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Abstract Objective The purpose of this study was to investigate the long-term consequences on the cervical spine after Anterior transcorporeal percutaneous endoscopy cervical discectomy (ATc-PECD) from the biomechanical standpoint. Methods A three-dimensional model of the normal cervical spine C2-T1 was established using finite element method. Subsequently, a disc degeneration model and degeneration with surgery model were constructed on the basis of the normal model. The same loading conditions were applied to simulate flexion, extension, lateral bending and axial rotation of the cervical spine. We calculated the cervical range of motion (ROM), intradiscal pressure, and intravertebral body pressure under different motions for observing changes in cervical spine biomechanics after surgery. At the same time, we combined the results of a long-term follow-up of the ATc-PECD, and used imaging methods to measure vertebral and disc height and cervical mobility, the Japanese Orthopaedic Association (JOA) score and visual analog scale (VAS) score were used to assess pain relief and neurological functional recovery. Results The long-term follow-up results revealed that preoperative JOA score, neck VAS score, hand VAS score, IDH, VBH, and ROM for patients were 9.49 ± 2.16, 6.34 ± 1.68, 5.14 ± 1.48, 5.95 ± 0.22 mm, 15.41 ± 1.68 mm, and 52.46 ± 9.36° respectively. It changed to 15.71 ± 1.13 (P

Abstract Although it is well documented that mountains tend to exhibit high biodiversity, how geological processes affect the assemblage of montane floras is a matter of ongoing research. Here, we explore landform-specific differences among montane floras based on a dataset comprising 17,576 angiosperm species representing 140 Chinese mountain floras, which we define as the collection of all angiosperm species growing on a specific mountain. Our results show that igneous bedrock (granitic and karst-granitic landforms) is correlated with higher species richness and phylogenetic overdispersion, while the opposite is true for sedimentary bedrock (karst, Danxia, and desert landforms), which is correlated with phylogenetic clustering. Furthermore, we show that landform type was the primary determinant of the assembly of evolutionarily older species within floras, while climate was a greater determinant for younger species. Our study indicates that landform type not only affects montane species richness, but also contributes to the composition of montane floras. To explain the assembly and differentiation of mountain floras, we propose the ‘floristic geo-lithology hypothesis’, which highlights the role of bedrock and landform processes in montane floristic assembly and provides insights for future research on speciation, migration, and biodiversity in montane regions.

A new spleenwort species, Asplenium guodanum, was found and described from Danxia landform region in Guangdong, China. The new species has close resemblance to A. subcrenatum Ching ex S.H.Wu in morphology, but can be distinguished by having plants small, stipes and rachises not covered with fibrous scales, relatively fewer pairs of pinnae, pinnae short, pinna margin weakly biserrate, pinna apex acute and lower pinnae obviously reduced. Phylogenetic analyses, based on six plastid markers (atpB, rbcL, rps4 & rps4-trnS and trnL & trnL-F) of the new species and its relatives, support a close relationship between A. guodanum and A. subcrenatum. Only one population with no more than 50 individuals were found and, therefore, it is recommended to be classified as Critically Endangered (CR) following IUCN Red List Criteria.

Abstract Objective Full endoscopic techniques are being gradually introduced from single-segment cervical disc herniation surgery to two-segment cervical disc herniation surgery. However, there is no suitable full endoscopic treatment for mixed-type two-segment cervical disc herniation (MTCDH) in which one segment herniates in front of the spinal cord and the other segment herniates behind the spinal cord. Therefore, we introduce a new full endoscopic technique by combining an anterior transcorporeal approach and a posterior translaminar approach. In addition, we provide a brief description of its safety, efficacy, feasibility, and surgical points. Methods Thirty patients with MTCDH were given full endoscopic surgical treatment by a combined transcorporeal and transforaminal approach and were followed up for at least 12 months. Results Clinical assessment scales showed that the patient’s symptoms and pain were significantly reduced postoperatively. Imaging results showed bony repair of the surgically induced bone defect and the cervical Cobb angle was increased. No serious complications occurred. Conclusion This technique enables minimally invasive surgery to relieve the compression of the spinal cord by MTCDH. It avoids the fusion of the vertebral body for internal fixation, preserves the vertebral motion segments, avoids medical destruction of the cervical disc to the greatest extent possible, and expands the scope of adaptation of full endoscopic technology in cervical surgery.

A new species of the genus Camellia (Theaceae), Camellia zijinica, discovered in the Danxia landscape from Guangdong Province, China, is characterized and illustrated. Phylogenetic analysis based on chloroplast genomes suggested its affinity with C. drupifera, C. oleifera and C. fluviatilis, however, it morphologically differs from all of the latter by leaf shape and size. Phonologically, it most closely resembles C. microphylla, but can be distinguished from the latter by its young branchlets glabrous (vs. densely pubescent), fewer bracteoles and sepals, diverse leaf shape, midvein raised slightly with sparsely pubescent or glabrous (vs. prominently with densely pubescent) and leaf adaxially matt (vs. vernicose) when dried. By morphological and molecular analyses, Camellia zijinica represented a distinct new species of C. sect. Paracamellia.

Lysimachia danxiashanensis, a new Primulaceae species, endemic to the Danxia landscape in Guangdong Province, China, is described and illustrated. This new species is morphologically similar to L. pseudohenryi, L. phyllocephala, L. congestiflora and L. kwangtungensis, but it differs from the similar species by its purplish-red plants, petiole without wings, calyx with orange glandular and the corolla margin serrated on upper half with orange-red glandular punctates. This new species belongs to Lysimachia subgen. Lysimachia sect. Nummularia. Phylogenetic analysis confirmed that L. danxiashanensis is a distinct clade, based on the combined data of ITS and rbcL sequences. The conservation status of the new species was evaluated as Endangered (EN) according to IUCN Red List Categories and Criteria.

Abstract Background The current treatments for adjacent two-segment cervical spondylotic myelopathy (CSM) include two-segment anterior cervical discectomy and fusion (ACDF) and single-segment anterior cervical corpectomy and fusion (ACCF). Long-term follow-up has demonstrated that both procedures have complications such as reduced cervical mobility, accelerated degeneration of adjacent segments and loosening of internal fixation screws. The purpose of this study is to demonstrate the feasibility, safety, and efficacy of anterior percutaneous full-endoscopic transcorporeal decompression of the spinal cord (APFETDSC) via one vertebra with two bony channels for the treatment of adjacent two-segment CSM and to present our surgical experience. Methods Anterior percutaneous full-endoscopic transcorporeal decompression of the spinal cord (APFETDSC) via one vertebra with two bony channels was performed for 12 patients with adjacent two-segment CSM with follow-up care for at least 12 months. The Visual analog scale (VAS) and the Japanese Orthopedic Association Score (JOA) were recorded, and modified Macnab criteria were used to evaluate the treatment excellence rate. Radiological examinations, including X-ray, computed tomography (CT) and magnetic resonance imaging (MRI), were used to evaluate spinal cord decompression, intervertebral stability and healing of the bony channel. Results All 12 patients completed the operation successfully. No postoperative complications, such as dysphagia, Horner’s syndrome, or laryngeal recurrent nerve palsy, were found. The postoperative VAS and JOA scores were significantly improved compared with those before surgery(P

Abstract Background Evaluate the effectiveness of posterior percutaneous full-endoscopic technique for patients with thoracic myelopathy caused by ossification of ligamentum flavum (TOLF). Methods A prospective study was conducted for 16 patients with TOLF, who were treated with posterior endoscopic technique from 2017 to 2019. The sagittal and cross-sectional CT images are used to measure the area of ossified ligamentum and evaluate the decompression of surgery, respectively. The effectiveness was evaluated with visual analog scale (VAS), modified Japanese Orthopedic Association scale (mJOA), The Oswestry Disability Index (ODI), and Macnab efficacy evaluation. Results The average area of TOLF on sagittal and cross-sectional CT images in the 16 patients was (116.62 ± 32.72) mm2 and (141.59 ± 27.25) mm2 preoperatively, (15.99 ± 12.54) mm2 and (11.72 ± 8.64) mm2 at 3 days after the operation, (16.78 ± 11.49) mm2 and (10.82 ± 7.57) mm2 postoperative 1 year, respectively. The invasive proportion of spinal canal at preoperative sagittal and cross-sectional CT images was (48.10 ± 10.04) % and (57.58 ± 11.37) %, which decreased to (6.83 ± 4.48) % and (4.40 ± 3.01) % at the final follow-up. The average score of mJOA, VAS and ODI improved. The excellent and good rate was 87.50% according to Macnab evaluation. Compared with preoperative, differences in areas of TOLF, proportions of spinal canal, and clinical assessments of postoperative 3 days and 1 year were all statistically significant. Two cases of dural tear were observed. Conclusion Endoscopic surgery has a good clinical effect on TOLF, which has the advantage of less trauma to the paraspinal muscles and no impact on the spinal structure. The CT-based radiographic measurements can quantitatively evaluate the degree of spinal canal stenosis in TOLF.

Commelina danxiaensis (Commelinaceae), a remarkable new species from Mount Danxia, Guangdong Province, China, is described and illustrated. This species is similar to C. communis in inflorescences and flowers but readily distinguishable in its nearly erect stems, larger flowers, and different petal colouration.

Argostemma ehuangzhangense, a new Rubiaceae species from E’huangzhang Nature Reserve, Guangdong Province, China, is here described and illustrated. A morphological comparison between the new species and its putative relatives, A. lamxayanum, A. laotica and A. verticillatum, is presented. The new species is mostly similar to A. laotica, but they can be distinguished from each other since Argostemma ehuangzhangense presents solitary flower (vs. 2-flowered inflorescences), flower lobes 4 (vs. 5) and anthers opening by longitudinal slits (vs. apical pores). In a preliminary IUCN Red List status of Argostemma ehuangzhangense this species is assigned as Vulnerable (VU).

The new species Eriobotrya crassifolia, collected from Yunnan Province, China, is characterised and illustrated. A phylogeny based on chloroplast genomes supported its closest affinity with E. tengyuehensis, while a phylogeny based on 197 single-copy nuclear genes supported its closest affinity with E. fragrans and E. deflexa. Morphologically, however, it resembles E. angustissima. Nevertheless, it can be easily distinguished from E. angustissima by its abaxially retroflexed and sharply serrate leaf margins, densely rusty tomentose inflorescences, and oblong or elliptic leaves.

A new species, Wikstroemia fragrans (Thymelaeaceae, Daphneae), from Danxiashan National Park, Shaoguan, Guangdong of China is described and illustrated. It is similar to the sympatric W. trichotoma, but can be differentiated easily from the latter by its shorter racemose inflorescences, yellowish green calyx tube, and smaller leaves. It also resembles the allopatric W. fargesii, but differs from it by its strigose-pubescent ovary and disk scale that is 2- or 3-dentate apically. Phylogenetic analysis using the nuclear DNA internal transcribed spacer (ITS) region revealed that W. fragrans falls within the Wikstroemia clade; based on current sampling, W. fragrans is closely-related to W. capitata. It is also the first species of Wikstroemia known to be endemic to the Danxia landform and is classified provisionally as Critically Endangered according to the IUCN Red List Categories and Criteria.

Pilea danxiaensis L.F.Fu, A.K.Monro & Y.G.Wei, a new species of Urticaceae from Danxia landform, Guangdong, China, is described and photographed. Phylogenetic analyses based on three DNA regions (ITS, trnL-F and rbcL) suggest that the new species belongs to P. sect. Pilea. Within the section, the new species is morphologically most similar to P. sinocrassifolia and P. peploides. Plastid genome and ribosomal DNA (rDNA) sequences of the new species are assembled and annotated. The plastid genome is 151,857 bp in length and comprises two inverted repeats (IRs) of 25,307 bp separated by a large single-copy of 82,836 bp and a small single-copy of 18,407 bp. A total of 113 functional genes are recovered, comprising 79 protein-coding genes, 30 tRNA genes, and four rRNA genes. A global conservation assessment suggests that P. danxiaensis should be classified as of Least Concern (LC).

Paraphlomis jinggangshanensis (Lamiaceae), a new species from Jiangxi Province, China, is described and illustrated. The new species is morphologically similar to P. intermedia, but can be easily distinguished from the latter by its cordate leaf base (vs. cuneate, decurrent), stem and calyx tube with glandular hairs (vs. short pubescent), and glabrous anthers (vs. ciliate anthers). A phylogenetic analysis, based on ITS regions, suggests that P. jinggangshanensis represents a separate branch in Paraphlomis and is closely related to Clade II. It is currently known only from Jinggangshan National Natural Reserve. Because of its limited distribution and small population size, the species was assessed as Near Threatened (NT) according to the IUCN Red List Categories and Criteria.

Asplenium jiulianshanense, a new tetraploid fern species of the A. normale complex (Aspleniaceae) from Jiulianshan National Nature Reserve, southern Jiangxi, China is described and illustrated. We inferred the phylogenetic position of the new species based on sequences from seven plastid markers (atpB, rbcL, rps4, rps4-trnS, trnL, trnL-F, and trnG) and one low-copy nuclear gene, pgiC. The plastid phylogeny supported a close relationship among the new species A. jiulianshanense, A. minutifolium, and A. kiangsuense, while the nuclear phylogeny differed in topology from the plastid tree. The new species may be due to hybridization between A. kiangsuense and A. boreale. Morphologically, the new species can easily be distinguished from other members of the A. normale complex by rachises bearing a gemma near the apex, pinna margins entire to sparsely crenate, and (1‒)3‒4(‒6) sori per pinna.

The diverse members of the genus Daphne are prized for their fragrant flowers. Despite being promising ornamental plants in many countries, genetic information of Daphne is scarce. In this study, the plastomes of four species and one variety of Daphne were sequenced and analyzed. The plastomes were typical and contained a pair of inverted repeat (IR) regions that separated the large single-copy (LSC) region from the small single-copy (SSC) region. With a length ranging from 132,869 bp (D. genkwa) to 174,773 bp (D. championii), 106 to 141 genes were predicted. Comparative plastome analysis of the newly sequenced plastomes with four publicly available Daphne plastomes identified an expansion of the IRs, sequence variations, and mutational hotspots. Phylogenetic analyses indicated that the genus Daphne in its current circumscription is polyphyletic. Daphne genkwa was nested within the genus Wikstroemia, while D. championii was well resolved as sister to Edgeworthia. These findings concurred with results from our study that used nuclear ribosomal internal transcribed spacer sequence data. The conflicts on the molecular placement of D. championii and D. genkwa and the present taxonomic classification in Daphne suggest that a new intergeneric classification system of Daphneae warrants consideration.

Viola huizhouensis (Violaceae), a new species from Xiangtoushan National Nature Reserve of Guangdong Province in China, is described and illustrated. The new species is most similar to V. guangzhouensis, but it can be easily distinguished by its much stouter rhizome, lack of aerial stem, dense pubescence of the basal pedicel and the whole plant. Our phylogenetic analysis, based on ITS sequences, confirms that the new species belongs to V. sect. Diffusae.

The Asplenium coenobiale complex is distributed in Eastern Asia and Southeast Asia with its distribution center in southwestern China. In this study, we carried out a detailed morphological, cytological, and phylogenetic study by adding two samples from Danxia landform in Guangdong. The sequences of five chloroplast markers and one nuclear marker of the A. coenobiale complex were analyzed with maximum likelihood and Bayesian inference, respectively. The morphological and phylogenetic analyses support the recognition of a new species (A. danxiaense K.W.Xu sp. nov.) of the A. coenobiale complex from a cave of Danxia mountain, Guangdong province, southern China. This new species can be distinguished from A. coenobiale and A. pulcherrimum by having scales narrowly triangular to lanceolate, apex ending in a short apical tail, basal basiscopic pinnule usually largest, fertile segment scarce, and exospore length usually more than 50 μm and shows significant molecular differences from other species in this complex. A detailed description and illustrations are presented.

We demonstrate with morphological characters that the species Pterostyrax burmanicus W.W.Sm. & Farrer and Parastyrax macrophyllus C.Y.Wu & K.M.Feng (Styracaceae) are best placed in the genus Rehderodendron Hu. Rehderodendron burmanicum (W.W.Sm. & Farrer) W.Y.Zhao, P.W.Fritsch & W.B.Liao, comb. nov. and Rehderodendron macrophyllum (C.Y.Wu & K.M.Feng) W.Y.Zhao, P.W.Fritsch & W.B.Liao, comb. nov., are created. We also provide a lectotype for R. macrophyllum. These revisions result in the reduction of Pterostyrax Siebold & Zucc. to three species and this genus is no longer considered to be documented from Myanmar. Further, Parastyrax W.W.Sm. becomes a monotypic genus comprising only P. lacei (W.W.Sm.) W.W.Sm., distributed in Kachin State, northeast Myanmar and Yunnan Province, south-western China.

Eriobotrya laoshanica, a new species of Rosaceae from Yunnan, China, is described and illustrated. The new species is easily distinguished from the most similar species E. malipoensis K. C. Kuan by its longer petioles (2–5 vs. 0.5–1 cm); indumentum on the lower leaf surfaces (densely tomentose vs. glabrous); much fewer flowers (15- to 30-flowered vs. 50- to 100-flowered) on the panicle; larger flowers (2.5–3 vs. 1.5–2 cm in diameter); and non-angulated (vs. angulated) young fruits.

Saxifraga damingshanensis (Saxifragaceae), a new species from Damingshan Nature Reserve in Guangxi Province, is described and illustrated. A morphological comparison between the new species and its putative relatives, S. mengtzeana and S. luoxiaoensis, is presented. The new species is morphologically similar to S. mengtzeana, but it can be easily distinguished by its non-peltate leaf, both surfaces of mature leaf blade covered with white glandular trichome, petals 3-veined and margin entire. Phylogenetic analysis, based on two chloroplast DNA regions (matK and psbA-trnH), confirmed that the new species belongs to S. sect. Irregulares. The new species is currently only known from Damingshan, Guangxi and we assign it an IUCN Red List preliminary status as Data Deficient.

Abstract Background Compared to anterior cervical discectomy and fusion (ACDF), cervical motion segment and disc was retained through anterior transcorporeal herniotomy (ATH). But surgical field and manipulation in traditional ATH was restricted by the narrow channel. Percutaneous full-endoscopic transdiscal cervical discectomy is a minimally invasive and functional spine surgery. However, significant loss of intervertebral disc height was inevitable. This study was done to illustrate the feasibility, safety, and efficacy and present our surgical experience of percutaneous full-endoscopic anterior transcorporeal cervical discectomy (PEATCD) and channel repair (CR) for the treatment of cervical disc herniation (CDH). Methods Four patients with CDH were chosen to undergo PEATCD and CR with a follow-up care for at least 22 months. The visual analogue score (VAS), Japanese Orthopedic Association (JOA), and modified Macnab criteria were recorded during the postoperative periods. CT images were obtained to observe the healing of the channel at 1 week and 3 months after the operation. Results The average operating time was 83.75 min. Drainage tubes were unnecessary. No procedure-related complications occurred. The postoperative VAS and JOA scores were improved compared to those of the preoperative assessment. The clinical efficacy was excellent in 3 patients and good in 1 patient at final follow up stage according to the modified Macnab criteria. The hernia was removed completely in all patients according to postoperative MRI. Migration of the repair implementation and collapse of the drilled vertebrae were not observed during the postoperative periods. The bony channel was nearly absent on CT images obtained at 3 months postoperative. Conclusion This is the first time that the anterior transcorporeal cervical discectomy and CR have been performed simultaneously under endoscopy. Less damage to disc and the retained cervical motion segment were achieved through this method. This is a feasible, safe, and minimally invasive procedure. Trial registration Numbers: ChiCTR1800016383. Registered 29 may 2018. Retrospectively registered. Trial registry: Chinese Clinical Trial Registry.

Background/Aims: β-Elemene is a bioactive sesquiterpene compound that exhibits a potent anti-tumor effect and is used in various clinical applications. However, little is known about its effect on the male reproductive system. The objective of this study was to investigate the in vitro actions of β-elemene on human sperm function and elucidate the underlying mechanism. Methods: The cytotoxicity of β-elemene toward MCF-10A, MDA-MD-231, and A549 cells was evaluated with cell proliferation and colony formation assays. Additionally, human sperm were treated with different concentrations (0, 10, 20, 40, 80, 160, and 320 µM) of β-elemene in vitro. The characteristics in human sperm essential for fertilization, including vitality, motility, capacitation, acrosome reaction, responsiveness to progesterone, and intracellular calcium concentration ([Ca2+]i) were examined with a computer-assisted sperm analysis system, chlortetracycline staining, and a fluorescent Ca2+ indicator. Results: A comprehensive evaluation of sperm motility, especially hyperactivated motility, revealed that treatments with 40–320 μM β-elemene decreased human sperm vitality, motility (total motility, progressive motility, and curvilinear velocity), and penetrating ability in a dose-dependent manner, but were non-toxic or minimally toxic toward MCF-10A, MDA-MD-231, and A549 cells. Although 10 and 20 μM β-elemene did not affect sperm vitality and motility, these concentrations increased the spontaneous acrosome reaction and inhibited progesterone-induced sperm functions by affecting sperm [Ca2+]i. Conclusion: These results suggest that β-elemene inhibits human sperm function by affecting sperm vitality and [Ca2+]i. These observations must be considered when using β-elemene to treat cancer patients who may wish to preserve their fertility.

Diversity is mainly determined by climate and environment. In addition, topography is a complex factor, and the relationship between topography and biodiversity is still poorly understood. To understand the role of topography, i.e., altitude and slope, in biodiversity, we selected Jinggangshan Mountain (JGM), an area with unique topography, as the study area. We surveyed plant and animal species richness of JGM and compared the biodiversity and the main geographic characteristics of JGM with the adjacent 4 mountains. Gleason's richness index was calculated to assess the diversity of species. In total, 2958 spermatophyte species, 418 bryophyte species, 355 pteridophyte species and 493 species of vertebrate animals were recorded in this survey. In general, the JGM biodiversity was higher than that of the adjacent mountains. Regarding topographic characteristics, 77% of JGM's area was in the mid-altitude region and approximately 40% of JGM's area was in the 10°-20° slope range, which may support more vegetation types in JGM area and make it a biodiversity hotspot. It should be noted that although the impact of topography on biodiversity was substantial, climate is still a more general factor driving the formation and maintenance of higher biodiversity. Topographic conditions can create microclimates, and both climatic and topographic conditions contribute to the formation of high biodiversity in JGM.

Many Firmiana species are locally endemic, providing an interesting system for studying adaptation and speciation. Among these species, F. danxiaensis is a tree species endemic to Mount Danxia in Guangdong, China, which is an area known for presenting the Danxia landform. How F. danxiaensis could have adapted to the stressful environment of rocky cliffs covered with barren soils in the Danxia landform is still unknown. In this study, we performed de novo assembly of the transcriptome of F. danxiaensis, obtaining 47,221 unigenes with an N50 value of 987 bp. Homology analysis showed that 32,318 of the unigenes presented hits in the NCBI non-redundant database, and 31,857 exhibited significant matches with the protein database of Theobroma cacao. Gene Ontology (GO) annotation showed that hundreds of unigenes participated in responses to various stresses or nutritional starvation, which may help us to understand the adaptation of F. danxiaensis to Danxia landform. Additionally, we found 263 genes related to responses to Cd, partially explaining the high accumulation of Cd observed in Firmiana species. The EuKaryotic Orthologous Groups (KOG) and Kyoto Encyclopedia of Genes and Genomes (KEGG) annotations revealed many genes playing roles in the biosynthesis of secondary metabolites and environmental adaptation, which may also contribute to the survivor and success of Firmiana species in extreme environments. Based on the obtained transcriptome, we further identified a Firmiana-specific whole-genome duplication event that occurred approximately 20 Mya, which may have provided raw materials for the diversification of Firmiana species.

The article discusses research which examined the possible mediation of the relationship between predation risk and crypsis by brain size. Topics explored include the cognitive abilities of well-camouflaged animals that help them evade predators, the use of reflectance measurements and visual modeling to assess the conspicuousness of anuran species from China, and observations relating to predation pressure, relative brain size, and hind leg muscle mass in the frogs studied.

Adaptations can endow species with complex traits that enable them to occupy new niches. To adapt to the arboreal lifestyle, treefrogs have evolved a suite of complex traits for climbing and gliding; to date, however, the molecular mechanisms underpinning these adaptations are unknown. Here, based on two de novo-assembled Asian treefrog genomes, genes related to limb development showed evidence of accelerated evolution. Furthermore, the PPL gene that regulates the keratin cytoskeleton showed conservative substitution within the genus Rhacophorus. These genetic changes contribute to limb and toe-pad morphogenesis, providing fundamental adaptations for climbing and grasping. Behavioral and morphological comparisons clarified the gliding function of interdigital webbing and the different developmental patterns between fully and weakly webbed feet. Time-ordered gene coexpression network analysis of gliding Rhacophorus kio and nongliding Rhacophorus dugritei tadpoles revealed specific coexpression patterns for fully webbed feet, which involved the Wnt signaling and vascular remodeling pathways. These findings highlight the molecular basis of phenotypes that facilitate expansion into new niches and provide insights into the importance of local adaptation in shaping phenotypes and locomotion patterns. [ABSTRACT FROM AUTHOR]

Conferring cognitive ability on animals, the brain is one of the most metabolically costly organs in vertebrates, and thus a large amount of energy associated with brain tissue maintenance should constrain brain size evolution. The expensive-tissue hypothesis (ETH) states that decrease in the sizes of other metabolically costly tissues compensates for increase in brain. In this paper, we tested ETH in a single species, Bufo gargarizans. We found no negative correlation between brain weight and intestinal length and no negative correlation between brain weight and the weight of other organs (heart, lungs, stomach, liver, kidneys, spleen, and testes). Therefore, our results do not support the ETH. We also found that intestinal length, stomach weight, liver weight and kidneys weight were positively correlated with each other, which may reflect the close functional relationships among these organs. However, a negative correlation was found between intestinal length and testes weight, indicating a trade-off between the testes and gut. Our findings suggest that energetic cost of a large brain in this species cannot be compensated by decreasing weight of other expensive organs. [ABSTRACT FROM AUTHOR]

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The brain is among the most energetically costly organs in the vertebrate body. The expensive-tissue hypothesis (ETH) predicts that increasing the size of another costly organ, such as the gut, should compensate for the cost of a small brain. To date, this hypothesis has mainly been tested in homoeothermic animals and in some ectothermic animals (e.g., fishes and anurans). Here, we undertake a test of the ETH by analyzing the relationship between brain size variation and length of the digestive tract in Hylarana guentheri. After controlling for geographical situation and body size, we did not find a correlation between brain mass and the length of the digestive tract in H. guentheri. Our findings suggest that the variation of brain size did not follow general patterns in this species and that the effect of diet quality cannot play a role in the variation of brain. [ABSTRACT FROM AUTHOR]

Brain size varies dramatically between vertebrate species. Two prominent adaptive hypotheses - the Cognitive Buffer Hypothesis (CBH) and the Expensive Brain Hypothesis (EBH) - have been proposed to explain brain size evolution. The CBH assumes that brain size should increase with seasonality, as the cognitive benefits of a larger brain should help overcoming periods of food scarcity via, for example, increased behavioral flexibility. Alternatively, the EBH states that brain size should decrease with seasonality because a smaller brain confers energetic benefits in periods of food scarcity. Here, to test the two adaptive hypotheses by studying the effects of variation in temperature and growth season on variations in overall brain size and the size of specific brain regions (viz. olfactory nerves, olfactory bulbs, telencephalon, optic tectum and cerebellum) among Hylarana guentheri populations. Inconsistent with the predictions of both the EBH and the CBH, variation in temperature and growth season did not exhibit correlations with overall brain size and the size of brain regions across populations. Hence, our data do not provide support for either the EBH or the CBH to explain brain size variation in H. guentheri. Furthermore, brain size variation did not differ between males and females in this species. Our findings suggest that both the variation in temperature and growth season did not shape the variation in brain size in H. guentheri. [ABSTRACT FROM AUTHOR]

The compensation hypothesis predicts that one testis may grow more for compensating for a reduced function in the other testis, thus exhibiting a directional asymmetry in testis size. In this study, we tested the prediction of the compensation hypothesis in the Chinese endemic Tree Frog Hyla gongshanensis jingdongensis in a population in Kegong Reserve site of Yunan Province in western China. For fifty-three male samplings, we found that the left testis size was significantly bigger than the right testis, which exhibited a significantly directional testis asymmetry, consistent with the evidence that mainly the left testis is functional with the right testis having a compensatory role, i.e. the left testis would increase in size if the right testis became non-functional. However, the relative testes size and the degree of testes asymmetry were not correlated with body condition in this species, suggesting that the testes asymmetry can not reflect male quality: high-quality individuals would not have more asymmetric testes. [ABSTRACT FROM AUTHOR]

The study of life-history traits in organisms mainly focuses on the female reproductive investment mode and its influencing factors. Offspring number and size as two plastic life-history traits, are commonly used to determine the reproductive investment. In this study, we evaluated the evolutionary trade-off between clutch size and egg size in the spot-legged treefrog (Polypedates megacephalus) along an altitudinal gradient. The results showed that females did not exhibit a significant correlation between body size, clutch size and egg size within each population, apart from the Leigong population. We did not find any evidence for the trade-off between clutch size and egg size within or among populations; however, clutch size and egg size from the highest-altitude population were larger than those from the lowest-altitude populations. Our findings suggest that the larger egg size may compensate for the increased mortality rates of their offspring at high altitudes. [ABSTRACT FROM AUTHOR]

Sexual size dimorphism (SSD), the difference in body size between males and females, is a widespread phenomenon and commonly attributed to variation in sex-specific patterns of selection. Using data from three populations of Polypedates megacephalus, we tested the hypotheses that sexual selection favoured large male body size and that fecundity selection favoured large female size. Females had a larger body size than males in all populations and thus exhibited a female-biased sexual size dimorphism. Standardized selection gradients showed that sexual selection for large male size was weak at best and hence unlikely to be an important driving force for SSD. As fecundity selection favouring large females was weak as well, it could not explain the female-biased SSD patterns found. However, a faster growth rate in females favoured a larger size, providing an explanation for female-biased SSD. Our findings suggest that female-biased SSD does not result from a phenotypic selection of female by size in P. megacephalus. [ABSTRACT FROM AUTHOR]

Phenotypic flexibility of morphological characters is widespread in the animal kingdom. In the present paper, we investigated altitudinal variation in organ size (heart, lungs, livers, kidneys and digestive tract) in the spotlegged treefrog (Polypedates megacephalus) across three populations along an altitudinal gradient in southwestern China. Both heart and lung mass increased with altitude, and is possibly linked to a lower oxygen supply at high elevations; a higher liver mass suggested the increased need for energy stores. Despite significant differences between populations, we found no distinct cline in the length of the digestive tract according to altitude. [ABSTRACT FROM AUTHOR]

Muscles are vital for the process of movement, mating and escape of predators in amphibians. During evolution, the morphological and genetic characteristics as well as the size of muscles in species will change to adapt different environments. Theory predicts that low male-male competition in highaltitude/ latitude selects for small limb muscles. Here, we used the Andrew's toad (Bufo andrewsi) as a model animal to test this prediction by analyzing geographical variation in the mass of limb muscles across nine populations from the Hengduan Mountains in China. Inconsistent with the prediction, we found that latitude and altitude did not affect the relative mass of total combined limb muscles and mass of combined hindlimb muscles among populations. Meanwhile, the relative mass of combined forelimb muscles, the two forelimb muscles (flexor carpi radialis and extensor carpi radialis) and the four hindlimb muscles (e.g. biceps femoris, semimebranous, semitendinosus and peroneus) was lowest in middle latitude and largest in low latitude whereas gracilis minor was largest in high latitudes. However, we did not find any correlations between the two forelimb muscles and the four hindlimb muscles and altitude. Our findings suggest that combined forelimb muscles, flexor carpi radialis, extensor carpi radialis, biceps femoris, semimebranous, semitendinosus and peroneus are largest in low latitudes due to pressures of mate competition. [ABSTRACT FROM AUTHOR]

Rensch's rule describes a pattern of allometry whereby sexual size dimorphism (SSD) increases with body size when males are the larger sex, and whereby SSD decreases with body size when females are larger by intraspecific comparison. In groups of related species or sets of conspecific populations, Rensch's rule has so far largely been confirmed with females being the larger sex in small-sized populations and males the larger sex in large-sized populations. The toad-headed lizard Phrynocephalus vlangalii is a small viviparous agamid endemic to China. It exhibits either male- or female-biased SSD depending on the population, and is therefore a good model species to test Rensch's rule relative to SSD direction. Using morphological data from 38 populations across the species' range, we studied whether populations with male- and female-biased SSD both exhibit isometric relationships consistent with Rensch's rule. For populations with male-biased SSD, we reject the hypothesis that SSD consistent with Rensch's rule is driven by allometries in tail length (in this species the tail is used for visual signalling during territory defence). In populations with female-biased SSD we find significant evidence for fecundity selection favouring large females, but Rensch's rule is not supported in this species. Our findings suggest that the underlying evolutionary forces (sexual and fecundity selection) do not promote the direction of SSD consistent with Rensch's rule in both male- and female-biased SSD across populations within a species. [ABSTRACT FROM AUTHOR]

Competition for fertilization in multi-male group spawning can drive variation in male reproductive investment (i.e., testis mass and sperm size). Inter-population comparisons of variation in energetic availability and allocation along geographical gradients allow insights into the mechanisms shaping the reproductive investments of animals. Although inter-population differences in female reproductive investment (i.e., clutch size and egg size) have been studied extensively across a wide range of taxa, little information on variation in reproductive investment in males is available. Here, we studied altitudinal variation in testis mass and sperm length among three populations in the Jingdong tree frog (Hyla gongshanensis jingdongensis), a polyandrous species, in Yunnan Province in China. The results showed that individuals exhibited smaller testes at higher altitudes while testes mass was positively correlated with body size, body condition and age. Longer sperm length was observed in the middlealtitude population. Moreover, we found that sperm number was positively correlated with testes mass and sperm length. Our correlational findings suggest that environmental constraints at high altitude select for less investment in testes and offspring number. [ABSTRACT FROM AUTHOR]

The digestive tract provides a functional relationship between energy intake and allocation. An understanding of effects of environmental factors on the evolution of digestive tract morphology is especially important. To investigate this, we studied the variation in digestive tract length across 10 populations of the Andrew's toad (Bufo andrewsi) between 2012 and 2015 in Sichuan province, western China. These populations were collected in different habitats varying in temperature and precipitation. The results reveal an increase in the length of the digestive tract and gut with increasing temperature and decreasing precipitation, when controlling for the effect of body size. Our findings suggest that individuals of populations living in high-temperature and low-precipitation environments have longer digestive tracts, possibly because they consume less animal-based foods and more highfiber foods. [ABSTRACT FROM AUTHOR]

Variation in temperature and breeding season length caused by altitude has long been considered a major influence on the evolution of life-history traits in amphibians. Here, we examined differences in reproductive investment (testes mass and sperm length) of male spot-legged treefrog (Polypedates megacephalus) from two altitudes (680 m and 1300 m above sea level) in Guizhou Province, western China. Relative testes size from the high-altitude population was larger than that of the low-altitude population, whereas sperm length exhibited a converse cline. Testes mass but not sperm length increased with body size at both altitudes. Our findings suggest that differences in reproductive traits between populations might result from differences in the level of sperm competition. [ABSTRACT FROM AUTHOR]

The brain is the most important organ associated with demands on cognitive ability, and selection pressures have been implicated to explain variation in brain size and brain architecture in a wide range of taxa. Using phylogenetic comparative methods, we studied the effect of spawning location (terrestrial, lentic and lotic) on variation in the size of different brain parts among 43 Chinese anuran species. Spawning location was not significantly associated with relative brain size, and there were no links between spawning location and independent contrasts in size of the olfactory bulbs, telencephalon, optic tecta and cerebellum. However, the independent contrasts in size of the olfactory nerves differed significantly among the three types of spawning location. Our findings provide evidence that the brain structures underlying olfaction are linked to lifehistory attributes required for spawning in specific habitat types. [ABSTRACT FROM AUTHOR]

Increased brain size significantly contributes to the performance and fitness of organisms. The expensive-tissue hypothesis (ETH) based on studies of the correlation between brain size and size of the other energetically costly organs in mammals predicts that energy investment increased in one energetically costly tissue necessitates a decrease of investments in other costly tissues. Here, we test this hypothesis in an ectothermic species, the dark-spotted frog, Pelophylax nigromaculatus. We found that relative brain size was not correlated with relative sizes of testes, heart, liver, spleen, kidneys or limb muscles within each sex. Moreover, we also failed to find significantly negative correlation among the expensive organs (i.e., testes, heart, liver, spleen, kidneys or limb muscles) in this frog. However, we observed a significantly positive correlation between liver residuals and kidney residuals. Our finding suggests that energetic costs of one expensive tissue do not direct necessarily affect the investment in another expensive tissue, but rather may scatter its effect on all other expensive tissues. [ABSTRACT FROM AUTHOR]

Background: Environmental variation associated with season length is likely to promote differentiation in lifehistory traits, but has been little studied in natural populations of ectotherms. We investigated patterns of variation in egg size, clutch size, age at sexual maturity, maximum age, mean age, growth rate and adult body size in relation to growth season length among 17 populations of Andrew's toad (Bufo andrewsi) at different latitudes and altitudes in the Hengduan Mountains, western China. Results: We found that egg size, age at sexual maturity, and mean age increased with decreasing length of the growth season, whereas clutch size showed a converse cline. Body size did not increase with decreasing length of the growth season, but was tightly linked to lifetime activity (i.e. the estimated number of active days during lifetime). Males and females differed in their patterns of geographic variation in growth rates, which may be the result of forces shaping the trade-off between growth and reproduction in different environments. Conclusions: Our findings suggest that growth season plays an important role in shaping variation in life-history traits in B. andrewsi across geographical gradients. [ABSTRACT FROM AUTHOR]

Brain size variation across the animal kingdom can be interpreted as a trade-off between selective advantages of higher cognitive ability and the prohibitively high energy demands of a large brain. The Expensive-Tissue Hypothesis (ETH) predicts that brains are costly, and increases in brain size will decrease the size of other metabolically costly tissues. Here, we tested this prediction using the anuran Rana omeimontis. Brain size was negatively correlated with gut length, supporting the ETH. We did not find associations between brain size and the size of other organs (heart, liver, lungs, kidneys), but found positive correlations between brain mass and testes as well as limb muscle mass when correcting for the effects of body condition. The negative correlation between gut length and brain mass suggests that diet quality may play a role in the evolution of brain size in R. omeimontis. [ABSTRACT FROM AUTHOR]

Sexual size dimorphism (SSD) is a widespread phenomenon commonly attributed to sex-specific patterns of selection on body size. Using data from Dengchigou population of the Omei treefrog (Rhacophorus omeimontis) in Fengtongzhai National Nature Reserve, southwestern China, we evaluated the hypothesis that direct phenotypic selection on both males and females can produce SSD. Female biased-SSD was generally driven by selection on females due to fecundity advantage of large body size rather than sexual selection favouring large male body size. Furthermore, differences in life-history traits (i.e. growth rate and/or time available for growth) between the sexes also resulted in female biased-SSD. Our findings suggest that the relationship between female size and fecundity supports the prediction that selection for fecundity drives female biased-SSD. [ABSTRACT FROM AUTHOR]