Simple Sequence Repeat Variation And Small-scale Spatial Autocorrelation Analysis Of Ocomelania Hupensis

Partâ… Sequencing of Simple Sequence Repeat Anchored Polymerase Chain Reaction Amplification Products of Oncomelania hupensis【Objective】The study aims to analysis the sequence of microsatellite in four populations of Oncomelania hupensis from Anhui,Sichuan,Fujian,Guangxi.And to analysis the flanking sequence in order to design primer for microsatellite amplification.【Methods】We cloned 159 SSR_PCR amplification products of a commonly used primer,(CA)₈RY,using Oncomelania hupensis genomic DNA as template,and sequenced 82 products.The sequences obtained were analyses by RepeatMasker.【Results】The sequences obtained were novel O.hupensis genomic sequences,not simple sequence repeat.It was observed that 36 clones out of 82 contained microsatellites between priming sites.The flanking sequences of certain microsatellite were invariant.Both(GA/CT)_n and(TTAGGG/CCCTAA)_n were found in four populations of O.hupensis.(CAA)_n were found only in O.hupensis from Fuqing, Fujian Province.(TCTCTG)_n were found only in O.hupensis from Guichi,Anhui Province.(GAA/TTC)_n,(CAA/TTG)_n and(CAT)_n were found only in O.hupensis from Puge,Sichuan Province.【Conclusions】The results ob- tained by SSR-PCR should not be interpreted as the amplification of microsatellite loci,and analytical rules similar to those for Random Amplified Polymorphic DNA should be used.SSR-PCR cannot make the most of the priority of microsatellite.It will be better to amplify the microsatellites with the primers designed on the basis of the flanking sequence. Partâ…¡Simple sequence repeat variation and Spatial autocorrelation analysis of populations of Ocomelania hupensis in Sichuan Province【Objective】To analysis the spatial autocorrelation on the small-scale distribution of the genetic variation in the population of Oncomelania hupensis in Puge county, Sichuan province,using SSR marker.【Methods】5 pairs of SSR primer were used to amplify the genomic DNA of Oncomelania hupensis,and the alleles with frequency ranging from 15%to 85%were used to calculate Moran's I spatial autocorrelation coefficients in 14 distance band based on equal numbers of paired samples.【Results】A total of 274 alleles were scored by 5 pairs of SSR primer,the average polymorphic information content of the 274 alleles were 0.965 which indicated a high level of genetic diversity.39 alleles showed different patterns of positive spatial autocorrelation of genetic variation,which is non-random spatial structure.While the distance band increased,the spatial auto-correlativity decreased based on the average Moran's I value at 14 distance band.The alleles show negative spatial autocorrelation were not found in any distance band.【Conclusions】The spatial distribution of the genetic variation of SSR was positive spatial autocorrelation in the population of Oncomelania hupensis,and the spatial auto-correlativity decreased with the distance band increased.