Genetically Encoded Lizard Color Divergence for Camouflage and Thermoregulation.

Local adaptation is critical in speciation and evolution, yet comprehensive studies on proximate and ultimate causes of local adaptation are generally scarce. Here, we integrated field ecological experiments, genome sequencing, and genetic verification to demonstrate both driving forces and molecular mechanisms governing local adaptation of body coloration in a lizard from the Qinghai-Tibet Plateau. We found dark lizards from the cold meadow population had lower spectrum reflectance but higher melanin contents than light counterparts from the warm dune population. Additionally, the colorations of both dark and light lizards facilitated the camouflage and thermoregulation in their respective microhabitat simultaneously. More importantly, by genome resequencing analysis, we detected a novel mutation in Tyrp1 that underpinned this color adaptation. The allele frequencies at the site of SNP 459# in the gene of Tyrp1 are 22.22% G/C and 77.78% C/C in dark lizards and 100% G/G in light lizards. Model-predicted structure and catalytic activity showed that this mutation increased structure flexibility and catalytic activity in enzyme TYRP1, and thereby facilitated the generation of eumelanin in dark lizards. The function of the mutation in Tyrp1 was further verified by more melanin contents and darker coloration detected in the zebrafish injected with the genotype of Tyrp1 from dark lizards. Therefore, our study demonstrates that a novel mutation of a major melanin-generating gene underpins skin color variation co-selected by camouflage and thermoregulation in a lizard. The resulting strong selection may reinforce adaptive genetic divergence and enable the persistence of adjacent populations with distinct body coloration.

Low diversity, little genetic structure but no inbreeding in a high-density island endemic pit-viper Gloydius shedaoensis.

Island species and their ecosystems play an important role in global biodiversity preservation, and many vulnerable island species are conservation priorities. Although insular habitat likely facilitates the species diversification process, it may also aggravate the fragility of these species with high risk of inbreeding. The Shedao pit-viper Gloydius shedaoensis is an island endemic species with an extremely high population density, which has been categorized as vulnerable in the IUCN (International Union for the Conservation of Nature and Natural Resources) Red List. We collected 13,148 SNP (Single Nucleotide Polymorphism) from across its genome and examined its genetic diversity and demographic history. The Shedao pit-viper has a low genetic diversity but shows no sign of inbreeding. Furthermore, population genetic structure analysis, including the neighbor-joining tree, principal coordinate analysis, clustering, and spatial autocorrelation, revealed a general lack of spatial structure. Only the isolation by distance residues suggested a weak patchiness. Overall, the population is nearly panmictic and gene flow is evenly distributed across the island. A large number of individuals, small size of the island, and the lack of population structure likely all contribute to the lack of inbreeding in this species. We also detected signs of male-biased dispersal, which likely is another inbreeding avoidance strategy. Historical demographic analysis suggested that the historical population size and distribution of the species are much larger than their current ones. The multiple transgressive-regressive events since the Late Pleistocene are likely the main cause of the population size changes. Taken together, our results provide a basic scientific foundation for the conservation of this interesting and important species.

Isolation and reconnection: Demographic history and multiple contact zones of the green odorous frog (Odorrana margaretae) around the Sichuan Basin.

The green odorous frog (Odorrana margaretae) displays a circular distribution around the Sichuan Basin of western China and possesses multiple replicate hybrid zones between lineages with high levels of divergence. To gain an understanding of the speciation process, we obtained 1540 SNPs from 29 populations and 227 individuals using ddRAD sequencing. Population structure analysis revealed three groups within the species: the West, North & South, and East groups. Demographic inference showed that they were initially isolated at ~2 million years ago, and subsequent post-glacial expansion produced the current circular distribution with four secondary contact zones. Hybridization in those zones involved lineages with various levels of divergence and produced greatly different patterns of introgression. Contact zones between the East and North & South groups (E-S and E-N) had contrast admixture levels but both showed a general lack of potential barrier loci. Meanwhile, the reconnection of the West and North & South groups produced two contact zones along the rim of the Basin. The S-W zone had extensive admixture while the N-W zone had limited admixture within a narrow geographic distance. Both showed substantial barrier effects, and a large number of potential barrier loci were shared. We also detected strong coupling among these loci. The N-W hybrid zone involved two highly-diverged lineages (FST = 0.704) and many loci have reached fixation around the hybrid zone. This study system offers a unique opportunity to understand the dynamics of introgression in contact zones and the architecture of reproductive isolation at different stages of speciation.

[Minimally invasive osteotomy and manual reduction for hallux valgus].

OBJECTIVE: To explore clinical effects of minimally invasive osteotomy and manual reduction in treating hallux valgus. METHODS: From January 2018 to May 2019, 31 patients (42 feet) with hallux valgus were treated with minimally invasive osteotomy and manual reduction, including 3 males and 28 females aged from 18 to 76 years old with an average of (50.1± 4.9) years old. Preoperative and postoperative hallux valgus (HVA), intermetatarsal angles(IMA), length difference between 1 and 2 metatarsals were recorded and compared, and American Orthopedic Foot and Ankle Society (AOFAS)score were observed and measured. RESULTS: Thirty-one patients (42 feet) were followed up from 14 to 18 months with an average of (15.1± 1.2) months. HVA, IM before operation were (38.5±5.4)°, (13.0± 1.1)°, and improved to (14.3±4.7)°and (9.1±1.5)°after operation respectively(P<0.05). Preopertaive length difference between 1 and 2 metatarsals was 2-4(-0.59±1.80) mm, and 0 to -6(-3.53±1.60) mm after operation, the average shortening of the first metatarsal was 2.94 mm. There were significant difference between preoperative and postoperative. Preoperative AOFAS score was 57.8±9.7, increased to 92.1±9.3 at the final follow-up, there was significant differences (P<0.05). According to standard of AOFAS score, 32 feet obtain excellent results, 16 good and 3 moderate. CONCLUSION: Minimally invasive osteotomy and manual reduction in treating hallux valgus have advantages of shorter operation time, less length of incision, and could correct hallux valgus deformity, improve front feet and receive good clinical effect in further.

Mechanical stress promotes angiogenesis through fibroblast exosomes.

BACKGROUND: Mechanical stress can induce multiple functional changes in vascular endothelial cells, including proliferation, differentiation, and migration. Furthermore, human fibroblasts are susceptible to external mechanical stress. In this work, we investigated whether mechanical stress can induce exosome secretion from fibroblasts to modulate angiogenesis. METHODS: A CCK-8 cell proliferation assay was used to determine mechanical parameters. Then, exosomes from fibroblasts were isolated and characterized with regard to concentration and markers. We subsequently explored the effect of exosomes on proliferation, migration, and angiogenesis. Additionally, high-throughput sequencing was used to screen differentially expressed miRNAs in the mechanical stress-induced exosomes. RESULTS: A static stretching of 15% significantly enhanced the cell viability of the fibroblasts (p < 0.05) and significantly induced the secretion of exosomes from the fibroblasts, which had a stronger internalization ability. Further experiments demonstrated that the presence of static stretching-induced exosomes significantly increased cell proliferation, migration, and angiogenesis by regulating the Erk1/2 signaling pathway. Additionally, 12 up-regulated and 12 down-regulated candidate miRNAs were discriminated in the static stretching-induced exosomes. CONCLUSION: Our findings conclusively demonstrate that static stretching-derived exosomes from fibroblasts promote angiogenesis through differentially expressed miRNAs, providing novel insights into the molecular mechanism by which mechanical stress influences angiogenesis.

Immobilization in external rotation versus internal rotation after shoulder dislocation: A meta-analysis of randomized controlled trials.

INTRODUCTION: Recurrence rates after primary traumatic shoulder dislocation are distinctly high. Whether the early external immobilization (ER) is better than the internal immobilization (IR) is still controversial. HYPOTHESIS: To perform a systematic review of randomized clinical trials (RCTs) that assessed the ability of external immobilization to reduce the recurrence in patients with primary anterior shoulder instability. MATERIAL AND METHOD: As with the original review, we used the search strategies recommended by the Cochrane Back Review Group for the identification of RCTs. Thirteen RCTs were included in the systematic review, and 11 studies were included in the quantitative synthesis. RESULT: A total of 1042 participants with primary shoulder dislocation were involved. The meta-analysis of 11 trials revealed that ER therapy leading to less recurrence rates than participants treated with IR therapy (RR=0.55; 95%CI: 0.36 to 0.82; Z=2.88; p=0.004), and less complications (RR=0.6; 95%CI: 0.39 to 0.92; Z=2.33; p=0.02) from the 5 independent trials. The meta-analysis of three trials revealed that there are not statistically significant in compliance rate (RR=1.08; 95%CI: 0.89 to 1.29; Z=0.78; p=0.44). The GRADE level of evidence is high for adverse events, but moderate for recurrence rate and Compliance rate. The Begg test showed that no significant publication bias was detected (p=0.062). DISCUSSION: This meta-analysis suggests that external immobilization is recommended to reduce the recurrence rate and prevent complications. LEVEL OF PROOF: II, low-powered systematic review and meta-analysis (systematic review, meta-analysis).

[Experts consensus statement on Cheezheng Xiaotong Tiegao in clinical practice].

Cheezheng Xiaotong Tiegao is a Tibetan traditional prescription,which has the functions of promoting blood circulation,relieving swelling and relieving pain. It has been widely used in various clinical departments such as orthopedics department,rheumatology department,pain management department,and rehabilitation department to treat all types of acute and chronic skeletal muscle pain. However,duet to the lack of detailed description of the specific use of various diseases in its manual,and in the published guidelines,monographs,and clinical reports,the introduction of the dominant clinical disease,usage,treatment,safety,etc. of Cheezheng Xiaotong Tiegao is not detailed. Therefore,this experts consensus statement has been prepared based on the research and analysis of clinicians and patients,evidence-based medical research and evaluation,combined with the experience of clinical experts. The experts consensus statement regulates usage,dosage,combination,safety,etc. in the treatment of acute and chronic contusion( soft tissue injury),osteoarthritis,low back pain,frozen shoulder,cervical spondylosis postoperative recovery pain and other pain relief and other skeletal muscle system diseases to provide evidence and reference for the rational and safety using of Cheezheng Xiaotong Tiegao.

Evolutionary melting pots and reproductive isolation: A ring-shaped diversification of an odorous frog (Odorrana margaratea) around the Sichuan Basin.

Quaternary climatic oscillations and geography are of primary importance in shaping intraspecific genetic diversity. We examined the diversification patterns and inferred processes for the green odorous frog (Odorrana margaretae) of western China. Species distribution modelling showed that the species has a continuous circular distribution around the Sichuan Basin while the basin itself is largely uninhabitable. Population genetic and phylogenetic analyses revealed that the species has a ring-shaped divergent pattern. While the chain of populations around the Basin maintains a mostly gradual and continuous genetic variation, populations between the north and west showed little gene exchange. Two processes, glacial refugial history and geography, likely contributed to the observed patterns. Our genetic clustering analysis revealed two clusters, suggesting two refugial groups among the populations, one from the west and the other from the east. Postglacial expansion may have created two contact zones. One at the south had extensive population admixture and produced a gradual transition between the western and eastern populations. Consequently, this region has the highest genetic diversity and represents an evolutionary "melting pot." In contrast, the second contact zone at the northwestern side of the Basin has limited admixture, suggesting partial reproductive isolation between the northern and western populations. Furthermore, an isolation-by-distance analysis revealed a strong correlation (Mantel r = 0.745) between the genetic and geographic distances, when we assumed that populations were connected following the circular distribution without gene flow across the NW contact zone. We also explored alternative explanations, such as a one-refugium scenario. With its micro-ring, the green odorous frog is poised to make an excellent model system for understanding the process of speciation.

Population Genetic Structure and Species Status of Asiatic Toads (Bufo gargarizans) in Western China.

We investigated the population genetic structure of Asiatic toads (Bufo gargarizans) from the mountains of western China to determine their species status, using genotypic data of ten microsatellite DNA loci and DNA sequences from one mitochondrial gene. A total of 197 samples from eight sites were examined, which cover a large range of elevations (559-3457 m), as well as all three traditionally defined species (or subspecies). AMOVA did not reveal any particularly large among-groups structure, whether the sites were grouped by drainage, elevation, region, or species (subspecies). Individual assignment tests placed all samples into two genetic clusters, which largely corresponded to their geographic locations. An isolation-by-distance pattern was also detected when an outlier population (site 3) was excluded. Furthermore, a mitochondrial gene tree revealed deep divergence among haplotypes, sometimes within the same site. The clade patterns were partially associated with geographic distribution but had no resemblance to the traditional 2- or 3-species classification. Overall, these toad populations harbor a large amount of genetic diversity and have very high population differentiation, but taken together the evidence suggests that all populations belong to a single species. Our results are consistent with most previous molecular studies, and we recommend using Bufo gargarizans to represent all Asiatic toad populations from western China without subspecies division.