ABSTRACT
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 simple sequence repeat (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 was non-random spatial structure. When the distance band increased, the spatial auto-correlativity decreased based on the average Moran' s I value at 14 distance band. The alleles which showed a negative spatial autocorrelation were not found in any distance band. Conclusion The spatial distribution of the genetic variation of SSR showed positive spatial autocorrelation in the population of Oncomelania hupensis, and the spatial auto-correlativity decreased with the increase of distance band.
ABSTRACT
Objective To analyze the sequence of microsatellite and the flanking sequence from four populations of Oncomelania hupensis. Methods We cloned 159 SSR-PCR amplification products of a commonly used primer, (CA)8RY, using O. hupensis genomie DNA as template, and sequenced 82 products Results The sequences obtained were novel O. hupensis genomic sequences but not repeat simple sequence. It was observed that 36 out of 82 clones contained microsatellites between priming sites.The flanking sequences of certain microsatellite were invariant. Both (GA/CT). and (TTAGGG/CCCAA)n were found in four populations of O. hupensis. However, (CAA)n were found only in O. hupensis from Fuqing,Fujian province and (TCTCTG), were found only in O. hupensis from Guichi,Anhui province and (GAA/TTC)n, (CAA/TTG)n, (CAT), were found only in O.hupensis from Puge,Sichuan province. Conclusion The results obtained 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 could not make the most of the priority of microsatellite. It seems better to amplify the microsatellites with the primers designed on the basis of the flanking sequence.