The leaf muntjac （Muntiacus putaoensis） is an endemic deer species found in the east trans- Himalayan region. In recent years, population numbers have decreased due to heavy hunting and habitat loss, and little gene...The leaf muntjac （Muntiacus putaoensis） is an endemic deer species found in the east trans- Himalayan region. In recent years, population numbers have decreased due to heavy hunting and habitat loss, and little genetic data exists for this species, thus our knowledge of distribution rangs and population sizes likewise remain limited. We obtained mtDNA genes and the complete mitochondrial genome sequence of M. putaoensis using PCR, followed by direct sequencing. The complete mitogenome sequence was determined as a circular 16 349 bp mitochondrial genome, containing 13 protein-coding genes, two rRNA genes 22 tRNA genes, and one control region, the gene composition and order of which were similar to most other vertebrates so far reported. Most mitochondrial genes, except for ND6 and eight tRNAs, were encoded on the heavy strand. The overall base composition of the heavy strand was 33.1% A, 29.3% T, 24.2% C, and 13.4% G, with a strong AT bias of 62.4%. There were seven regions of gene overlap totaling 95 bp and 11 intergenic spacer regions totaling 74 bp. Phylogenetic analyses （ML and BI） among the Muntiacus genus based on the sequenced of mitogenome and ND4L-ND4 supported M. putaoensis as a member of Muntiacus, most closely related to M. vuquangensis. However, when analyses based on cyt b included two more muntjacs, M. truongsonensis was most closely related to M. putaoensis rather than M. vuquangensis, and together with M. rooseveltorum, likely forming a M. rooseveltorum complex of the species. This study will help in the exploration of the evolutionary history and taxonomic status of the leaf muntjac, as well as its protection as a genetic resource.展开更多
Dengue virus(DENV)is one of the most important arboviral pathogens in the tropics and subtropics,and nearly one-third of the world's population is at risk of infection.The transmission of DENV involves a sylvatic ...Dengue virus(DENV)is one of the most important arboviral pathogens in the tropics and subtropics,and nearly one-third of the world's population is at risk of infection.The transmission of DENV involves a sylvatic cycle between nonhuman primates(NHP)and Aedes genus mosquitoes,and an endemic cycle between human hosts and predominantly Aedes aegypti.DENV belongs to the genus Flavivirus of the family Flaviviridae and consists of four antigenically distinct serotypes(DENV-1-4).Phylogenetic analyses of DENV have revealed its origin,epidemiology,and the drivers that determine its molecular evolution in nature.This review discusses how phyloge-netic research has improved our understanding of DENV evolution and how it affects viral ecology and improved our ability to analyze and predict future DENV emergence.展开更多
Understanding the level of genetic diversity in any population is an important requisite towards strategizing measures for conservation and improvement of stocks. This study focused on the assessment of phylogenetics ...Understanding the level of genetic diversity in any population is an important requisite towards strategizing measures for conservation and improvement of stocks. This study focused on the assessment of phylogenetics and molecular divergence of tilapia fish species obtained from two populations (Domita in South-South and Odeda in South-West, Nigeria) using the displacement loop (D-loop) and cytochrome b region of the mitochondrial deoxyribonucleic acid (mtDNA). A total of 28 samples (15 from South-South and 13 from South-West) were used for the genetic analysis. DNA was extracted from the tissue of all the samples using Quik-gDNATM miniPrep kit. The D-loop containing the hypervariable region was sequenced for all samples from the two populations, while cytochrome b (Cyt b) region of mtDNA was only sequenced for samples from South-South population. Chromatograms of the sequences were viewed and edited using Bioedit software. Multiple sequence alignment was carried out using molecular evolutionary genetic analysis (MEGA) software before subsequent genetic analyses. Phylogenetic analysis grouped the samples into two clusters based on population. Also, when the two mitochondrial regions were pooled together, they clustered into two major groups based on mitochondrial regions. Analysis of molecular variance (AMOVA) revealed 37.32% variation within population and 62.68% variation among population with a significant fixation index of 0.627 (p 0.05). The genetic distance inferred between D-loop regions of South-South and South-West populations was 0.243. Maternal lineage analysis revealed that the origin of tilapia fish from both populations could be traced to Oreochromis spirilus and Oreochromis leucostictus based on mitochondrial D-loop region. The findings of this study revealed molecular divergence among the tilapia populations and may serve as pivot information for the genetic improvement of this important species.展开更多
The effect of missing data on phylogenetic methods is a potentially important issue in our attempts to reconstruct the Tree of Life. If missing data are truly problematic, then it may be unwise to include species in a...The effect of missing data on phylogenetic methods is a potentially important issue in our attempts to reconstruct the Tree of Life. If missing data are truly problematic, then it may be unwise to include species in an analysis that lack data for some characters (incomplete taxa) or to include characters that lack data for some species. Given the difficulty of obtaining data from all characters for all taxa (e.g., fossils), missing data might seriously impede efforts to reconstruct a comprehensive phylogeny that includes all species. Fortunately, recent simulations and empirical analyses suggest that missing data cells are not themselves problematic, and that in-complete taxa can be accurately placed as long as the overall number of characters in the analysis is large. How-ever, these studies have so far only been conducted on parsimony, likelihood, and neighbor-joining methods. Although Bayesian phylogenetic methods have become widely used in recent years, the effects of missing data on Bayesian analysis have not been adequately studied. Here, we conduct simulations to test whether Bayesian analyses can accurately place incomplete taxa despite extensive missing data. In agreement with previous studies of other methods, we find that Bayesian analyses can accurately reconstruct the position of highly incomplete taxa (i.e., 95% missing data), as long as the overall number of characters in the analysis is large. These results suggest that highly incomplete taxa can be safely included in many Bayesian phylogenetic analyses.展开更多
基金supported by a grant from the Southeast Asia Biodiversity Research Institute,Chinese Academy of Sciences(Y4ZK111B01)
文摘The leaf muntjac （Muntiacus putaoensis） is an endemic deer species found in the east trans- Himalayan region. In recent years, population numbers have decreased due to heavy hunting and habitat loss, and little genetic data exists for this species, thus our knowledge of distribution rangs and population sizes likewise remain limited. We obtained mtDNA genes and the complete mitochondrial genome sequence of M. putaoensis using PCR, followed by direct sequencing. The complete mitogenome sequence was determined as a circular 16 349 bp mitochondrial genome, containing 13 protein-coding genes, two rRNA genes 22 tRNA genes, and one control region, the gene composition and order of which were similar to most other vertebrates so far reported. Most mitochondrial genes, except for ND6 and eight tRNAs, were encoded on the heavy strand. The overall base composition of the heavy strand was 33.1% A, 29.3% T, 24.2% C, and 13.4% G, with a strong AT bias of 62.4%. There were seven regions of gene overlap totaling 95 bp and 11 intergenic spacer regions totaling 74 bp. Phylogenetic analyses （ML and BI） among the Muntiacus genus based on the sequenced of mitogenome and ND4L-ND4 supported M. putaoensis as a member of Muntiacus, most closely related to M. vuquangensis. However, when analyses based on cyt b included two more muntjacs, M. truongsonensis was most closely related to M. putaoensis rather than M. vuquangensis, and together with M. rooseveltorum, likely forming a M. rooseveltorum complex of the species. This study will help in the exploration of the evolutionary history and taxonomic status of the leaf muntjac, as well as its protection as a genetic resource.
基金National Key Research and Development Plan of China,Grant/Award Number:2018YFA0507202,2020YFC1200100 and 2021YFC2300200National Natural Science Foundation of China,Grant/Award Number:31825001,32188101,81730063,81961160737 and 82102389+5 种基金Provincial Innovation Team for the Prevention and Control of Highly Pathogenic Pathogens,Institute of Medical Biology,Chinese Academy of Medical Sciences,Grant/Award Number:202105AE160020Shenzhen San-Ming Project for Prevention and Research on Vector-borne Diseases,Grant/Award Number:SZSM201611064Shenzhen Science and Technology Project,Grant/Award Number:JSGG20191129144225464Tsinghua University Spring Breeze Fund,Grant/Award Number:2020Z99CFG017Young Elite Scientists Sponsorship Program,Grant/Award Number:2021QNRC001Yunnan Cheng Gong Expert Work-Station,Grant/Award Number:202005AF150034。
文摘Dengue virus(DENV)is one of the most important arboviral pathogens in the tropics and subtropics,and nearly one-third of the world's population is at risk of infection.The transmission of DENV involves a sylvatic cycle between nonhuman primates(NHP)and Aedes genus mosquitoes,and an endemic cycle between human hosts and predominantly Aedes aegypti.DENV belongs to the genus Flavivirus of the family Flaviviridae and consists of four antigenically distinct serotypes(DENV-1-4).Phylogenetic analyses of DENV have revealed its origin,epidemiology,and the drivers that determine its molecular evolution in nature.This review discusses how phyloge-netic research has improved our understanding of DENV evolution and how it affects viral ecology and improved our ability to analyze and predict future DENV emergence.
文摘Understanding the level of genetic diversity in any population is an important requisite towards strategizing measures for conservation and improvement of stocks. This study focused on the assessment of phylogenetics and molecular divergence of tilapia fish species obtained from two populations (Domita in South-South and Odeda in South-West, Nigeria) using the displacement loop (D-loop) and cytochrome b region of the mitochondrial deoxyribonucleic acid (mtDNA). A total of 28 samples (15 from South-South and 13 from South-West) were used for the genetic analysis. DNA was extracted from the tissue of all the samples using Quik-gDNATM miniPrep kit. The D-loop containing the hypervariable region was sequenced for all samples from the two populations, while cytochrome b (Cyt b) region of mtDNA was only sequenced for samples from South-South population. Chromatograms of the sequences were viewed and edited using Bioedit software. Multiple sequence alignment was carried out using molecular evolutionary genetic analysis (MEGA) software before subsequent genetic analyses. Phylogenetic analysis grouped the samples into two clusters based on population. Also, when the two mitochondrial regions were pooled together, they clustered into two major groups based on mitochondrial regions. Analysis of molecular variance (AMOVA) revealed 37.32% variation within population and 62.68% variation among population with a significant fixation index of 0.627 (p 0.05). The genetic distance inferred between D-loop regions of South-South and South-West populations was 0.243. Maternal lineage analysis revealed that the origin of tilapia fish from both populations could be traced to Oreochromis spirilus and Oreochromis leucostictus based on mitochondrial D-loop region. The findings of this study revealed molecular divergence among the tilapia populations and may serve as pivot information for the genetic improvement of this important species.
文摘The effect of missing data on phylogenetic methods is a potentially important issue in our attempts to reconstruct the Tree of Life. If missing data are truly problematic, then it may be unwise to include species in an analysis that lack data for some characters (incomplete taxa) or to include characters that lack data for some species. Given the difficulty of obtaining data from all characters for all taxa (e.g., fossils), missing data might seriously impede efforts to reconstruct a comprehensive phylogeny that includes all species. Fortunately, recent simulations and empirical analyses suggest that missing data cells are not themselves problematic, and that in-complete taxa can be accurately placed as long as the overall number of characters in the analysis is large. How-ever, these studies have so far only been conducted on parsimony, likelihood, and neighbor-joining methods. Although Bayesian phylogenetic methods have become widely used in recent years, the effects of missing data on Bayesian analysis have not been adequately studied. Here, we conduct simulations to test whether Bayesian analyses can accurately place incomplete taxa despite extensive missing data. In agreement with previous studies of other methods, we find that Bayesian analyses can accurately reconstruct the position of highly incomplete taxa (i.e., 95% missing data), as long as the overall number of characters in the analysis is large. These results suggest that highly incomplete taxa can be safely included in many Bayesian phylogenetic analyses.
