Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 41
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Mol Biol Evol ; 41(3)2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38415852

RESUMO

Island organisms often evolve phenotypes divergent from their mainland counterparts, providing a useful system for studying adaptation under differential selection. In the white-winged fairywren (Malurus leucopterus), subspecies on two islands have a black nuptial plumage whereas the subspecies on the Australian mainland has a blue nuptial plumage. The black subspecies have a feather nanostructure that could in principle produce a blue structural color, suggesting a blue ancestor. An earlier study proposed independent evolution of melanism on the islands based on the history of subspecies divergence. However, the genetic basis of melanism and the origin of color differentiation in this group are still unknown. Here, we used whole-genome resequencing to investigate the genetic basis of melanism by comparing the blue and black M. leucopterus subspecies to identify highly divergent genomic regions. We identified a well-known pigmentation gene ASIP and four candidate genes that may contribute to feather nanostructure development. Contrary to the prediction of convergent evolution of island melanism, we detected signatures of a selective sweep in genomic regions containing ASIP and SCUBE2 not in the black subspecies but in the blue subspecies, which possesses many derived SNPs in these regions, suggesting that the mainland subspecies has re-evolved a blue plumage from a black ancestor. This proposed re-evolution was likely driven by a preexisting female preference. Our findings provide new insight into the evolution of plumage coloration in island versus continental populations, and, importantly, we identify candidate genes that likely play roles in the development and evolution of feather structural coloration.


Assuntos
Melanose , Passeriformes , Aves Canoras , Animais , Aves Canoras/genética , Austrália , Passeriformes/genética , Polimorfismo de Nucleotídeo Único , Plumas , Pigmentação , Cor
2.
Sci Data ; 11(1): 73, 2024 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-38228677

RESUMO

The White-eared Night-Heron (Gorsachius magnificus, G. magnificus) is a critically endangered heron that is very poorly known and only found in southern China and northern Vietnam, with an estimated population of 250 to 999 mature individuals. However, the lack of a reference genome has hindered the implementation of conservation management efforts. In this study, we present the first high-quality chromosome-scale reference genome, which was assembled by integrating PacBio long-reads sequencing, Illumina paired-end sequencing, and Hi-C technology. The genome has a total length of 1.176 Gb, with a scaffold N50 of 84.77 Mb and a contig N50 of 18.46 Mb. Utilizing Hi-C data, we anchored 99.89% of the scaffold sequences onto 29 pairs of chromosomes. Additionally, we identified 18,062 protein-coding genes in the genome, with 95.00% of which were functionally annotated. Notably, BUSCO assessment confirmed the presence of 97.2% of highly conserved Aves genes within the genome. This chromosome-level genome assembly and annotation will be valuable for future investigating the G. magnificus's evolutionary adaptation and conservation.


Assuntos
Aves , Cromossomos , Genoma , Animais , Aves/genética , Cromossomos/genética , Anotação de Sequência Molecular , Filogenia
3.
J Wildl Dis ; 59(4): 709-721, 2023 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-37768785

RESUMO

One of the major threats for the massive loss in global amphibian diversity is chytridiomycosis, caused by chytrid fungi Batrachochytrium dendrobatidis (Bd) and B. salamandrivorans (Bsal). Following its discovery in 2013, Bsal has emerged as a severe threat to the global survival of urodelans. In 2018, a study reported a high prevalence of Bsal (65.6%) in the Hong Kong newts (Paramesotriton hongkongensis, Near Threatened) of a southern China population adjacent to Hong Kong (HK). Uncertainty regarding the Bsal infection status of P. hongkongensis inhabiting HK raised deep concern over the risk of introducing Bsal from that population. We screened the skin swabs from wild individuals of P. hongkongensis, 15 sympatric amphibian species, and 16 imported amphibian species in HK for chytrids. We found that both Bsal and Bd occur in low prevalences in P. hongkongensis (Bsal 1.7%, 5/293; Bd 0.34%, 1/293), Hong Kong cascade frog, Amolops hongkongensis, family Ranidae (Bsal only, 5.26%, 1/19), and Asian common toad, Duttaphrynus melanostictus, family Bufonidae (Bsal only, 5.88%, 1/17), populations of HK, with infected individuals being asymptomatic, suggesting a potential role of these species as reservoirs of Bsal. Conversely, Bd, but not Bsal, was present on 13.2% (9/68) of imported amphibians, indicating a high chytrid introduction risk posed by international amphibian trade. Long-term surveillance of the presence of Bd and Bsal in wild and captive amphibians would be advisable, and we recommend that import and export of nonnative chytrid carriers should be prevented, especially to those regions with amphibian populations naïve to Bd and Bsal.


Assuntos
Batrachochytrium , Quitridiomicetos , Humanos , Animais , Hong Kong/epidemiologia , Anfíbios/microbiologia , Salamandridae , Bufonidae , Ranidae
4.
Mol Biol Evol ; 40(7)2023 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-37402641

RESUMO

Throughout the Plio-Pleistocene, climate change has impacted tropical marine ecosystems substantially, with even more severe impacts predicted in the Anthropocene. Although many studies have clarified demographic histories of seabirds in polar regions, the history of keystone seabirds of the tropics is unclear, despite the prominence of albatrosses (Diomedeidae, Procellariiformes) as the largest and most threatened group of oceanic seabirds. To understand the impact of climate change on tropical albatrosses, we investigated the evolutionary and demographic histories of all four North Pacific albatrosses and their prey using whole-genome analyses. We report a striking concordance in demographic histories among the four species, with a notable dip in effective population size at the beginning of the Pleistocene and a population expansion in the Last Glacial Period when sea levels were low, which resulted in increased potential coastal breeding sites. Abundance of the black-footed albatross dropped again during the Last Glacial Maximum, potentially linked to climate-driven loss of breeding sites and concordant genome-derived decreases in its major prey. We find very low genome-wide (π < 0.001) and adaptative genetic diversities across the albatrosses, with genes of the major histocompatibility complex close to monomorphic. We also identify recent selective sweeps at genes associated with hyperosmotic adaptation, longevity, and cognition and memory. Our study has shed light on the evolutionary and demographic histories of the largest tropical oceanic seabirds and provides evidence for their large population fluctuations and alarmingly low genetic diversities.


Assuntos
Evolução Biológica , Ecossistema , Animais , Variação Genética , Aves
5.
Am J Transl Res ; 15(2): 641-652, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36915777

RESUMO

OBJECTIVE: To compare the postoperative recovery of primary pterygium excision combined with either limbal stem cell transplantation (LSCT) or amniotic membrane transplantation (AMT). METHODS: All relevant studies on the primary pterygium excision combined with either LSCT or AMT conducted before August 2022 were extracted from PubMed, EMBASE, Web of Science, and Cochrane Library databases. The main outcomes compared were tear film stability at 1, 3, and 6 months after surgery, postoperative corneal epithelial healing time, recurrence rate, and complications. RESULTS: Sixteen randomized controlled trials (RCTs) with 1390 eye cases were included in this meta-analysis. We found that patients of the AMT group improved significantly in the results of the tear break-up time (BUT) and Schirmer I test at 1 month after surgery (BUT: MD=-0.37, 95% CI: -0.62, -0.12, P<0.05; Schirmer I test: MD=-0.32, 95% CI: -0.57, -0.07, P<0.05) compared with those of the LSCT group, suggesting that the early stage of tear film stability after primary pterygium excision combined with AMT was superior to the LSCT combination. However, according to the Schirmer I test result, the patients in the LSCT group showed increased tear production compared to the AMT group at 3 and 6 months after surgery (3 months: MD=0.36, 95% CI: 0.08, 0.64, P<0.05; 6 months: MD=0.33, 95% CI: 0.07, 0.60, P<0.05), suggesting that the LSCT combination was superior to the AMT combination in long-term postoperative tear film stability. As for postoperative corneal epithelial healing time, the LSCT group exhibited shorter time than the AMT group (MD=-1.17, 95% CI: -2.15, -0.19, P<0.05). Furthermore, the recurrence rate was lower in the LSCT group than in the AMT group (RR=0.42, 95% CI: 0.30, 0.59, P<0.05). Lastly, there was no statistical difference in BUT and complication rate at 3 and 6 months after surgery between the LSCT and AMT groups. CONCLUSIONS: Our analysis suggests that primary pterygium excision combined with LSCT may be a better choice compared to the combination with AMT in postoperative recovery.

6.
Parasit Vectors ; 16(1): 37, 2023 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-36707856

RESUMO

BACKGROUND: Understanding the interactions between bat flies and host bats offer us fundamental insights into the coevolutionary and ecological processes in host-parasite relationships. Here, we investigated the identities, host specificity, and patterns of host association of bat flies in a subtropical region in East Asia, which is an understudied region for bat fly research. METHODS: We used both morphological characteristics and DNA barcoding to identify the bat fly species found on 11 cavernicolous bat species from five bat families inhabiting Hong Kong. We first determined the phylogenetic relationships among bat fly species. Then, we elucidated the patterns of bat-bat fly associations and calculated the host specificity of each bat fly species. Furthermore, we assembled the mitogenomes of three bat fly species from two families (Nycteribiidae and Streblidae) to contribute to the limited bat fly genetic resources available. RESULTS: We examined 641 individuals of bat flies and found 20 species, of which many appeared to be new to science. Species of Nycteribiidae included five Nycteribia spp., three Penicillidia spp., two Phthiridium spp., one Basilia sp., and one species from a hitherto unknown genus, whereas Streblidae included Brachytarsina amboinensis, three Raymondia spp., and four additional Brachytarsina spp. Our bat-bat fly association network shows that certain closely related bat flies within Nycteribiidae and Streblidae only parasitized host bat species that are phylogenetically more closely related. For example, congenerics of Raymondia only parasitized hosts in Rhinolophus and Hipposideros, which are in two closely related families in Rhinolophoidea, but not other distantly related co-roosting species. A wide spectrum of host specificity of these bat fly species was also revealed, with some bat fly species being strictly monoxenous, e.g. nycteribiid Nycteribia sp. A, Phthiridium sp. A, and streblid Raymondia sp. A, while streblid B. amboinensis is polyxenous. CONCLUSIONS: The bat fly diversity and specificity uncovered in this study have shed light on the complex bat-bat fly ecology in the region, but more bat-parasite association studies are still needed in East Asian regions like China as a huge number of unknown species likely exists. We highly recommend the use of DNA barcoding to support morphological identification to reveal accurate host-ectoparasite relationships for future studies.


Assuntos
Quirópteros , Dípteros , Animais , Ásia Oriental , Dípteros/genética , Especificidade de Hospedeiro , Interações Hospedeiro-Parasita , Filogenia
7.
Mol Phylogenet Evol ; 175: 107580, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35810968

RESUMO

Several cryptic avian species have been validated by recent integrative taxonomic efforts in the Sino-Himalayan mountains, indicating that avian diversity in this global biodiversity hotspot may be underestimated. In the present study, we investigated species limits in the genus Tarsiger, the bush robins, a group of montane forest specialists with high species richness in the Sino-Himalayan region. Based on comprehensive sampling of all 11 subspecies of the six currently recognized species, we applied an integrative taxonomic approach by combining multilocus, acoustic, plumage and morphometric analyses. Our results reveal that the isolated north-central Chinese populations of Tarsiger cyanurus, described as the subspecies albocoeruleus but usually considered invalid, is distinctive in genetics and vocalisation, but only marginally differentiated in morphology. We also found the Taiwan endemic T. indicus formosanus to be distinctive in genetics, song and morphology from T. i. indicus and T. i. yunnanensis of the Sino-Himalayan mountains. Moreover, Bayesian species delimitation using BPP suggests that both albocoeruleus and formosanus merit full species status. We propose their treatment as 'Qilian Bluetail' T. albocoeruleus and 'Taiwan Bush Robin' T. formosanus, respectively.


Assuntos
Aves Canoras , Animais , Teorema de Bayes , Biodiversidade , Florestas , Filogenia
8.
Proc Biol Sci ; 288(1948): 20210073, 2021 04 14.
Artigo em Inglês | MEDLINE | ID: mdl-33823666

RESUMO

Both anthropogenic impacts and historical climate change could contribute to population decline and species extinction, but their relative importance is still unclear. Emerging approaches based on genomic, climatic and anthropogenic data provide a promising analytical framework to address this question. This study applied such an integrative approach to examine potential drivers for the endangerment of the green peafowl (Pavo muticus). Several demographic reconstructions based on population genomes congruently retrieved a drastic population declination since the mid-Holocene. Furthermore, a comparison between historical and modern genomes suggested genetic diversity decrease during the last 50 years. However, climate-based ecological niche models predicted stationary general range during these periods and imply the little impact of climate change. Further analyses suggested that human disturbance intensities were negatively correlated with the green peafowl's effective population sizes and significantly associated with its survival status (extirpation or persistence). Archaeological and historical records corroborate the critical role of humans, leaving the footprint of low genomic diversity and high inbreeding in the survival populations. This study sheds light on the potential deep-time effects of human disturbance on species endangerment and offers a multi-evidential approach in examining underlying forces for population declines.


Assuntos
Genoma , Metagenômica , Animais , Mudança Climática , Ecossistema , Extinção Biológica , Humanos
9.
Lab Invest ; 101(6): 760-774, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33753880

RESUMO

Endometrial carcinoma is one of the most common malignancies in the female reproductive system. Interleukin-37 (IL-37) is a newly discovered anti-inflammatory factor belonging to the IL-1 family. IL-37 has five different isoforms, and IL-37b is the most biologically functional subtype. In recent years, the protective roles of IL-37 in different cancers, including lung and liver cancers, have been successively reported. IL-37 also plays an important role in some gynecological diseases such as endometriosis, adenomyosis, and cervical cancer. However, the role and mechanism of IL-37b, especially the mature form of IL-37b, in endometrial carcinoma have not been elucidated. The present study demonstrated that IL-37 protein was downregulated in endometrial carcinoma cells compared with the control endometrium. IL-37b did not affect the proliferation and colony-forming ability of endometrial cancer cells. A mature form of IL-37b (IL-37bΔ1-45) effectively suppressed the migration and invasion of endometrial cancer cells by decreasing the expression of matrix metalloproteinase 2 (MMP2) via Rac1/NF-κB signal pathway. However, it did not affect epithelial-mesenchymal transition (EMT) or filamentous actin (F-actin) depolymerization of endometrial cancer cells. IL-37bΔ1-45 attenuated tumor metastasis in a peritoneal metastatic xenograft model of endometrial cancer. To sum up, these results suggested IL-37b could be involved in the pathogenesis of endometrial carcinoma and provide a novel target for the diagnosis and treatment of endometrial carcinoma.


Assuntos
Carcinoma Endometrioide/tratamento farmacológico , Neoplasias do Endométrio/tratamento farmacológico , Interleucina-1/uso terapêutico , Transdução de Sinais/efeitos dos fármacos , Actinas/metabolismo , Adulto , Idoso , Animais , Carcinoma Endometrioide/metabolismo , Linhagem Celular Tumoral , Neoplasias do Endométrio/metabolismo , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Estrogênios , Feminino , Humanos , Interleucina-1/metabolismo , Interleucina-1/farmacologia , Metaloproteinase 2 da Matriz/metabolismo , Camundongos Endogâmicos BALB C , Camundongos Nus , Pessoa de Meia-Idade , NF-kappa B/metabolismo , Progesterona , Ensaios Antitumorais Modelo de Xenoenxerto , Proteínas rac1 de Ligação ao GTP/metabolismo
10.
J Mol Neurosci ; 71(6): 1256-1265, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33205379

RESUMO

Spinal cord injury (SCI) is a devastating traumatic event worldwide. Work from the past decade has highlighted the key involvement of long non-coding RNAs (lncRNAs) in SCI. Nevertheless, the molecular action of lncRNA H19 in SCI is still not fully understood. The levels of H19, microRNA (miR)-325-3p, and neuronal differentiation 4 (NEUROD4) were determined by quantitative real-time polymerase chain reaction (qRT-PCR) or western blot. Flow cytometry was performed to assess cell apoptosis. The levels of tumor necrosis factor-α (TNF-α), interleukin 1ß (IL-1ß), and IL-6 were detected using the enzyme-linked immunosorbent assay (ELISA). Targeted relationships among H19, miR-325-3p, and NEUROD4 were confirmed by dual-luciferase reporter, RNA immunoprecipitation (RIP), or RNA pull-down assays. Our data showed that H19 level was overexpressed in lipopolysaccharide (LPS)-treated BV2 cells. H19 silencing alleviated LPS-evoked cell apoptosis and inflammation. Mechanistically, H19 in BV2 cells directly targeted miR-325-3p, and NEUROD4 was a direct target of miR-325-3p. Moreover, miR-325-3p was a functional target of H19 in regulating cell apoptosis and inflammation induced by LPS. Enforced expression of miR-325-3p relieved LPS-evoked cell apoptosis and inflammation through reducing NEUROD4. Furthermore, H19 in BV2 cells regulated NEUROD4 expression through targeting miR-325-3p. Our results identified that the silencing of H19 attenuated LPS-evoked microglia cell apoptosis and inflammation after SCI at least partially through targeting the miR-325-3p/NEUROD4 axis, highlighting a novel approach for SCI management.


Assuntos
Apoptose , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Microglia/metabolismo , Proteínas do Tecido Nervoso/genética , RNA Longo não Codificante/genética , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Linhagem Celular , Feminino , Interleucina-1beta/metabolismo , Interleucina-6/metabolismo , Lipopolissacarídeos/toxicidade , Camundongos , Camundongos Endogâmicos BALB C , MicroRNAs/genética , MicroRNAs/metabolismo , Microglia/efeitos dos fármacos , Proteínas do Tecido Nervoso/metabolismo , RNA Longo não Codificante/metabolismo , Fator de Necrose Tumoral alfa/metabolismo
11.
J Med Virol ; 93(5): 2838-2847, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33231312

RESUMO

The ongoing coronavirus disease 2019 (COVID-19) epidemic has made a huge impact on health, economies, and societies all over the world. Although reverse transcription-polymerase chain reaction (RT-PCR)-based nucleic acid detection has been primarily used in the diagnosis of COVID-19, it is time-consuming with limited application scenarios and must be operated by qualified personnel. Antibody test, particularly point-of-care antibody testing, is a suitable complement to nucleic acid test as it provides rapid, portable, and cost-effective detection of infections. In this study, a Rapid Antibody Test Kit was developed based on fluorescence immunochromatography for the sensitive, accurate, and automated detection of immunoglobulin M (IgM) and IgG antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in human serum, plasma, and whole blood samples within 10 min. The sensitivity, specificity, precision, and stability of the test kit were of good performance. No cross-activity and no interference was observed. In the multiple-center parallel study, 223 samples from hospitalized patients were used to evaluate the clinical specificity of the test. Both SARS-CoV-2 IgM and IgG achieved a clinical specificity of 98.21%. The clinical sensitivities of SARS-CoV-2 IgM and IgG were 79.54% and 87.45%, respectively, among 733 reverse transcription-polymerase chain reaction (RT-PCR) confirmed SARS-CoV-2 samples. For the combined IgM and IgG assays, the sensitivity and specificity were 89.22% and 96.86%, respectively. Our results demonstrate that the combined use of IgM and IgG could serve as a more suitable alternative detection method for patients with COVID-19, and the developed kit is of great public health significance for the prevention and control of the COVID-19 pandemic.


Assuntos
Anticorpos Antivirais/sangue , Teste para COVID-19/métodos , COVID-19/diagnóstico , Imunofluorescência/métodos , Imunoensaio/métodos , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Kit de Reagentes para Diagnóstico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , COVID-19/imunologia , Criança , Pré-Escolar , Feminino , Fluorescência , Humanos , Masculino , Camundongos , Pessoa de Meia-Idade , Testes Imediatos , Proteínas Recombinantes , SARS-CoV-2/imunologia , SARS-CoV-2/isolamento & purificação , Sensibilidade e Especificidade , Glicoproteína da Espícula de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/imunologia , Adulto Jovem
12.
Cancer Manag Res ; 12: 10809-10820, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33149686

RESUMO

INTRODUCTION: TRAIL (tumor necrosis factor-related apoptosis-inducing ligand) can induce apoptosis in a variety of cancer cells. However, drug resistance of tumor and short half-life seriously affects its clinical targeted therapy. Cabazitaxel (CTX) is a taxane drug, which can induce apoptosis or autophagy by inhibiting the phosphorylation of PI3K/Akt/mTOR and sensitive to some drug-resistant tumors. Therefore, we explored the possibility of developing a mesenchymal stem cell-derived exosomes (MSC-EXO) vector for oral squamous cell carcinoma (OSCC) to deliver CTX/TRAIL combinations. METHODS: After ultracentrifugation and dialysis, CTX/TRAIL loaded exosomes transfected MSC (MSCT)-derived exosome (EXO) (MSCT-EXO/CTX) were isolated and purified. The expression of CD63, CD9 and TRAIL was detected by BCA to confirm the origin of EXO. High-performance liquid chromatography (HPLC) was used to determine the drug loading of VPF and draw the in vitro release profile. MTT assay, flow cytometry and Western blot were used to detect the antitumor effect of MSCT-EXO/CTX in vitro. Subsequently, the antitumor effect of MSCT-EXO/CTX in vivo was verified by mouse model. RESULTS: The diameter of the membrane particles was about 60-150 nm. We have proved that the incorporation and release of CTX in MSCT-EXO can inhibit the activation of PI3K, Akt and mTOR, which is a possible synergistic mechanism of CTX. MSCT-EXO and CTX can induce the apoptosis of SCC25 tumor cells in a dose-dependent manner and exert a good synergistic effect in the proportion range of 10:1-5:1. The inherent activity of MSCT-EXO and the direct effect of MSCT-EXO/CTX on OSCC confirm that MSCT-EXO/CTX makes MSCT-EXO and CTX have an efficient synergistic effect and a highly effective pharmacological inhibition on cancer cells, as verified by the subsequent mouse model. MSCT-EXO/CTX showed the lowest relative tumor volume and the highest tumor inhibition rate (P<0.05) in vivo. CONCLUSION: An MSCT-EXO-based CTX delivery system might be an effective anticancer method.

13.
Transplant Proc ; 52(3): 982-986, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32113692

RESUMO

Immunologic and nonimmunologic mechanisms contribute to islet loss on transplantation in the liver. A site outside of the vascular bed may act as a sanctuary site avoiding immediate inflammatory response. We developed a unique approach by using a human amniotic membrane (HAM) for islet transplant onto the liver surface by combining it with human amniotic epithelial cells (HAECs). Decellularized 1.0 × 1.0-cm HAM was placed on the surface of the liver; 2000 islet equivalent of human islets mixed with 0.4 × 106 HAECs were infused into the space between the membrane and surface. Two pieces of the decellularized HAM were placed under the subcutaneous space to study the angiogenic potential. After cotransplant 57.1% of recipient mice became normoglycemic by the third day after transplant, and 100% attained euglycemia 2 weeks post-transplant. Bodyweight of 85.7% of mice gradually increased over time. The HAM and islets were identified in histologic section in all. Neovascularization was observed to be dramatically increased. In conclusion, HAM is a very versatile biological membrane; HAECs help angiogenesis and better engraftment of islets on the liver surface, eliminating the need for vascular deployment of islet cells and avoiding the risk of portal vein thrombosis and instant blood-mediated inflammatory reaction-related islet loss in the liver.


Assuntos
Âmnio , Células Epiteliais , Transplante das Ilhotas Pancreáticas/métodos , Animais , Sobrevivência de Enxerto , Humanos , Transplante das Ilhotas Pancreáticas/imunologia , Fígado , Camundongos
14.
PeerJ ; 7: e6643, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30918762

RESUMO

BACKGROUND: Captive populations permit research and conservation of endangered species in which these efforts are hardly implemented in wild populations. Thus, analysing genetic diversity and structure of captive populations offers unique opportunities. One example is the critically endangered Blue-crowned Laughingthrush, Garrulax courtoisi, which has only two known wild populations in Wuyuan, Jiangxi and Simao, Yunnan, China. We carried out the first conservation genetic study, in order to provide useful implications that allow for successful ex situ conservation and management of the Blue-crowned Laughingthrush. METHODS: Using the novel microsatellite markers developed by whole-genome sequencing, we genotyped two captive populations, from the Ocean Park Hong Kong, which are of unknown origin, and the Nanchang Zoo, which were introduced from the Wuyuan wild population since the year 2010-2011, respectively. The genetic diversity of captive Blue-crowned Laughingthrush populations was estimated based on genetic polymorphisms revealed by a new microsatellite data set and mitochondrial sequences. Then, we characterised the population structure using STRUCTURE, principal coordinates analysis, population assignment test using the microsatellite data, and haplotype analysis of mitochondrial data. Additionally, we quantified genetic relatedness based on the microsatellite data with ML-Relate. RESULTS: Our results showed equally low levels of genetic diversity of the two captive Blue-crowned Laughingthrush populations. The population structure analysis, population assignment test using the microsatellite data, and haplotype analysis of the mitochondrial data showed weak population structuring between these two populations. The average pairwise relatedness coefficient was not significant, and their genetic relatedness was quantified. DISCUSSION: This study offers a genetic tool and consequently reveals a low level of genetic diversity within populations of a critically endangered bird species. Furthermore, our results indicate that we cannot exclude the probability that the origin of the Hong Kong captive population was the wild population from Wuyuan. These results provide valuable knowledge that can help improve conservation management and planning for both captive and wild Blue-crowned Laughingthrush populations.

15.
Sci Rep ; 8(1): 15723, 2018 10 24.
Artigo em Inglês | MEDLINE | ID: mdl-30356056

RESUMO

Multiple nuclear markers provide genetic polymorphism data for molecular systematics and population genetic studies. They are especially required for the coalescent-based analyses that can be used to accurately estimate species trees and infer population demographic histories. However, in avian evolutionary studies, these powerful coalescent-based methods are hindered by the lack of a sufficient number of markers. In this study, we designed PCR primers to amplify 136 nuclear protein-coding loci (NPCLs) by scanning the published Red Junglefowl (Gallus gallus) and Zebra Finch (Taeniopygia guttata) genomes. To test their utility, we amplified these loci in 41 bird species representing 23 Aves orders. The sixty-three best-performing NPCLs, based on high PCR success rates, were selected which had various mutation rates and were evenly distributed across 17 avian autosomal chromosomes and the Z chromosome. To test phylogenetic resolving power of these markers, we conducted a Neoavian phylogenies analysis using 63 concatenated NPCL markers derived from 48 whole genomes of birds. The resulting phylogenetic topology, to a large extent, is congruence with results resolved by previous whole genome data. To test the level of intraspecific polymorphism in these makers, we examined the genetic diversity in four populations of the Kentish Plover (Charadrius alexandrinus) at 17 of NPCL markers chosen at random. Our results showed that these NPCL markers exhibited a level of polymorphism comparable with mitochondrial loci. Therefore, this set of pan-avian nuclear protein-coding loci has great potential to facilitate studies in avian phylogenetics and population genetics.


Assuntos
Aves/genética , Loci Gênicos/genética , Marcadores Genéticos/genética , Genética Populacional , Proteínas Nucleares/genética , Filogenia , Animais , Charadriiformes/genética , Galinhas/genética , Primers do DNA/genética , Variação Genética , Genoma , Polimorfismo Genético
16.
Mol Phylogenet Evol ; 127: 723-731, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29920336

RESUMO

Diversity and distributions of cryptic species have long been a vexing issue. Identification of species boundaries is made difficult by the lack of obvious morphological differences. Here, we investigate the cryptic diversity and evolutionary history of an underappreciated group of Asian frog species (Megophrys) to explore the pattern and dynamic of amphibian cryptic species. We sequenced four mitochondrial genes and five nuclear genes and delineated species using multiple approaches, combining DNA and mating-call data. A Bayesian species tree was generated to estimate divergence times and to reconstruct ancestral ranges. Macroevolutionary analyses and hybridization tests were conducted to explore the evolutionary dynamics of this cryptic group. Our phylogenies support the current subgenera. We revealed 43 cryptic species, 158% higher than previously thought. The species-delimitation results were further confirmed by mating-call data and morphological divergence. We found that these Asian frogs entered China from the Sunda Shelf 48 Mya, followed by an ancient radiation event during middle Miocene. We confirmed the efficiency of the multispecies coalescent model for delimitation of species with low morphological diversity. Species diversity of Megophrys is severely underappreciated, and species distributions have been misestimated as a result.


Assuntos
Anuros/anatomia & histologia , Anuros/genética , Evolução Biológica , Especiação Genética , Animais , Teorema de Bayes , Biodiversidade , China , Funções Verossimilhança , Filogenia , Filogeografia , Especificidade da Espécie , Simpatria , Fatores de Tempo , Vocalização Animal
17.
Mol Phylogenet Evol ; 125: 116-126, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29522814

RESUMO

Species not only responded idiosyncratically to past climate changes, there were also regionally contrasting effects on spatio-temporal diversification patterns. Studies of closely related species appear to be a particularly promising comparative approach to disentangle such regionally differential impacts. In this study, we undertook a comprehensive geographic sampling to investigate the evolutionary history of the Holarctic Sand Martin Riparia riparia and the chiefly Central and East Asian Pale Martin R. diluta. Previous phylogenetic studies using only a limited geographic sampling, particularly for the latter, revealed the two to be genetically distinct, with the former showing only a shallow genetic structure in mitochondrial DNA. Based on one mitochondrial, one autosomal and one Z-linked nuclear marker, we confirmed the shallow genetic structure in R. riparia even when including the morphologically relatively distinct subspecies R. r. shelleyi from the Nile Valley in Egypt and probably the Middle East. On the other hand the different subspecies of R. diluta, i.e. R. d. diluta from Central Asia, R. d. indica from the northwestern Indian Subcontinent, R. d. tibetana from the Tibetan Plateau and R. d. fohkienensis from southeastern China, were found to be genetically distinct. Their diversification started before the Early to Middle Pleistocene Transition, which was followed by a pronounced succession of glacial and interglacial periods. These rather old divergence events contrast with the lack of any strong phylogeographic structure in R. riparia. Strongly structured populations and regional diversification have been reported in different forest passerine families of South-East Asia. Here we demonstrate, however, that species characteristic of open-country habitats such as R. diluta might display a similar pattern. Morphometric analyses of 120 individuals revealed no clear differences between the different subspecies of R. diluta. Given their similarity also in plumage features, we refrain from proposing any splits despite their marked genetic differentiation, pending further studies and particularly the discovery of potential secondary contact zones.


Assuntos
Variação Genética , Andorinhas/genética , Animais , Sequência de Bases , Teorema de Bayes , Cruzamento , Calibragem , Núcleo Celular/genética , DNA Mitocondrial/genética , Marcadores Genéticos , Geografia , Haplótipos/genética , Filogenia , Filogeografia , Análise de Componente Principal , Especificidade da Espécie , Andorinhas/anatomia & histologia
18.
Oncol Lett ; 15(2): 1874-1880, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29434884

RESUMO

Endostatin has previously been demonstrated to efficiently inhibit the angiogenesis and growth of endothelial cells. However, the role of endostatin in the tumor microenvironment remains to be elucidated. To investigate the antitumor effect of endostatin in lung cancer, the present study was designed to explore the alterations of microvessel density in Lewis lung cancer models and the expression of vascular endothelial growth factor (VEGF), interleukin (IL)-6, IL-17, interferon (IFN)-γ and hypoxia inducible factor (HIF)-1α, following endostatin therapy. It was demonstrated that the growth and angiogenesis of tumors were markedly suppressed by treatment with endostatin, compared with control group. The microvessel density in mice treated with endostatin was significantly inhibited in a dose-dependent manner. The expression levels of VEGF, IL-6 and IL-17 in tumors were decreased, however IFN-γ and HIF-1α expression levels were increased, following treatment with endostatin. In addition, the proportion of myeloid derived suppressor cells and tumor associated macrophages (TAMs; M2 type) were significantly decreased, whereas those of mature dendritic cells and TAMs (M1 type) were increased, and cluster of differentiation (CD)8+ T cells were recruited to infiltrate the tumors following treatment with endostatin. In addition, the expression levels of IL-6, IL-10, tumor growth factor-ß and IL-17 in tumor tissue were potently decreased with endostatin therapy. These results indicated that endostatin efficiently inhibited tumor angiogenesis and reversed the immunosuppressive microenvironment associated with the presence of tumors.

19.
Islets ; 9(6): 140-149, 2017 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-28902579

RESUMO

BACKGROUND: The inflammatory milieu in the liver as determined by histopathology is different in individual patients undergoing autologous islet cell transplantation. We hypothesized that inflammation related to fatty-liver adversely impacts islet survival. To test this hypothesis, we used a mouse model of fatty-liver to determine the outcome of syngeneic islet transplantation after chemical pancreatectomy. METHODS: Mice (C57BL/6) were fed a high-fat-diet from 6 weeks of age until attaining a weight of ≥28 grams (6-8 weeks) to produce a fatty liver (histologically > 30% fat);steatosis was confirmed with lipidomic profile of liver tissue. Islets were infused via the intra-portal route in fatty-liver and control mice after streptozotocin induction of diabetes. Outcomes were assessed by the rate of euglycemia, liver histopathology, evaluation of liver inflammation by measuring tissue cytokines IL-1ß and TNF-α by RT-PCR and CD31 expression by immunohistochemistry. RESULTS: The difference in the euglycemic fraction between the normal liver group (90%, 9/10) and the fatty-liver group (37.5%, 3/8) was statistically significant at the 18th day post- transplant and was maintained to the end of the study (day 28) (p = 0.019, X2 = 5.51). Levels of TNF-α and IL-1ß were elevated in fatty-liver mice (p = 0.042, p = 0.037). Compared to controls cytokine levels were elevated after islet cell transplantation and in transplanted fatty-liver mice as compared to either fatty- or islet transplant group alone (p = NS). A difference in the histochemical pattern of CD31 could not be determined. CONCLUSION: Fatty-liver creates an inflammatory state which adversely affects the outcome of autologous islet cell transplantation.


Assuntos
Diabetes Mellitus Experimental/terapia , Sobrevivência de Enxerto , Transplante das Ilhotas Pancreáticas/efeitos adversos , Fígado/patologia , Hepatopatia Gordurosa não Alcoólica/complicações , Animais , Biomarcadores/sangue , Biomarcadores/metabolismo , Glicemia/análise , Diabetes Mellitus Experimental/sangue , Diabetes Mellitus Experimental/complicações , Diabetes Mellitus Experimental/imunologia , Dieta Hiperlipídica/efeitos adversos , Hiperglicemia/prevenção & controle , Imuno-Histoquímica , Interleucina-1beta/genética , Interleucina-1beta/metabolismo , Transplante das Ilhotas Pancreáticas/imunologia , Transplante das Ilhotas Pancreáticas/patologia , Masculino , Camundongos Endogâmicos C57BL , Hepatopatia Gordurosa não Alcoólica/imunologia , Hepatopatia Gordurosa não Alcoólica/metabolismo , Hepatopatia Gordurosa não Alcoólica/patologia , Projetos Piloto , Análise de Componente Principal , Transplante Autólogo/efeitos adversos , Transplante Heterotópico/efeitos adversos , Transplante Isogênico/efeitos adversos , Fator de Necrose Tumoral alfa/metabolismo
20.
Zootaxa ; 4250(2): 171-185, 2017 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-28610025

RESUMO

A new species, Gracixalus jinggangensis sp. nov., is described based on a series of specimens collected from Mount Jinggang, Jiangxi Province, southeastern China. The new species is distinguished from all other known congeners by the following combination of morphological characters: relatively small body size, SVL 27.9-33.8 mm in nine males and 31.6 mm in a single female; upper eyelid and dorsum lacking spines; skin of dorsal and lateral surface of head, body and limbs rough with sparsely scattered with tubercles; ventral skin granular; tibiotarsal projection absent; finger webbing rudimentary; toes with moderately developed webbing; brown to beige above in life, with an inverse Y-shaped dark brown marking extending from the interorbital region to the middle of dorsum; males with a single, subgular vocal sac, barely visible nuptial pads with minute granules on the dorsal surface of the bases of first and second fingers. The new species is also genetically divergent from all other Gracixalus for which comparable 16S rRNA gene sequences are available. The discovery of Gracixalus jinggangensis sp. nov. represents the twelfth known species in the genus.


Assuntos
Anuros , Animais , Tamanho Corporal , China , Feminino , Masculino , Filogenia , RNA Ribossômico 16S
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...