Search

Five matrine-type alkaloids (1‒5) including two new compounds (1 and 3) and a new natural product (2) were isolated from the roots of Sophora tonkinesis. Their structures were identified by extensive spectroscopic analysis (UV, IR, HRESIMS and NMR). The absolute configurations of 2 and 3 were determined by X-ray diffraction. Compounds 1‒5 were evaluated their activity against inflammatory cytokines TNF-α and IL-6 levels on LPS-induced RAW 264.7 macrophages, and compound 1 showed the most significant activity, potent than that of matrine, the representative ingredient from Sophora plants.

The small-eared shrew genus Cryptotis is the third largest in the family Soricidae and occurs in North, Central, and northern South America. In Mexico and Central and South America, most species inhabit geographically isolated moist, montane habitats at middle and high elevations in a typical sky-island pattern. The 49 recognized species have been partitioned into as many as six species groups based on morphological and molecular phylogenetic studies. The relationships among these species groups are poorly resolved, and their evolutionary histories, including migration patterns and locomotor adaptations, remain unclear. Herein, we provide a new phylogeny incorporating complete mitochondrial genomes (mitogenomes) and supermatrix approach. We compared different evolutionary scenarios using approximately unbiased (AU), Kishino-Hasegawa (KH), and Shimodaira-Hasegawa (SH) statistical tests. The phylogenetic hypothesis based on mitogenomes revealed novel relationships supporting a basal position for the Cryptotis parvus-group in the genus, and a close relationship between C. gracilis and one clade of the C. thomasi-group. The former relationship is consistent with the least derived humerus morphology and northern distribution of the species. The latter relationship implies multiple migrations between Central and South America. The lack of fine resolution for the species group relationships may be due partly to the lack of taxon sampling. In contrast, multi-approach analyses suggest that the unresolved relationships may be a result of rapid diversification during the early stages of Cryptotis evolution.

The silver butter catfish (Schilbe intermedius) is widely distributed across African river systems. To date, information on its mitochondrial genetic diversity, population structure, and historical demography are not well-established. Herein, we combined newly generated mitochondrial cytochrome c oxidase (COI) subunit I gene sequences with previously published COI sequences in the global databases to reconstruct its phylogeography, population genetic structure, and historical demography. Results from the mtDNA phylogeography and species delimitation tests (Cluster algorithm – Species Identifier, Automatic Barcode Gap Discovery and Poison Tree Process model) revealed that S. intermedius comprises at least seven geographically defined matrilines. Although the overall haplotype diversity of S. intermedius was high (h = 0.90), results showed that East (Kenya) and West (Nigeria) African populations had low levels of haplotype diversity (h = ~0.40). In addition, population genetic polymorphism and historical demographics showed that S. intermedius populations in both East and West Africa underwent severe contractions as a result of biogeographic influences. The patterns of genetic diversity and population structure were consistent with adaptive responses to historical biogeographic factors and contemporary environmental variations across African river systems. This is suggestive of the influence of historical biogeographic factors and climatic conditions on population divergence of S. intermedius across African river systems. Given our discovery of previously underappreciated diversity within S. intermedius, we recommend that this species be considered for increased conservation and management.

Sugarcane mosaic virus (SCMV), Sorghum mosaic virus (SrMV), Sugarcane streak mosaic virus (SCSMV), Sugarcane yellow leaf virus (SCYLV), and Sugarcane bacilliform virus (SCBV) are the major viruses infecting sugarcane worldwide. This study proposed a multiplex reverse transcription–polymerase chain reaction (RT–PCR) assay for the simultaneous detection and identification of these sugarcane viruses. Results showed that five primer pairs amplified their respective target viruses, indicating the assay specificity. The sensitivity of the assay was similar to or 10–100-folds lower than that of singleplex RT–PCR for detecting SCMV or the four other viruses, respectively. When detecting the five viruses in field sugarcane samples, the detection results of multiplex RT–PCR were approximately identical to those of singleplex RT–PCR, thereby indicating the relative reliability of the former. The proposed multiplex RT–PCR can simultaneously detect SCMV, SrMV, SCSMV, SCYLV, and SCBV in sugarcane, making it a suitable, efficient, and practical detection method for sugarcane viruses.

Sugarcane is an important sugar and energy crop worldwide. It utilises highly efficient C4 photosynthesis and accumulates sucrose in its culms. The sucrose content in sugarcane culms is a quantitative trait controlled by multiple genes. The regulatory mechanism underlying the maximum sucrose level in sugarcane culms remains unclear. We used transcriptome sequences to identify the potential regulatory genes involved in sucrose accumulation in Saccarum officinarum L. cv. Badila. The sucrose accumulating internodes at the elongation and mature growth stage and the immature internodes with low sucrose content at the mature stage were used for RNA sequencing. The obtained differentially expressed genes (DEGs) related to sucrose accumulation were analysed. Results showed that the transcripts encoding invertase (beta-fructofuranosidase, EC: 3.2.1.26) which catalyses sucrose hydrolysis and 6-phosphofructokinase (PFK, EC: 2.7.1.11), a key glycolysis regulatory enzyme, were downregulated in the high sucrose accumulation internodes. The transcripts encoding key enzymes for ABA, gibberellin and ethylene synthesis were also downregulated during sucrose accumulation. Furthermore, regulated protein kinase, transcription factor and sugar transporter genes were also obtained. This research can clarify the molecular regulation network of sucrose accumulation in sugarcane.

Hexokinase (HXK) catalyses hexose phosphorylation and senses glucose signalling to control carbon partition in plants. In sugarcane, HXK is involved in regulating source/sink carbon balance. However, the characteristics of sugarcane HXK genes remain unclear. This study revealed that the full-length cDNA sequence of the HXK gene ShHXK8 cloned from sugarcane mature leaves contains a 1560 bp open reading frame and encodes a putative protein of 519 amino acids. Amongst HXKs from monocot and dicot subjected to phylogenetic analysis, ShHXK8 was clustered into a monocot-specific group with OsHXK7, SbHXK8 and ZmHXK1. Gene expression analysis in Saccharum spp. hybrid ROC22 plants showed that ShHXK8 was expressed in leaves and stalks and expressed highly in mature leaves and young internodes. The difference in the expression of ShHXK8 was compared in high-sugar-content (HSC) and low-sugar-content (LSC) Saccharum officinarum plants. The expression of ShHXK8 in the leaves and internodes 3–24 of HSC plants was lower than that of LSC plants. The expression of ShHXK8 in the internodes 1–2 of HSC plants was higher than that of LSC plants. ShHXK8–GFP fusion was located in the cytosol by transiently expressing the corresponding vectors in rice mesophyll protoplasts. ShHXK8 might function as a cytoplasmic hexokinase involved in hexose metabolism in sugarcane mature leaves and young internodes.

Sugarcane streak mosaic virus (SCSMV, genus Poacevirus) causes sugarcane mosaic disease and leads to considerable economic losses. However, current methods for SCSMV diagnosis are limited. In this study, a novel isothermal assay was established on the basis of reverse transcription–recombinase polymerase amplification (RT-RPA) and evaluated in terms of its ability to detect SCSMV. The established RT-RPA assay with high specificity and reliability was 100-fold more sensitive than the RT-polymerase chain reaction. The evaluation of the temperature limit revealed that the assay had a flexible reaction temperature (26–46 °C), thereby indicating that the reaction mixture can be incubated with simple heating equipment, ambient temperature, or even human body heat. Time limit assessment results revealed that SCSMV can be detected in 5 min at 38 °C and in 20 min at 26 °C, thereby suggesting that the assay was rapid for SCSMV detection. Overall, the RT-RPA assay was specific, sensitive, reliable, and rapid for SCSMV detection, with a flexible and easily reachable reaction temperature. Thus, it can be an ideal method for SCSMV detection in sugarcane.

Sugarcane yellow leaf virus (SCYLV, genus Polerovirus) is a harmful agent that causes sugarcane yellow leaf disease. Current methods for SCYLV detection present some limitations. In this study, a novel isothermal amplification assay, namely reverse transcription-recombinase polymerase amplification (RT-RPA), was developed to promote SCYLV detection for disease management. The assay was evaluated in terms of specificity, sensitivity, reliability, temperature limit, and time limit. The developed RT-RPA assay was highly specific and non-cross-reactive with Potato leafroll virus, which is a type of species in Polerovirus. This assay can also detect at least 103-fold diluted cDNA from a SCYLV-infected sugarcane leaf, and its sensitivity is tenfold lower than that of RT-polymerase chain reaction (PCR). The reliability of the proposed assay was examined by detecting field sugarcane samples via RT-RPA and RT-PCR assays. The RT-RPA assay showed the same results as those of RT-PCR assay, indicating that the former was highly reliable for SCYLV detection. Analysis of the temperature and time limits revealed a wide operating temperature range from 27 to 45 °C, which was easily reached, and a rapid assay duration of 20 min. In summary, the developed RT-RPA assay was rapid, specific, and reliable with acceptable sensitivity and easily reachable operating temperature and thus could be a promising tool for SCYLV diagnosis in sugarcane.

In this study, we sequenced the complete mitochondrial genome (mitogenome) of the Thai Red Junglefowl (RJF; Gallus gallus) using the next-generation sequencing (NGS) platform of the Ion Torrent PGM. Samples were taken from Mae Wang District, Chiang Mai Province, northern Thailand. Our data showed the complete mitogenome to be 16 785 bp in length, composed by 13 protein-coding genes, 22 tRNA genes, two rRNA genes, and one control region. The genome nucleotide composition was 30.3% A, 23.7% T, 32.5% C, and 13.5% G, resulting in a high percentage of A+T (50.4%). Phylogenetic analysis revealed that the mitogenome belonged to haplogroup X, whereas those of all domestic chickens belong to haplogroups A to G. This newly released mitogenome sequence will advance further evolutionary and population genetics study of the RJF and domestic chicken. The availability of the G. gallus mitogenome will also contribute to further conservation genetics research of a unique species, listed as 'data deficient' in Thailand.

Several previous genomic studies have focused on adaptation to high elevations, but these investigations have been largely limited to endotherms. Snakes of the genus Thermophis are endemic to the Tibetan plateau and therefore present an opportunity to study high-elevation adaptations in ectotherms. Here, we report the de novo assembly of the genome of a Tibetan hot-spring snake (Thermophis baileyi) and then compare its genome to the genomes of the other two species of Thermophis, as well as to the genomes of two related species of snakes that occur at lower elevations. We identify 308 putative genes that appear to be under positive selection in Thermophis. We also identified genes with shared amino acid replacements in the high-elevation hot-spring snakes compared with snakes and lizards that live at low elevations, including the genes for proteins involved in DNA damage repair (FEN1) and response to hypoxia (EPAS1). Functional assays of the FEN1 alleles reveal that the Thermophis allele is more stable under UV radiation than is the ancestral allele found in low-elevation lizards and snakes. Functional assays of EPAS1 alleles suggest that the Thermophis protein has lower transactivation activity than the low-elevation forms. Our analysis identifies some convergent genetic mechanisms in high-elevation adaptation between endotherms (based on studies of mammals) and ectotherms (based on our studies of Thermophis).

Aim Insects feeding on seeds and fruits represent interesting study systems, potentially able to lower the fitness of their host plants. In addition to true seed eaters, a suite of insects feed on the fleshy parts of fruits. We examined the likelihood of community convergence in whole insect assemblages attacking seeds/fruits in three tropical rainforests. Location Three ForestGEO permanent forest plots within different biogeographical regions: Barro Colorado Island (Panama), Khao Chong (Thailand) and Wanang (Papua New Guinea). Methods We surveyed 1,186 plant species and reared 1.1 ton of seeds/fruits that yielded 80,600 insects representing at least 1,678 species. We assigned seeds/fruits to predation syndromes on the basis of plant traits relevant to insects, seed/fruit appearance and mesocarp thickness. Results We observed large differences in insect faunal composition, species richness and guild structure between our three study sites. We hypothesize that the high species richness of insect feeding on seeds/fruits in Panama may result from a conjunction of low plant species richness and high availability of dry fruits. Insect assemblages were weakly influenced by seed predation syndromes, both at the local and regional scale, and the effect of host phylogeny varied also among sites. At the driest site (Panama), the probability of seeds of a plant species being attacked depended more on seed availability than on the measured seed traits of that plant species. However when seeds were attacked, plant traits shaping insect assemblages were difficult to identify and not related to seed availability. Main conclusions We observed only weak evidence of community convergence at the intercontinental scale among these assemblages. Our study suggests that seed eaters may be most commonly associated with dry fruits at relatively dry tropical sites where fleshy fruits may be less prevalent.

The DNA barcoding gene COI (cytochrome c oxidase subunit I) effectively identifies many species. Herein, we barcoded 172 individuals from 37 species belonging to nine genera in Rhacophoridae to test if the gene serves equally well to identify species of tree frogs. Phenetic neighbor joining and phylogenetic Bayesian inference were used to construct phylogenetic trees, which resolved all nine genera as monophyletic taxa except for Rhacophorus, two new matrilines for Liuixalus, and Polypedates leucomystax species complex. Intraspecific genetic distances ranged from 0.000 to 0.119 and interspecific genetic distances ranged from 0.015 to 0.334. Within Rhacophorus and Kurixalus, the intra- and interspecific genetic distances did not reveal an obvious barcode gap. Notwithstanding, we found that COI sequences unambiguously identified rhacophorid species and helped to discover likely new cryptic species via the synthesis of genealogical relationships and divergence patterns. Our results supported that COI is an effective DNA barcoding marker for Rhacophoridae.

Capture hybridization coupled with high-throughput sequencing (HTS) has become one of the most popular approaches to address some scientific problems not only for fundamental evolution but also for ecology and human disease in recent years. However, the technical problem of limited probe capture ability affects its widespread application. Here, we propose to capture hybridize long-range DNA fragments for HTS (termed LR-LCH). We provide a case of three amphibian samples to examine LR-LCH with 2 kb libraries and comparison of standard capture hybridization with 480 bp libraries. Capture sensitivity increased from an average 13.57% of standard capture hybridization to an average 19.80% of LR-LCH; capture efficiency also increased from an average 72.56% of standard capture hybridization to an average 97.71% of LR-LCH. These indicate that longer fragments in the library generally contain both relatively variable regions and relatively conservative regions. The divergent parts of target DNA are enriched along with conservative parts of DNA sequence that effectively captured during hybridization. We present a protocol that allows users to overcome the low capture sensitivity problem for high divergent regions.

Genetically modified crops which had been commercial applied extensively majorly are the insect resistance and herbicide tolerance events. In this study, the Bt insecticidal gene Cry1Ab, the glyphosate-tolerant gene EPSPS, and the selection marker gene PMI were combined into a single transferred DNA fragment and introduced into sugarcane by Agrobacterium-mediated transformation. Thirty-three resistant plantlets were obtained after selection using a PMI/mannose selection system. Thirty of these resistant plantlets were PCR positive for the three target genes. Southern blot assay revealed that the copy number of the integrated fragment in the transformed plantlets varied from 1 to 7. ELISA analysis showed that 23 of the 33 resistant plantlets expressed Cry1Ab and EPSPS protein. Five single-copy and ELISA-positive transgenic lines were tested under laboratory and field conditions to determine their resistance to insects and herbicides, and also evaluated their agronomic characteristics and industrial traits. Results showed that larvae fed with fodder mixture containing stem tissues from single-copy transgenic lines were weak and small, moreover, pupation and eclosion were delayed significantly during voluntary feeding bioassays. None of transgenic sugarcane was destroyed by cane borer while more than 30% of wild type sugarcane was destroyed by cane borer. For herbicide resistance, the transgenic plantlets grew healthy even when treated with up to 0.5% roundup while wild type plantlets would die off when treated with 0.1% roundup. Thus demonstrate that these transgenic lines showed strong insect resistance and glyphosate tolerance under both laboratory and field conditions. But in the field most of the transgenic plants were shorter and more slender than non-transformed control plants. So they presented poor agronomic characteristics and industrial traits than non-transformed control plants. Thus, a considerable number of embryogenic calli should be infected to obtain transgenic lines with potential for commercial use.

This study examines the utility of morphology and DNA barcoding in species identification of freshwater fishes from north‐central Nigeria. We compared molecular data (mitochondrial cytochrome c oxidase subunit I (COI) sequences) of 136 de novo samples from 53 morphologically identified species alongside others in GenBank and BOLD databases. Using DNA sequence similarity‐based (≥97% cutoff) identification technique, 50 (94.30%) and 24 (45.30%) species were identified to species level using GenBank and BOLD databases, respectively. Furthermore, we identified cases of taxonomic problems in 26 (49.00%) morphologically identified species. There were also four (7.10%) cases of mismatch in DNA barcoding in which our query sequence in GenBank and BOLD showed a sequence match with different species names. Using DNA barcode reference data, we also identified four unknown fish samples collected from fishermen to species level. Our Neighbor‐joining (NJ) tree analysis recovers several intraspecific species clusters with strong bootstrap support (≥95%). Analysis uncovers two well‐supported lineages within Schilbe intermedius. The Bayesian phylogenetic analyses of Nigerian S. intermedius with others from GenBank recover four lineages. Evidence of genetic structuring is consistent with geographic regions of sub‐Saharan Africa. Thus, cryptic lineage diversity may illustrate species’ adaptive responses to local environmental conditions. Finally, our study underscores the importance of incorporating morphology and DNA barcoding in species identification. Although developing a complete DNA barcode reference library for Nigerian ichthyofauna will facilitate species identification and diversity studies, taxonomic revisions of DNA sequences submitted in databases alongside voucher specimens are necessary for a reliable taxonomic and diversity inventory.

State Key Laboratory of Genetic Resources and Evolution and Yunnan Laboratory of Molecular Biology of Domestic Animals, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China; Key Laboratory of Animal Models and Human Disease Mechanisms, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China; Forensic Science Service of Yunnan Endangered Species Scientific Commission, Kunming 650223, China; Centre for Biodiversity and Conservation Biology, Royal Ontario Museum, Toronto M5S 2C6, Canada; Guizhou Academy of Testing and Analysis, Guiyang 550002, China; Laboratory for Conservation and Utilization of Bio-resource and Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, Kunming 650091, China

In this study, we sequenced the complete mitochondrial DNA genome (mitogenome) of the Zhengyang Yellow chicken (Gallus gallus domesticus) by next-generation sequencing technology. Samples were taken from Zhumadian city, Henan Province, China. The complete mitogenome was 16 785 bp in size, and had a nucleotide composition of 30.3% (A), 23.7% (T), 32.5% (C), and 13.5% (G), with a high AT content of 54.0%. The assembled mitogenome exhibited typical mitochondrial DNA (mtDNA) structure, including a non-coding control region, two rRNA genes, 13 protein-coding genes, and 22 tRNA genes. Phylogenetic analysis indicated that this mitogenome defined a novel sub-haplogroup B3 within haplogroup B. These results should provide essential information for chicken domestication and insight into the evolution of genomes.

Urbanization requires the conversion of natural land cover to cover with human-constructed elements and is considered a major threat to biodiversity. Bee populations, globally, are under threat; however, the effect of rapid urban expansion in Southeast Asia on bee diversity has not been investigated. Given the pressing issues of bee conservation and urbanization in Southeast Asia, coupled with complex factors surrounding human–bee coexistence, we investigated bee diversity and human perceptions of bees in four megacities. We sampled bees and conducted questionnaires at three different site types in each megacity: a botanical garden, central business district, and peripheral suburban areas. Overall, the mean species richness and abundance of bees were significantly higher in peripheral suburban areas than central business districts; however, there were no significant differences in the mean species richness and abundance between botanical gardens and peripheral suburban areas or botanical gardens and central business districts. Urban residents were unlikely to have seen bees but agreed that bees have a right to exist in their natural environment. Residents who did notice and interact with bees, even though being stung, were more likely to have positive opinions towards the presence of bees in cities.

During 30 years of unprecedented urbanization, plant diversity in Shenzhen, a young megacity in southern China, has increased dramatically. Although strongly associated with plant diversity, butterfly diversity generally declines with urbanization, but this has not been investigated in Shenzhen. Considering the speed of urbanization in Shenzhen and the large number of city parks, we investigated butterfly diversity in Shenzhen parks. We measured butterfly species richness in four microhabitats (groves, hedges, flowerbeds, and unmanaged areas) across 10 parks and examined the relationship with three park variables: park age, park size, and distance from the central business district. Butterflies were identified based on wing morphology and DNA barcoding. We collected 1933 butterflies belonging to 74 species from six families; 20% of the species were considered rare. Butterfly species richness showed weak negative correlations with park age and distance from the central business district, but the positive correlation with park size was statistically significant (p = 0.001). Among microhabitat types, highest species richness was recorded in unmanaged areas. Our findings are consistent with others in suggesting that to promote urban butterfly diversity it is necessary to make parks as large as possible and to set aside areas for limited management. In comparison to neighbouring cities, Shenzhen parks have high butterfly diversity.

DNA barcoding facilitates the identification of species and the estimation of biodiversity by using nucleotide sequences, usually from the mitochondrial genome. Most studies accomplish this task by using the gene encoding cytochrome oxidase subunit I (COI; Entrez COX1). Within this barcoding framework, many taxonomic initiatives exist, such as those specializing in fishes, birds, mammals, and fungi. Other efforts center on regions, such as the Arctic, or on other topics, such as health. DNA barcoding initiatives exist for all groups of vertebrates except for amphibians and nonavian reptiles. We announce the formation of Cold Code, the international initiative to DNA barcode all species of these ‘cold-blooded’ vertebrates. The project has a Steering Committee, Coordinators, and a home page. To facilitate Cold Code, the Kunming Institute of Zoology, Chinese Academy of Sciences will sequence COI for the first 10 specimens of a species at no cost to the steward of the tissues.

In order to achieve a thorough coverage of the basal lineages in the Chinese matrilineal pool, we have sequenced the mitochondrial DNA (mtDNA) control region and partial coding region segments of 6,093 mtDNAs sampled from 84 populations across China. By comparing with the available complete mtDNA sequences, 194 of those mtDNAs could not be firmly assigned into the available haplogroups. Completely sequencing 51 representatives selected from these unclassified mtDNAs identified a number of novel lineages, including five novel basal haplogroups that directly emanate from the Eurasian founder nodes (M and N). No matrilineal contribution from the archaic hominid was observed. Subsequent analyses suggested that these newly identified basal lineages likely represent the genetic relics of modern humans initially peopling East Asia instead of being the results of gene flow from the neighboring regions. The observation that most of the newly recognized mtDNA lineages have already differentiated and show the highest genetic diversity in southern China provided additional evidence in support of the Southern Route peopling hypothesis of East Asians. Specifically, the enrichment of most of the basal lineages in southern China and their rather ancient ages in Late Pleistocene further suggested that this region was likely the genetic reservoir of modern humans after they entered East Asia.

LHON is one of the most common and primary causes of acute blindness in young male adults. Over 95% of LHON cases are caused by one of the three primary mutations (m.11778G>A, m.14484T>C, and m.3460G>A). In contrast to these genetically diagnosed LHON patients, there are many patients with clinical features of LHON but without the three primary mutations, and these patients have been insufficiently analyzed. We reported 10 suspected Chinese LHON families without the three primary mutations. The overall penetrance (53.4%) in these families is significantly higher than in those families with m.11778G>A (33.3%) or m.3460G>A (25.6%). Complete mtDNA genome sequencing of the 10 families showed that they belonged to different haplogroups and all identified variants (excluding m.12332A>G in mt-tRNA(Leu)) were previously reported. Eight of 12 private non-synonymous variants in the probands are located in the MT-ND1 and MT-ND5 genes, which is substantially higher than that of individuals from general Chinese populations. Comparison of the private variants in the 10 families and in 10 randomly selected mtDNAs from general Chinese populations using resampling simulation strategy further confirmed this pattern. Our results suggest that the MT-ND1 and MT-ND5 genes are mutational hotspots for Chinese families with suspected LHON lacking the common primary mutations. Variants m.3736G>A (p.V144I) in family Le1235 and m.10680G>A (p.A71T) in Le1107 can be the pathogenic mutations for LHON.

A new gomphid species, named as Gomphidictinus tongi sp. nov. (Holotype male, Mt. Diaoluoshan, altitude 930m a.s.l., Lingshui County, Hainan Province, China) is described here. It is regarded as the third species of Gomphidictinus based on the presence of the basal spine on median segment of the penis organ. Gomphidia interruptistria Zha, Zhang & Zheng, 2005 is regarded as a junior synonym of Gomphidictinus perakensis (Laidlaw, 1902), which is recorded from Yunnan, China.

Mitochondrial DNA (mtDNA) is widely used in various genetic studies of domesticated animals. Many applications require comprehensive knowledge about the phylogeny of mtDNA variants. Herein, we provide the most up-to-date mtDNA phylogeny (i.e. haplogroup tree or matrilineal genealogy) and a standardized hierarchical haplogroup nomenclature system for domesticated cattle, dogs, goats, horses, pigs, sheep, yaks and chickens. These high-resolution mtDNA haplogroup trees based on 1240 complete or near-complete mtDNA genome sequences are available in open resource DomeTree (http://www.dometree.org). In addition, we offer the software MitoToolPy (http://www.mitotool.org/mp.html) to facilitate the mtDNA data analyses. We will continuously and regularly update DomeTree and MitoToolPy.

In the past decade, a high incidence of somatic mitochondrial DNA (mtDNA) mutations has been observed, mostly based on a fraction of the molecule, in various cancerous tissues; nevertheless, some of them were queried due to problems in data quality. Obviously, without a comprehensive understanding of mtDNA mutational profile in the cancerous tissue of a specific patient, it is unlikely to disclose the genuine relationship between somatic mtDNA mutations and tumorigenesis. To achieve this objective, the most straightforward way is to directly compare the whole mtDNA genome variation among three tissues (namely, cancerous tissue, para-cancerous tissue, and distant normal tissue) from the same patient. Considering the fact that most of the previous studies on the role of mtDNA in colorectal tumor focused merely on the D-loop or partial segment of the molecule, in the current study we have collected three tissues (cancerous, para-cancerous and normal tissues) respectively recruited from 20 patients with colorectal tumor and completely sequenced the mitochondrial genome of each tissue. Our results reveal a relatively lower incidence of somatic mutations in these patients; intriguingly, all somatic mutations are in heteroplasmic status. Surprisingly, the observed somatic mutations are not restricted to cancer tissues, for the para-cancer tissues and distant normal tissues also harbor somatic mtDNA mutations with a lower frequency than cancerous tissues but higher than that observed in the general population. Our results suggest that somatic mtDNA mutations in cancerous tissues could not be simply explained as a consequence of tumorigenesis; meanwhile, the somatic mtDNA mutations in normal tissues might reflect an altered physiological environment in cancer patients.

Background Archaeological studies have revealed a series of cultural changes around the Last Glacial Maximum in East Asia; whether these changes left any signatures in the gene pool of East Asians remains poorly indicated. To achieve deeper insights into the demographic history of modern humans in East Asia around the Last Glacial Maximum, we extensively analyzed mitochondrial DNA haplogroup M9a'b, a specific haplogroup that was suggested to have some potential for tracing the migration around the Last Glacial Maximum in East Eurasia. Results A total of 837 M9a'b mitochondrial DNAs (583 from the literature, while the remaining 254 were newly collected in this study) pinpointed from over 28,000 subjects residing across East Eurasia were studied here. Fifty-nine representative samples were further selected for total mitochondrial DNA sequencing so we could better understand the phylogeny within M9a'b. Based on the updated phylogeny, an extensive phylogeographic analysis was carried out to reveal the differentiation of haplogroup M9a'b and to reconstruct the dispersal histories. Conclusions Our results indicated that southern China and/or Southeast Asia likely served as the source of some post-Last Glacial Maximum dispersal(s). The detailed dissection of haplogroup M9a'b revealed the existence of an inland dispersal in mainland East Asia during the post-glacial period. It was this dispersal that expanded not only to western China but also to northeast India and the south Himalaya region. A similar phylogeographic distribution pattern was also observed for haplogroup F1c, thus substantiating our proposition. This inland post-glacial dispersal was in agreement with the spread of the Mesolithic culture originating in South China and northern Vietnam.