摘要
In this report, genetic variation and phylogeny of B. acheilognathi were analyzed based on 96 samples collected from 20 fish host species in 29 different localities by using the rDNA internal transcribed spacer （ITS） sequences. The ITS1 and ITS2 sequences of B. acheilognathi varied among 561-639 bp and 559-648 bp, and ten simple sequence repeat loci （microsatellites） were detected in the ITS regions, which contributed to significant sequence length variation. Phylogenetic analyses revealed 4 genetic clades （A, B, C, D） in samples with significantly different fish host spectra and geographic distribution. Clade A possessed a wide host range and geographic distribution, including all the samples ofB. acheilognathi determined in previous report. Clades B, C, and D only infected the small cyprinid fishes Opsariichthys bidens and Zacco platypus, and were limited to different locality. Interesting, Clades A and D were detected coexisting in same water body, and even in same fish host O. bidens in Danjiangkou Reservoir. The relatively higher genetic divergence and wide geographic distribution orB. acheilognathi parasitic in O. bidens indicated that O. bidens is likely to be the primary host. Sympatric occurrence of the two genetically distinct clades suggests the possibility of allopatric speciation and second encounter events.
In this report, genetic variation and phylogeny of B. acheilognathi were analyzed based on 96 samples collected from 20 fish host species in 29 different localities by using the rDNA internal transcribed spacer （ITS） sequences. The ITS1 and ITS2 sequences of B. acheilognathi varied among 561-639 bp and 559-648 bp, and ten simple sequence repeat loci （microsatellites） were detected in the ITS regions, which contributed to significant sequence length variation. Phylogenetic analyses revealed 4 genetic clades （A, B, C, D） in samples with significantly different fish host spectra and geographic distribution. Clade A possessed a wide host range and geographic distribution, including all the samples ofB. acheilognathi determined in previous report. Clades B, C, and D only infected the small cyprinid fishes Opsariichthys bidens and Zacco platypus, and were limited to different locality. Interesting, Clades A and D were detected coexisting in same water body, and even in same fish host O. bidens in Danjiangkou Reservoir. The relatively higher genetic divergence and wide geographic distribution orB. acheilognathi parasitic in O. bidens indicated that O. bidens is likely to be the primary host. Sympatric occurrence of the two genetically distinct clades suggests the possibility of allopatric speciation and second encounter events.
基金
supported by the National Natural Sciences Foundation of China(31302222)
the Freshwater Fisheries Research Center,CAFS Grant(2013JBFM10)
the earmarked fund for China Agriculture Research System(CARS-46)
