The phylogenetic relationships of four species,Bufo melanostictus,Hyla chinensis,Rana limnocharis and Rana guentheri,which belong to three differrent families of Anura,were detected with RAPD technique.The genomic DNA...The phylogenetic relationships of four species,Bufo melanostictus,Hyla chinensis,Rana limnocharis and Rana guentheri,which belong to three differrent families of Anura,were detected with RAPD technique.The genomic DNA of each species was amplified with 19 random primers.16 primers given clear amplified bands were used for analysis and the genetic distances between four species were calculated.The results show that RAPD bands obtained by all 16 primers evinced different degree polymorphisms.The genetic distance between R.limnocharis and R.guentheri is the nearest,that between B.melanostictus and H.chinensis is the second nearest,and that between B.melanostictus and R.guentheri is the furthest.The different distances also indicated that the relationship between Bufoidae and Hylidae is closer than that between Bufonidae and Ranidae at genomic DNA level.In concordant with the conclusion of the morphology,chromosomal and mitochondrial DNA studies,our results provide a new evidence of the systematic evolution of the three families of Anura at DNA molecular level.展开更多
MicroRNAs （miRNAs） are important post-transcriptional regulators of their target genes in plants and animals, miRNAs are usually 20-24 nucleotides long. Despite their unusually small sizes, the evolutionary history ...MicroRNAs （miRNAs） are important post-transcriptional regulators of their target genes in plants and animals, miRNAs are usually 20-24 nucleotides long. Despite their unusually small sizes, the evolutionary history of miRNA gene families seems to be similar to their protein-codingcounterparts. In contrast to the small but abundant miRNA families in the animal genomes, plants have fewer but larger miRNA gene families. Members of plant miRNA gene families are often highly similar, suggesting recent expansion via tandem gene duplication and segmental duplication events. Although many miRNA genes are conserved across plant species, the same gene family varies significantly in size and genomic organization in different species, which may cause dosage effects and spatial and temporal differences in target gene regulations. In this review, we summarize the current progress in understanding the evolution of plant miRNA gene families.展开更多
A molecular phylogenetic analysis of the genus Scomber was conducted based on mitochondrial(COI,Cyt b and control region) and nuclear(5S rDNA) DNA sequence data in multigene perspective.A variety of phylogenetic analy...A molecular phylogenetic analysis of the genus Scomber was conducted based on mitochondrial(COI,Cyt b and control region) and nuclear(5S rDNA) DNA sequence data in multigene perspective.A variety of phylogenetic analytic methods were used to clarify the current taxonomic classification and to assess phylogenetic relationships and the evolutionary history of this genus.The present study produced a well-resolved phylogeny that strongly supported the monophyly of Scomber.We confirmed that S.japonicus and S.colias were genetically distinct.Although morphologically and ecologically similar to S.colias,the molecular data showed that S.japonicus has a greater molecular affinity with S.australasicus,which conflicts with the traditional taxonomy.This phylogenetic pattern was corroborated by the mtDNA data,but incompletely by the nuclear DNA data.Phylogenetic concordance between the mitochondrial and nuclear DNA regions for the basal nodes supports an Atlantic origin for Scomber.The present-day geographic ranges of the species were compared with the resultant molecular phylogeny derived from partition Bayesian analyses of the combined data sets to evaluate possible dispersal routes of the genus.The present-day geographic distribution of Scomber species might be best ascribed to multiple dispersal events.In addition,our results suggest that phylogenies derived from multiple genes and long sequences exhibited improved phylogenetic resolution,from which we conclude that the phylogenetic reconstruction is a reliable representation of the evolutionary history of Scomber.展开更多
Sequencing technology has developed rapidly in recent years. Complete or nearly complete mitochondrial genomes(mitogenomes) of 155 species from 47 families in Heteroptera have been sequenced. However, the amounts of m...Sequencing technology has developed rapidly in recent years. Complete or nearly complete mitochondrial genomes(mitogenomes) of 155 species from 47 families in Heteroptera have been sequenced. However, the amounts of mitogenomes between those families are unbalanced, which makes it difficult to correctly discern the patterns of mitogenome rearrangement in Heteroptera. Among 21 species from ten families, ten variations in mitogenome rearrangement had been previously reported, among which the translocation between tRNA-Thr and tRNA-Pro was considered as a synapomorphy of Pyrrhocoroidea based on two mitogenomes. As only one mitogenome in each of Largidae and Pyrrhocoridae had been sequenced to conclude the synapomorphy, more mitogenomes of Pyrrhocoroidea need to be explored. In this study, additional two mitogenomes of Pyrrhocoroidea(Macrocheraia grandis grandis(Gray, 1832) and Myrmoplasta mira Gerst-cker, 1892) were sequenced. Both of them also possess the same translocation between tRNA-Thr and tRNA-Pro, which reaffirms that this kind of rearrangement is a molecular synapomorphy of Pyrrhocoroidea. Moreover, we discovered a more complex rearrangement in Myrmoplasta mira, in which six nearly identical duplications of tRNA-Thr were found located downstream of tRNA-Pro. Considering the high biodiversity of Heteroptera, more mitogenomic studies are needed to improve our knowledge about mitogenome rearrangements and the potential synapomorphies.展开更多
Scallops of the Family Pectinidae are a valuable resource in marine industry of the world. Understanding the phylogeny of the family is important for the development of the industry. In this study, partial 16S mitocho...Scallops of the Family Pectinidae are a valuable resource in marine industry of the world. Understanding the phylogeny of the family is important for the development of the industry. In this study, partial 16S mitochondrial rDNA genes were obtained from 8 scallop species that are commonly cultured indigenous and transplanted species in China. Phylogenetic relationships of Pectinidae were analyzed based on the 8 sequences and other 5 published ones in GenBank, representing 9 genera of the family. The molecular phylogeny trees were constructed using 3 methods with software PHYLIP. The results showe that total 13 species of scallops clustered in 4 clades. Pecten maximus joins P. jacobaeus then Amusium pleuronectes in cluster, indicating close relationship of genus Amusium with Pecten in evolution. P. yes- soensis is close to Chlamys farreri and C. islandica. No enough material was available to single out genus Patinopecten as an independent monophyletic subfamily. The position of Adamussium colbecki indicates that it is far from genus Pecten but near to genus Chlamys in evolution.展开更多
文摘The phylogenetic relationships of four species,Bufo melanostictus,Hyla chinensis,Rana limnocharis and Rana guentheri,which belong to three differrent families of Anura,were detected with RAPD technique.The genomic DNA of each species was amplified with 19 random primers.16 primers given clear amplified bands were used for analysis and the genetic distances between four species were calculated.The results show that RAPD bands obtained by all 16 primers evinced different degree polymorphisms.The genetic distance between R.limnocharis and R.guentheri is the nearest,that between B.melanostictus and H.chinensis is the second nearest,and that between B.melanostictus and R.guentheri is the furthest.The different distances also indicated that the relationship between Bufoidae and Hylidae is closer than that between Bufonidae and Ranidae at genomic DNA level.In concordant with the conclusion of the morphology,chromosomal and mitochondrial DNA studies,our results provide a new evidence of the systematic evolution of the three families of Anura at DNA molecular level.
文摘MicroRNAs （miRNAs） are important post-transcriptional regulators of their target genes in plants and animals, miRNAs are usually 20-24 nucleotides long. Despite their unusually small sizes, the evolutionary history of miRNA gene families seems to be similar to their protein-codingcounterparts. In contrast to the small but abundant miRNA families in the animal genomes, plants have fewer but larger miRNA gene families. Members of plant miRNA gene families are often highly similar, suggesting recent expansion via tandem gene duplication and segmental duplication events. Although many miRNA genes are conserved across plant species, the same gene family varies significantly in size and genomic organization in different species, which may cause dosage effects and spatial and temporal differences in target gene regulations. In this review, we summarize the current progress in understanding the evolution of plant miRNA gene families.
基金Supported by the International Cooperation and Exchange of the National Natural Science Foundation of China (No. 31061160187)Special Fund for Agro-scientific Research in the Public Interest(No. 200903005)
文摘A molecular phylogenetic analysis of the genus Scomber was conducted based on mitochondrial(COI,Cyt b and control region) and nuclear(5S rDNA) DNA sequence data in multigene perspective.A variety of phylogenetic analytic methods were used to clarify the current taxonomic classification and to assess phylogenetic relationships and the evolutionary history of this genus.The present study produced a well-resolved phylogeny that strongly supported the monophyly of Scomber.We confirmed that S.japonicus and S.colias were genetically distinct.Although morphologically and ecologically similar to S.colias,the molecular data showed that S.japonicus has a greater molecular affinity with S.australasicus,which conflicts with the traditional taxonomy.This phylogenetic pattern was corroborated by the mtDNA data,but incompletely by the nuclear DNA data.Phylogenetic concordance between the mitochondrial and nuclear DNA regions for the basal nodes supports an Atlantic origin for Scomber.The present-day geographic ranges of the species were compared with the resultant molecular phylogeny derived from partition Bayesian analyses of the combined data sets to evaluate possible dispersal routes of the genus.The present-day geographic distribution of Scomber species might be best ascribed to multiple dispersal events.In addition,our results suggest that phylogenies derived from multiple genes and long sequences exhibited improved phylogenetic resolution,from which we conclude that the phylogenetic reconstruction is a reliable representation of the evolutionary history of Scomber.
基金financially supported by the Ministry of Culture of the Czech Republic(DKRVO 2019/5.I.a,National Museum,00023272)
文摘Sequencing technology has developed rapidly in recent years. Complete or nearly complete mitochondrial genomes(mitogenomes) of 155 species from 47 families in Heteroptera have been sequenced. However, the amounts of mitogenomes between those families are unbalanced, which makes it difficult to correctly discern the patterns of mitogenome rearrangement in Heteroptera. Among 21 species from ten families, ten variations in mitogenome rearrangement had been previously reported, among which the translocation between tRNA-Thr and tRNA-Pro was considered as a synapomorphy of Pyrrhocoroidea based on two mitogenomes. As only one mitogenome in each of Largidae and Pyrrhocoridae had been sequenced to conclude the synapomorphy, more mitogenomes of Pyrrhocoroidea need to be explored. In this study, additional two mitogenomes of Pyrrhocoroidea(Macrocheraia grandis grandis(Gray, 1832) and Myrmoplasta mira Gerst-cker, 1892) were sequenced. Both of them also possess the same translocation between tRNA-Thr and tRNA-Pro, which reaffirms that this kind of rearrangement is a molecular synapomorphy of Pyrrhocoroidea. Moreover, we discovered a more complex rearrangement in Myrmoplasta mira, in which six nearly identical duplications of tRNA-Thr were found located downstream of tRNA-Pro. Considering the high biodiversity of Heteroptera, more mitogenomic studies are needed to improve our knowledge about mitogenome rearrangements and the potential synapomorphies.
基金Supported by National S&T Support Program (2006BAD09A02)NSFC (39700017)
文摘Scallops of the Family Pectinidae are a valuable resource in marine industry of the world. Understanding the phylogeny of the family is important for the development of the industry. In this study, partial 16S mitochondrial rDNA genes were obtained from 8 scallop species that are commonly cultured indigenous and transplanted species in China. Phylogenetic relationships of Pectinidae were analyzed based on the 8 sequences and other 5 published ones in GenBank, representing 9 genera of the family. The molecular phylogeny trees were constructed using 3 methods with software PHYLIP. The results showe that total 13 species of scallops clustered in 4 clades. Pecten maximus joins P. jacobaeus then Amusium pleuronectes in cluster, indicating close relationship of genus Amusium with Pecten in evolution. P. yes- soensis is close to Chlamys farreri and C. islandica. No enough material was available to single out genus Patinopecten as an independent monophyletic subfamily. The position of Adamussium colbecki indicates that it is far from genus Pecten but near to genus Chlamys in evolution.
