Study Of Population Genetic Structure Of House Mouse Mus Musculus Castaneus In Shanghai

Genetic polymorphism molecular markers were used in this study to explore genetic diversity of house mouse in Shanghai city and their relations with geographic distribution. Five autosomal STR and seven newly-developed SNPs in the coding region of mitochondrial DNA were genotyped in 112 house mice in Shanghai. The samples were collected from five different areas in Shanghai: Chong-ming region (CM), Qing-pu region (QP), Jin-shan region (JS), Jia-ding region (JD) and Song-jiang region (SJ).To discovery new mutation patterns in house mouse, universal primer florescent PCR, fluorescence-based conformation sensitive gel electrophoresis (F-CSGE ) and DNA sequencing were conducted in this study to analyze the coding region of house mice mitochondrial DNA. Ligase detection reaction technology was applied to genotype the gene polymorphisms discovered by F-CSGE. STR genotype in house mice was accomplished by fluorescence PCR technology.In this study, 23 mutations were detected within 5kb of the coding region of mitochondrial DNA, 15 of which were were found new to the current SNP databases. Seven tag-SNPs L350, L366, L543, L572, L716, L953 and L964 were applied to analyze the genetic diversity of different house mouse populations. The distributions of the seven mtSNPs in Shanghai shown by allele frequencies were: L350 (T82%, C18%), L366 (C88%, T12%), L543 (A92%, G8%), L572 (T79%, C21%), L716 (T77%, A23%), L953 (T89%, C11%), L964 (G78%, A22%). The distribution patterns of mtSNPs L572 C>T, L716 A>T and L964 A>G were of discrepancy among different populations.Nine mitochondrial haplotypes were constructed among house mice population in Shanghai. Haplotype 5 (H5: TCATTTG) was regarded as ancestral haplotype in Shanghai because it presents in all populations with an overall higher frequency. The haplotype H5 was consistent with the haplotype sequence of Japan-derived house mouse subspecies (Mus musculus molossinus), but different from laboratory inbred mice (TTATWTG (W: A/T)) and Europe-derived house mouse subspecies (Mus musculus domesticus: TCATATG). This result provide new evidences to support the migration hypothesis that Mus musculus castaneus shares common ancestor with Mus musculus molossinus, but different from Mus musculus domesticus.AMOVA results showed most genetic variations exist within mice populations according to autosomal STR. But for mtSNPs, there is a large proportion of genetic variation between Chongming (CM) population and the other four populations, for the population in Chongming Island are isolated by the Yangtze River. The Phylogenetic tree based on autosomal STR was different from the one on mtSNPs. This discrepancy may be due to the molecular stability and genetic characteristic between autosomal STR and mtSNPs. Compared with mtSNPs, autosomal STR is not stable and influenced by both paternal and maternal genetic background.In conclusion, the data illustrate that genetic diversity of house mouse is remarkable in Shanghai and genetic relationship between populations is consistent with the geographical distribution of the five mice populations. Chon-gming house mouse population was regarded as a relative separated population. The affluent genetic diversity in house mouse (living in wild environment) can offset the drawbacks of genetic deficiency in laboratory inbred mice and make it possible to perform high-resolution mapping of Quantitative Trait Loci (QTL). This study indicated that house mice could provide a useful tool for identifying genes that cause variation in complex traits.