cyanide-insensitive. The mutant presented a 60% decrease of HO production in the dark compared to wild type, which probably accounts for a reduced electron leakage by respiratory complexes III and IV. In contrast, the cox17-RNAi mutant showed no modification of respiration and of HO production in the dark but a two to threefold increase of HO in the light compared to wild type and the cox3-RNAi mutant. The cox17-RNAi mutant was more sensitive to cadmium than the wild-type and cox3-RNAi strains. This suggested that besides its role in complex IV assembly, Cox17 could have additional functions in the cell such as metal detoxification or Reactive Oxygen Species protection or signaling. Concerning Cox3, its role in Chlamydomonas complex IV is similar to that of other eukaryotes although this subunit is encoded in the nuclear genome in the alga contrary to the situation found in all other organisms. [ABSTRACT FROM AUTHOR]

Cutleria cylindrica Okamura was described from Japan in 1902 and has been reported only from northwestern Asia until its relatively recent discovery in California, USA, and Baja California, Mexico. To clarify the genetic relationships within and among the disjunct populations, we carried out a molecular phylogenetic study, as well as the examination of sex ratio and the life-history patterns, of populations in Japan, Korea, and California. Based on the DNA sequences of mitochondrial genes cox2, cox3, the open reading frame (ORF) region, and the spacer between cox3 and ORF, a total of 23 haplotypes were detected in the 85 individuals from 20 localities in Japan, Korea, and California. All localities in Japan and Korea included multiple haplotypes, but only a single haplotype was found in California. There was a positive relationship between distance and genetic divergence in Japan and Korea. The single haplotype found in California was the same as one occurring in Japan (Aomori Pref. and Fukuoka Pref.) and Korea (Daedaepo, Pusan). Both male and female gametophytes were distributed in most northeastern Asian populations. Only female gametophytes, developing parthenogenetically from female gametes, were found in California and Aomori Pref., Japan. On the basis of these results, we conclude that the disjunct population of C. cylindrica in California originated from a relatively recent introduction from Japan and shares its origin with the parthenogenetic population in the Tsugaru Strait. [ABSTRACT FROM AUTHOR]

Molecular phylogenetic analyses of Padina species collected from the western Pacific Ocean using rbcL and mitochondrial cox3 genes revealed the occurrence of four genetically distinctive clades of unknown Padina species: clade A (=Padina okinawaensis sp. nov.) from Ryukyu Islands (Japan), Hawaii, Indonesia and Thailand, clade B (=Padina undulata sp. nov.), clade C (=Padina terricolor sp. nov.) and clade D (=Padina fasciata sp. nov.) from Ryukyu Islands (Japan). Morphologically, these new taxa are all bistratose species, and different from any known species in the following morphological features: P. okinawaensis sp. nov., reniform or circular thallus of entire margin with inconspicuous hair lines on the superior surface of the thallus, and reproductive organs (oogonia and tetrasporangia) in small groups or discontinuous sori under thin flakes of calcium on the inferior surface; P. undulata sp. nov., circular or semicircular thallus with undulate margin, conspicuous hair lines on both surfaces of the thallus, oogonial and tetrasporangial sori in continuous or discontinuous lines covered with a persistent indusium, and cylindrical oogonia; P. terricolor sp. nov., grayish brown on the inferior surface of the thallus, and oogonial and tetrasporangial sori in continuous lines covered with a persistent indusium; P. fasciata sp. nov., broad white stripes on both surfaces of the thallus due to unique calcification, and oogonial and tetrasporangial sori in continuous lines, which are entirely embedded in a gelatinous layer, on the inferior surface of the thallus. In addition, the independence of Padina japonica from Padina sanctae-crucis is suggested on the basis of molecular and morphological evidence. [ABSTRACT FROM AUTHOR]

Systematic relationships between representative Leathesia species (i.e. Leathesia difformis, L. japonica, L. pulvinata and L. sphaerocephala) and related taxa (i.e. Corynophlaea cystophorae and Kurogiella saxicola) within the Ectocarpales s.l. were re-examined based on the combined DNA sequences of plastid rbcL and mitochondrial cox3 genes. Resultant molecular phylogenetic trees showed polyphyly of Leathesia species; Leathesia japonica, L. sphaerocephala and L. pulvinata (members of Leathesia section Primariae), which share solid thallus construction, grouped together with Botrytella spp. rather than L. difformis (generitype; section Leathesia), which was close to Elachista tenuis and Cladosiphon okamuranus. Leathesia japonica clustered with Botrytella species rather than L. sphaerocephala and L. pulvinata. A close phylogenetic relationship between L. japonica and Botrytella species was supported by the occurrence of the characteristic free, sympodially branching filaments forming clustered plurilocular zoidangia in L. japonica, resembling Botrytella in culture and field-collected material. Based on these molecular phylogenetic analyses and morphological characteristics, we propose the establishment of Phaeophysema gen. nov. to accommodate L. sphaerocephala and L. pulvinata, and Vimineoleathesia gen. nov. to accommodate L. japonica. [ABSTRACT FROM AUTHOR]

Sargassum C. Agardh (1820) is a taxonomically difficult genus distributed worldwide and reported as the most species-rich genus of the Fucales. It is especially abundant in the Pacific where decreasing species richness is reported to occur from west to east. New Caledonia has been recognized as one of the hotspots of Sargassum diversity; however, species lists available for this region are old and incomplete and have not yet been updated with regard to the latest taxonomic revisions published. This study aimed at revising Sargassum diversity in New Caledonia and to assess its geographic affinities with neighboring Pacific regions. We used combined morphological and DNA analyses on new collections and examined numerous type specimens. Although 45 taxa have been listed in the literature, most of them have been either transferred to synonymy since or misidentified, and in this study, only 12 taxa were recognized as occurring in New Caledonia. They belong to the subgenus Sargassum sect. Binderianae (Grunow) Mattio et Payri (2), sect. Ilicifoliae (J. Agardh) Mattio et Payri (2), sect. Polycystae Mattio et Payri. (1), sect. Sargassum (4), sect. Zygocarpicae (J. Agardh) Setch. (2), and subgenus Phyllotrichia (Aresh.) J. Agardh (1). New Caledonian Sargassum flora appeared as the second richest in the region after the Pacific coast of Australia, with which it has shown high similarity, and shared species with all neighboring regions. One species, S. turbinarioides Grunow, is considered as endemic to New Caledonia. The low genetic diversity detected among several polymorphic species belonging to sect. Sargassum is also discussed. [ABSTRACT FROM AUTHOR]