Study On Correlative Genes Of Litter Size Traits And Genetic Diversity Of Mink

Mink is widely breeded in the part area of China as a main economic animal. Litter size is one ofthe most important economic traits in mink industry, and more litter size can increase minkproduction and bring about more economic benefit for mink industry. Therefore one of major goalin mink breeding is to increase the litter size. It has important significance for mink's breedselection that molecular genetic mechanism of it's litter size traits is studied by modern molecularbiological technology.In this paper, ESR, FHSβ, FSHR, PRLR were selected as the candidate genes of litter size traitsand number born alive traits. PCR-SSCP analysis was applied to detecting the SNPs of fourcandidate genes, and analyzed the relationship of polymorphism of the mutational site and littersize traits, number born alive traits in mink.With the development of mink cultivation, some chromatic colour mink appeared one afteranother. But there are few reports about the genetic relationship of mink and chromatic colour mink.For the sake of revealing varietal genetic relationship of mink, three varieties which werestandard-pitchy mink, sapphire mink, pastel mink were selected in this research, and applied RAMPmarkers to analyzing their genetic relationship. Main research results as follows:(1) The exon 1 and 7 of ESR gene were detected. A SSCP marker was founded in the exon 1.The mutation G256C resulted in a change of amino acid (glycine→alanine), the mutation ismissense mutation. There were two genotypes in the exon 7 of ESR.(2) In the polymorphism locus of the exon 1, in mink population, the AA genotype waspropitious to the litter size. In the exon 7, the two genotypes didn't have an effect on litter size andnumber born alive.(3) There was a mutation site in the exon 3 of FSHβ, the mutation C75T resulted in a change ofamino acid (proline→leucine), and in the mutation site three genotypes were detected, which hadan effect on litter size traits of mink (P=0.0516).(4) The exon 10 of FSHR was detected, there was a polymorphic site in the 741 (A→C), themutation was silent mutation. The polymorphisms of the exon 10 had a distinguished tendency tonumber born alive of mink.(5) In mink population, the SSCP was not detected in the exon 2 and the exon 10 of PRLRgene. (6) In RAMP molecular markers analysis, 14 couple primers from 240 random ones were usedto amplify 89 mink samples. 14 primer combinations amplified 81 bands, 75 bands werepolymorphic. The polymorphic percentage was 92.59%, 4～8 bands were amplified by each primercombinations, with an average of 5.78 bands. The genetic similarity coefficient ranged from 0.3469to 0.9796, with the mean of 0.610. The cluster analysis indicated that all the 89 mink samples couldbe distinguished by RAMP markers. Polymorphic bands percentage, Shannon's Information index,Nei's(1973) gene diversity showed high genetic diversity. Nei's genetic distance, Shannon'sInformation index and the coefficient of gene differentiation were used to analyze populationgenetic differentiation and the results showed that the genetic differentiation degree betweenpopulations was lower and the hereditary variation primarily came from within population.