Population genetic structure of Carchesium polypinum (Ciliophora : Peritrichia) in four chinese lakes inferred from ISSR fingerprinting: High diversity but low differentiation
Chinese Acad Sci, Inst Hydrobiol, State Key Lab Freshwater & Biotechnol, Wuhan 430072, Peoples R China; China Univ Geosci, Sch Environm Studies, Wuhan 430074, Peoples R China; Chinese Acad Sci, Grad Sch, Beijing 100039, Peoples R China
WOS标题词:
Science & Technology
; Life Sciences & Biomedicine
类目[WOS]:
Microbiology
研究领域[WOS]:
Microbiology
摘要:
Although the peritrichous ciliate Carchesium polypinum is common in freshwater, its population genetic structure is largely unknown. We used inter-simple sequence repeat (ISSR) fingerprinting to analyze the genetic structure of 48 different isolates of the species from four lakes in Wuhan, central China. Using eight polymorphic primers, 81 discernible DNA fragments were detected, among which 76 (93.83%) were polymorphic, indicating high genetic diversity at the isolate level. Further, Nei's gene diversity (h) and Shannon's Information index (I) between the different isolates both revealed a remarkable genetic diversity, higher than previously indicated by their morphology. At the same time, substantial gene flow was found. So the main factors responsible for the high level of diversity within populations are probably due to conjugation (sexual reproduction) and wide distribution of swarmers. Analysis of molecular variance (AMOVA) showed that there was low genetic differentiation among the four populations probably due to common ancestry and flooding events. The cluster analysis and principal component analysis (PCA) suggested that genotypes isolated from the same lake displayed a higher genetic similarity than those from different lakes. Both analyses separated C. polypinum isolates into subgroups according to the geographical locations. However, there is only a weak positive correlation between the genetic distance and geographical distance, suggesting a minor effect of geographical distance on the distribution of genetic diversity between populations of C. polypinum at the local level. In conclusion, our studies clearly demonstrated that a single morphospecies may harbor high levels of genetic diversity, and that the degree of resolution offered by morphology as a marker for measuring distribution patterns of genetically distinct entities is too low.
英文摘要:
Although the peritrichous ciliate Carchesium polypinum is common in freshwater, its population genetic structure is largely unknown. We used inter-simple sequence repeat (ISSR) fingerprinting to analyze the genetic structure of 48 different isolates of the species from four lakes in Wuhan, central China. Using eight polymorphic primers, 81 discernible DNA fragments were detected, among which 76 (93.83%) were polymorphic, indicating high genetic diversity at the isolate level. Further, Nei's gene diversity (h) and Shannon's Information index (I) between the different isolates both revealed a remarkable genetic diversity, higher than previously indicated by their morphology. At the same time, substantial gene flow was found. So the main factors responsible for the high level of diversity within populations are probably due to conjugation (sexual reproduction) and wide distribution of swarmers. Analysis of molecular variance (AMOVA) showed that there was low genetic differentiation among the four populations probably due to common ancestry and flooding events. The cluster analysis and principal component analysis (PCA) suggested that genotypes isolated from the same lake displayed a higher genetic similarity than those from different lakes. Both analyses separated C. polypinum isolates into subgroups according to the geographical locations. However, there is only a weak positive correlation between the genetic distance and geographical distance, suggesting a minor effect of geographical distance on the distribution of genetic diversity between populations of C. polypinum at the local level. In conclusion, our studies clearly demonstrated that a single morphospecies may harbor high levels of genetic diversity, and that the degree of resolution offered by morphology as a marker for measuring distribution patterns of genetically distinct entities is too low.
Population genetic structure of Carchesium polypinum (Ciliophora Peritrichia) in four chinese lakes inferred from ISSR fingerprinting High diversity but low differentiation.pdf（307KB）
1.Chinese Acad Sci, Inst Hydrobiol, State Key Lab Freshwater & Biotechnol, Wuhan 430072, Peoples R China 2.China Univ Geosci, Sch Environm Studies, Wuhan 430074, Peoples R China 3.Chinese Acad Sci, Grad Sch, Beijing 100039, Peoples R China
Recommended Citation:
Zhang, Wen-Jing; Yang, Jun; Yu, Yu-He; Shu, Shao-Wu; Shen, Yun-Fen.Population genetic structure of Carchesium polypinum (Ciliophora : Peritrichia) in four chinese lakes inferred from ISSR fingerprinting: High diversity but low differentiation,JOURNAL OF EUKARYOTIC MICROBIOLOGY,2006,53(5):358-363
Population genetic structure of Carchesium polypinum (Ciliophora Peritrichia) in four chinese lakes inferred from ISSR fingerprinting High diversity but low differentiation.pdf
