Here we use amplified fragment length polymorphism （AFLP） to assess genetic differentiation of Helicoverpa armigera and H. assulta. The results indicated that both species-specific fingerprints and cluster analysis ...Here we use amplified fragment length polymorphism （AFLP） to assess genetic differentiation of Helicoverpa armigera and H. assulta. The results indicated that both species-specific fingerprints and cluster analysis showed the ability of AFLP technique to discriminate the two sibling species; among a total 1963 AFLP markers amplified from nine primer combinations： 777 （39.6%） were H. armigera-specific, 602 （30.7%） were H. assulta- specific, and 584 （29.7%） were common bands. The mean number ofH. armigera-specific bands was significantly more than that of H. assulta-specific bands for nine primer combinations （P 〈 0.05）; the intraspecific distance of H. armigera and H. assulta was 0.123 0 and 0.110 7 respectively, and the interspecific distance was 0.178 3. In addition, the percentage of polymorphic loci and estimated average heterozygosity were used to estimate genetic diversity of the two species. This study therefore demonstrates that AFLP analysis is a sensitive and reliable technique to study genetic differentiation and genetic relationships between species and provides sufficient molecular markers for future linkage map conslruction, location and eventual cloning of genes involved in traits differentiation.展开更多
Common DNA-based species determination methods fail to distinguish some blow flies in the forensically and medically important genus Lucilia Robineau-Desvoidy.This is a practical problem,and it has also been interpret...Common DNA-based species determination methods fail to distinguish some blow flies in the forensically and medically important genus Lucilia Robineau-Desvoidy.This is a practical problem,and it has also been interpreted as casting doubt on the validity of some morphologically defined species.An example is Lucilia illustris and L.caesar,which co-occur in Europe whilst only L.illustris has been collected in North America.Reports that these species shared both mitochondrial and nuclear gene sequences,along with claims that diagnostic morphological characters are difficult to interpret,were used to question their separate species status.We report here that amplified fragment length polymorphism profiles strongly support the validity of both species based on both assignment and phylogenetic analysis,and that traditional identification criteria based on male and female genital morphology are more reliable than has been claimed.展开更多
Species of the genus Myceliophthora and its teleomorph Corynascus have attracted increasing interest due to their potential to produce thermostable enzymes.This study re-assessed the phylogenetic relationship of 49 is...Species of the genus Myceliophthora and its teleomorph Corynascus have attracted increasing interest due to their potential to produce thermostable enzymes.This study re-assessed the phylogenetic relationship of 49 isolates of nine species belonging to Myceliophthora and Corynascus.One species,M.vellerea,was shown not to belong to the genus Myceliophthora and should be placed in the genus Ctenomyces.The other species belonged to two phylogenetic clusters:mesophilic fungi with the type species M.lutea and C.sepedonium,and thermophilic fungi with M.thermophila,M.hinnulea and C.thermophilus.The phylogenetic data provides no clear separation of the two genera Corynascus and Myceliophthora.To avoid confusion in future taxonomic studies,it is proposed that all existing Corynascus species be renamed to Myceliophthora,which is the old name and the one more frequently used.Furthermore,this study identified two groups within the isolates listed as M.thermophila and assigned one group(five isolates)to M.heterothallica based on AFLP analysis and mating behavior.This study provides new insights into the genetic differences within the genus Myceliophthora and will therefore be essential for the interpretation of future genomic and physiological studies of these species.展开更多
基金We thank Si-Ping Li for technical contributions to this study, Dr Shi-Liang Zhou （Institute of Botany, Chinese Academy of Sciences）, Jian-Cheng Shen and Qing-Bo Tang for data processing, and Li Feng for help in rearing insects. We are particularly grateful to Dr De-Xing Zhang for his constructive comments that greatly improved the manuscript. Also we appreciate thoughtful discussions with Professor Li-Huang Zhu （Institute of Genetics and Developmental Biology, Chinese Academy of Sciences）. This work was supported by the National Natural Science Foundation of China （Grant Nos. 30330100 and 30471148）.
文摘Here we use amplified fragment length polymorphism （AFLP） to assess genetic differentiation of Helicoverpa armigera and H. assulta. The results indicated that both species-specific fingerprints and cluster analysis showed the ability of AFLP technique to discriminate the two sibling species; among a total 1963 AFLP markers amplified from nine primer combinations： 777 （39.6%） were H. armigera-specific, 602 （30.7%） were H. assulta- specific, and 584 （29.7%） were common bands. The mean number ofH. armigera-specific bands was significantly more than that of H. assulta-specific bands for nine primer combinations （P 〈 0.05）; the intraspecific distance of H. armigera and H. assulta was 0.123 0 and 0.110 7 respectively, and the interspecific distance was 0.178 3. In addition, the percentage of polymorphic loci and estimated average heterozygosity were used to estimate genetic diversity of the two species. This study therefore demonstrates that AFLP analysis is a sensitive and reliable technique to study genetic differentiation and genetic relationships between species and provides sufficient molecular markers for future linkage map conslruction, location and eventual cloning of genes involved in traits differentiation.
文摘Common DNA-based species determination methods fail to distinguish some blow flies in the forensically and medically important genus Lucilia Robineau-Desvoidy.This is a practical problem,and it has also been interpreted as casting doubt on the validity of some morphologically defined species.An example is Lucilia illustris and L.caesar,which co-occur in Europe whilst only L.illustris has been collected in North America.Reports that these species shared both mitochondrial and nuclear gene sequences,along with claims that diagnostic morphological characters are difficult to interpret,were used to question their separate species status.We report here that amplified fragment length polymorphism profiles strongly support the validity of both species based on both assignment and phylogenetic analysis,and that traditional identification criteria based on male and female genital morphology are more reliable than has been claimed.
基金supported by the EC 7th Framework program(NEMO,Project Grant agreement 222699).
文摘Species of the genus Myceliophthora and its teleomorph Corynascus have attracted increasing interest due to their potential to produce thermostable enzymes.This study re-assessed the phylogenetic relationship of 49 isolates of nine species belonging to Myceliophthora and Corynascus.One species,M.vellerea,was shown not to belong to the genus Myceliophthora and should be placed in the genus Ctenomyces.The other species belonged to two phylogenetic clusters:mesophilic fungi with the type species M.lutea and C.sepedonium,and thermophilic fungi with M.thermophila,M.hinnulea and C.thermophilus.The phylogenetic data provides no clear separation of the two genera Corynascus and Myceliophthora.To avoid confusion in future taxonomic studies,it is proposed that all existing Corynascus species be renamed to Myceliophthora,which is the old name and the one more frequently used.Furthermore,this study identified two groups within the isolates listed as M.thermophila and assigned one group(five isolates)to M.heterothallica based on AFLP analysis and mating behavior.This study provides new insights into the genetic differences within the genus Myceliophthora and will therefore be essential for the interpretation of future genomic and physiological studies of these species.
