Agro-ecological conditions associated with the spread and persistence of highly pathogenic avian inlfuenza （HPAI） are not well understood, but the trade of live poultry is suspected to be a major pathway. Although m...Agro-ecological conditions associated with the spread and persistence of highly pathogenic avian inlfuenza （HPAI） are not well understood, but the trade of live poultry is suspected to be a major pathway. Although market chains of live bird trade have been studied through indirect means including interviews and questionnaires, direct methods have not been used to identify movements of individual poultry. To bridge the knowledge gap on quantitative movement and transportation of poultry, we introduced a novel approach for applying telemetry to document domestic duck movements from source farms at Poyang Lake, China. We deployed recently developed transmitters that record Global Positioning System （GPS） locations and send them through the Groupe Spécial Mobile （GSM） cellular telephone system. For the ifrst time, we were able to track individually marked ducks from 3 to 396 km from their origin to other farms, distribution facilities, or live bird markets. Our proof of concept test showed that the use of GPS-GSM transmitters may provide di-rect, quantitative information to document the movement of poultry and reveal their market chains. Our ifndings provide an initial indication of the complexity of source-market network connectivity and highlight the great potential for future telemetry studies in poultry network analyses.展开更多
Hypoxia-inducible factor 1 alpha（HIF-1α） and its target genes vascular endothelial growth factor（VEGF） and transferrins（TF） play an important role in native endothermic animals＇ adaptation to the high altitude...Hypoxia-inducible factor 1 alpha（HIF-1α） and its target genes vascular endothelial growth factor（VEGF） and transferrins（TF） play an important role in native endothermic animals＇ adaptation to the high altitude environments. For ectothermic animals – especially frogs – it remains undetermined whether HIF-1α and its target genes（VEGF and TF） play an important role in high altitude adaptation, too. In this study, we compared the gene sequences and expression of HIF-1α and its target genes（VEGF and TF） between three Nanorana parkeri populations from different altitudes（3008 m a.s.l., 3440 m a.s.l. and 4312 m a.s.l.）. We observed that the c DNA sequences of HIF-1A exhibited high sequence similarity（99.38%） among the three altitudinally separated populations; but with increasing altitude, the expression of HIF-1A and its target genes（VEGF and TF） increased significantly. These results indicate that HIF-1α plays an important role in N. parkeri adaptation to the high altitude, similar to its role in endothermic animals.展开更多
Brood parasites,such as the Common Cuckoo(Cuculus canorus),rely on manipulating hosts from other species to raise their offspring.Selection should favor individuals that are able to identify and choose host nests that...Brood parasites,such as the Common Cuckoo(Cuculus canorus),rely on manipulating hosts from other species to raise their offspring.Selection should favor individuals that are able to identify and choose host nests that closely match the incubation stage of their own eggs.While intuitive,and supported by the findings of numerous longterm monitoring studies,experimental evidence of this remains sparse.By using video monitoring,we used three experimental groups to explore whether Common Cuckoos preferentially choose host Oriental Reed Warbler(Acrocephalus orientalis)nests that are early in their laying cycle.We found that Common Cuckoos preferentially parasitize nests of the host Oriental Reed Warbler that are earlier in their laying(less vs.more eggs)or nesting cycle(eggs vs.chicks),and videos of our experiments provide direct insights into their decision making process.Our results provide strong experimental evidence that Common Cuckoos are able to assess nesting stage and strategically choose nests that increase the likelihood of successful parasitism.展开更多
For species that have a broad geographic distribution, adaptive variation may be attributable to gene expression plasticity. Nanorana parkeri is an anuran endemic to the southern Tibetan Plateau where it has an extens...For species that have a broad geographic distribution, adaptive variation may be attributable to gene expression plasticity. Nanorana parkeri is an anuran endemic to the southern Tibetan Plateau where it has an extensive altitudinal range（2850 to 5100 m asl）. Low oxygen concentration is one of the main environmental characteristics of the Tibetan Plateau. Hypoxia-inducible factor α subunits（HIF-1α and HIF-2α, encoded by Endothelial PAS domain protein 1（EPAS1）） and associated genes（e.g., vascular endothelial growth factor（VEGF） and Erythropoietin（EPO）） play crucial roles in maintaining oxygen homeostasis. In this study, we compared the expression of HIF-1A, VEGF, EPAS1 and EPO mRNA between two populations of N. parkeri： one population inhabiting the native high altitudes, and the second living in, and being acclimated to, the lower plains（70 m asl）. The expression of HIF-1A, VEGF and EPAS1 mRNA in the high altitude population were significantly higher than in the acclimated population, whereas there was no significant difference for EPO between two groups. Our results indicated that gene expression plasticity may make significant contributions to local adaptation of species that have broad altitudinal distributions. In addition, we deepen our understanding of the adaptive potential of this species by evaluating the experiments in the scope of its evolutionary history.展开更多
Introgression,the incorporation of genetic material from one(sub)species into the gene pool of another by means of hybridization and backcrossing,is a common phenomenon in birds and can provide important insights into...Introgression,the incorporation of genetic material from one(sub)species into the gene pool of another by means of hybridization and backcrossing,is a common phenomenon in birds and can provide important insights into the speciation process.In the last decade,the toolkit for studying introgression has expanded together with the development of molecular markers.In this review,we explore how genomic data,the most recent step in this methodological progress,impacts different aspects in the study of avian introgression.First,the detection of hybrids and backcrosses has improved dramatically.The most widely used software package is STRUCTURE.Phylogenetic discordance(i.e.different loci resulting in discordant gene trees) is another means for the detection of introgression,although it should be regarded as a starting point for further analyses,not as a definitive proof of introgression.Specifically,disentangling introgression from other biological processes,such as incomplete lineage sorting,remains a challenging endeavour,although new techniques,such as the D-statistic,are being developed.In addition,phylogenetics might require a shift from trees to networks.Second,the study of hybrid zones by means of geographical or genomic cline analysis has led to important insights into the complex interplay between hybridization and speciation.However,because each hybrid zone study is just a single snapshot of a complex and continuously changing interaction,hybrid zones should be studied across different temporal and/or spatial scales.A third powerful tool is the genome scan.The debate on which evolutionary processes underlie the genomic landscape is still ongoing,as is the question whether loci involved in reproductive isolation cluster together in ‘islands of speciation' or whether they are scattered throughout the genome.Exploring genomic landscapes across the avian tree of life will be an exciting field for further research.Finally,the findings from these different methods should be incorporated into specific speciation scenarios,which can consequently be tested using a modelling approach.All in all,this genomic perspective on avian hybridization and speciation will further our understanding in evolution in general.展开更多
The Galápagos are considered a model oceanic archipelago,with unique flora and fauna currently threatened by alien invasive species.Seed dispersal is an important ecosystem function with consequences for plant po...The Galápagos are considered a model oceanic archipelago,with unique flora and fauna currently threatened by alien invasive species.Seed dispersal is an important ecosystem function with consequences for plant population dynamics and vegetation structure.Hence,understanding the seed dispersal abilities of the assemblages of frugivores will inform scientists and managers of the dynamics of plant invasions and improve management planning.Here we provide the first comprehensive review of published information on frugivory and animal seed dispersal in the Galápagos.We collected data from a variety of sources,including notes of the first naturalist expeditions,gray literature available only in Galápagos collections,and peer-reviewed journal articles.Plant–animal frugivorous interactions were retrieved from 43 studies and compiled into an interaction matrix describing 366 unique interactions.Most studies focused on fruit consumption as a driving force for natural selection,but seed fate was seldom considered.Although most(71%)of the interactions involved native plants,more than one-quarter(28%)involved introduced species.Interactions involving birds are considerably more common than those of reptiles and mammals,probably reflecting a research bias towards birds.Despite the historical importance of the archipelago as the laboratory for evolutionary and ecological research,understanding of its seed dispersal systems is limited.We end the review by suggesting 3 priority areas of research on frugivory and seed dispersal in the Galápagos:(i)target research to close knowledge gaps;(ii)the use of a network approach to frame seed dispersal at the community level;and(iii)evaluation of the effect of seed dispersal as a selective pressure acting upon plants and frugivores.Finally,the output of this research has to be properly delivered to the Galápagos National Park Services to help increase management effectiveness.展开更多
基金supported by the grants from the National Institutes of Health(1R01AI101028-01A1)the Office of Health,Infectious Diseases and Nutrition in the Bureau for Global Health,U.S.Agency for International Development(GHA-G-00-06-00001)
文摘Agro-ecological conditions associated with the spread and persistence of highly pathogenic avian inlfuenza （HPAI） are not well understood, but the trade of live poultry is suspected to be a major pathway. Although market chains of live bird trade have been studied through indirect means including interviews and questionnaires, direct methods have not been used to identify movements of individual poultry. To bridge the knowledge gap on quantitative movement and transportation of poultry, we introduced a novel approach for applying telemetry to document domestic duck movements from source farms at Poyang Lake, China. We deployed recently developed transmitters that record Global Positioning System （GPS） locations and send them through the Groupe Spécial Mobile （GSM） cellular telephone system. For the ifrst time, we were able to track individually marked ducks from 3 to 396 km from their origin to other farms, distribution facilities, or live bird markets. Our proof of concept test showed that the use of GPS-GSM transmitters may provide di-rect, quantitative information to document the movement of poultry and reveal their market chains. Our ifndings provide an initial indication of the complexity of source-market network connectivity and highlight the great potential for future telemetry studies in poultry network analyses.
基金supported by National Natural Science Foundation of China(No.31471994)
文摘Hypoxia-inducible factor 1 alpha（HIF-1α） and its target genes vascular endothelial growth factor（VEGF） and transferrins（TF） play an important role in native endothermic animals＇ adaptation to the high altitude environments. For ectothermic animals – especially frogs – it remains undetermined whether HIF-1α and its target genes（VEGF and TF） play an important role in high altitude adaptation, too. In this study, we compared the gene sequences and expression of HIF-1α and its target genes（VEGF and TF） between three Nanorana parkeri populations from different altitudes（3008 m a.s.l., 3440 m a.s.l. and 4312 m a.s.l.）. We observed that the c DNA sequences of HIF-1A exhibited high sequence similarity（99.38%） among the three altitudinally separated populations; but with increasing altitude, the expression of HIF-1A and its target genes（VEGF and TF） increased significantly. These results indicate that HIF-1α plays an important role in N. parkeri adaptation to the high altitude, similar to its role in endothermic animals.
基金supported by the National Natural Science Foundation of China(Nos.31960105 to LW,and 31970427 to WL)the specific research fund of the Innovation Platform for Academicians of Hainan Provincefunded by the Guizhou Natural Science Foundation(No.ZK[2022]-316)。
文摘Brood parasites,such as the Common Cuckoo(Cuculus canorus),rely on manipulating hosts from other species to raise their offspring.Selection should favor individuals that are able to identify and choose host nests that closely match the incubation stage of their own eggs.While intuitive,and supported by the findings of numerous longterm monitoring studies,experimental evidence of this remains sparse.By using video monitoring,we used three experimental groups to explore whether Common Cuckoos preferentially choose host Oriental Reed Warbler(Acrocephalus orientalis)nests that are early in their laying cycle.We found that Common Cuckoos preferentially parasitize nests of the host Oriental Reed Warbler that are earlier in their laying(less vs.more eggs)or nesting cycle(eggs vs.chicks),and videos of our experiments provide direct insights into their decision making process.Our results provide strong experimental evidence that Common Cuckoos are able to assess nesting stage and strategically choose nests that increase the likelihood of successful parasitism.
基金supported by National Natural Science Foundation of China(No.31471994)
文摘For species that have a broad geographic distribution, adaptive variation may be attributable to gene expression plasticity. Nanorana parkeri is an anuran endemic to the southern Tibetan Plateau where it has an extensive altitudinal range（2850 to 5100 m asl）. Low oxygen concentration is one of the main environmental characteristics of the Tibetan Plateau. Hypoxia-inducible factor α subunits（HIF-1α and HIF-2α, encoded by Endothelial PAS domain protein 1（EPAS1）） and associated genes（e.g., vascular endothelial growth factor（VEGF） and Erythropoietin（EPO）） play crucial roles in maintaining oxygen homeostasis. In this study, we compared the expression of HIF-1A, VEGF, EPAS1 and EPO mRNA between two populations of N. parkeri： one population inhabiting the native high altitudes, and the second living in, and being acclimated to, the lower plains（70 m asl）. The expression of HIF-1A, VEGF and EPAS1 mRNA in the high altitude population were significantly higher than in the acclimated population, whereas there was no significant difference for EPO between two groups. Our results indicated that gene expression plasticity may make significant contributions to local adaptation of species that have broad altitudinal distributions. In addition, we deepen our understanding of the adaptive potential of this species by evaluating the experiments in the scope of its evolutionary history.
文摘Introgression,the incorporation of genetic material from one(sub)species into the gene pool of another by means of hybridization and backcrossing,is a common phenomenon in birds and can provide important insights into the speciation process.In the last decade,the toolkit for studying introgression has expanded together with the development of molecular markers.In this review,we explore how genomic data,the most recent step in this methodological progress,impacts different aspects in the study of avian introgression.First,the detection of hybrids and backcrosses has improved dramatically.The most widely used software package is STRUCTURE.Phylogenetic discordance(i.e.different loci resulting in discordant gene trees) is another means for the detection of introgression,although it should be regarded as a starting point for further analyses,not as a definitive proof of introgression.Specifically,disentangling introgression from other biological processes,such as incomplete lineage sorting,remains a challenging endeavour,although new techniques,such as the D-statistic,are being developed.In addition,phylogenetics might require a shift from trees to networks.Second,the study of hybrid zones by means of geographical or genomic cline analysis has led to important insights into the complex interplay between hybridization and speciation.However,because each hybrid zone study is just a single snapshot of a complex and continuously changing interaction,hybrid zones should be studied across different temporal and/or spatial scales.A third powerful tool is the genome scan.The debate on which evolutionary processes underlie the genomic landscape is still ongoing,as is the question whether loci involved in reproductive isolation cluster together in ‘islands of speciation' or whether they are scattered throughout the genome.Exploring genomic landscapes across the avian tree of life will be an exciting field for further research.Finally,the findings from these different methods should be incorporated into specific speciation scenarios,which can consequently be tested using a modelling approach.All in all,this genomic perspective on avian hybridization and speciation will further our understanding in evolution in general.
基金The present study was part of a biodiversity project funded by the BBVA Foundation(Spain).
文摘The Galápagos are considered a model oceanic archipelago,with unique flora and fauna currently threatened by alien invasive species.Seed dispersal is an important ecosystem function with consequences for plant population dynamics and vegetation structure.Hence,understanding the seed dispersal abilities of the assemblages of frugivores will inform scientists and managers of the dynamics of plant invasions and improve management planning.Here we provide the first comprehensive review of published information on frugivory and animal seed dispersal in the Galápagos.We collected data from a variety of sources,including notes of the first naturalist expeditions,gray literature available only in Galápagos collections,and peer-reviewed journal articles.Plant–animal frugivorous interactions were retrieved from 43 studies and compiled into an interaction matrix describing 366 unique interactions.Most studies focused on fruit consumption as a driving force for natural selection,but seed fate was seldom considered.Although most(71%)of the interactions involved native plants,more than one-quarter(28%)involved introduced species.Interactions involving birds are considerably more common than those of reptiles and mammals,probably reflecting a research bias towards birds.Despite the historical importance of the archipelago as the laboratory for evolutionary and ecological research,understanding of its seed dispersal systems is limited.We end the review by suggesting 3 priority areas of research on frugivory and seed dispersal in the Galápagos:(i)target research to close knowledge gaps;(ii)the use of a network approach to frame seed dispersal at the community level;and(iii)evaluation of the effect of seed dispersal as a selective pressure acting upon plants and frugivores.Finally,the output of this research has to be properly delivered to the Galápagos National Park Services to help increase management effectiveness.
