Three Closed Colony Of Rabbits Genetic Diversity

The genetic background of closed colony rabbits is complicated and the methodof quality monitoring has still not been established. Meanwhile, the traditional geneticmarkers, such as cytological and biochemical markers, can not be well applied inquality control because of their own limitations. With the development of molecularbiology, the advantage of molecular markers in the genetic quality monitoring oflaboratory animals is increasingly obvious, which can essentially showed DNAstructure differences and directly reflect genetic polymorphism in DNA level betweenindividual organisms. The digging of molecular markers and the establishment ofmolecular marker library provide a more favorable method for genetic monitoring oflaboratory rabbits.Two aspects about the D-loop region polymorphisms and microsatellite DNApolymorphism were comprehensive discussed in our research by using methods ofDNA sequencing, sequence alignment analysis and microsatellite genotyping toanalyze the genetic structure of three kinds of commonly used laboratory rabbits inChina. On the one hand, our results offered more information about D-loop sequencefeatures and the genetic diversity of three groups of closed colony rabbits in China.onthe other hand, it also provided more stable and reliable molecular markers for thegenetic quality control.In the study of DNA polymorphism of D-Loop region of the mitochondria, wedetected6polymorphic loci (Mostly Câ†'G mutation) in the71samples, five of whichoccurred at the same location of the5LR region;9haplotypes were defined, what’smore, the three populations shared respective haplotype, and did not overlap. D-loopregion is DNA control area of the mitochondria. There is a Long Repeat (LR)fragment in this region and most of rabbits in leporidae are5LR sequence. In ourresearch, All the Chinchilla rabbits are5LR sequence and10of28New Zealandrabbits are5LR sequence, the others being4LR.While20of21Japanese white rabbitsare5LR，only one being4LR. Overall, the polymorphisms of D-loop region of thethree groups are low, and the population genetic structures are stable.In the second part, we screened out18microsatellite loci, which were used toanalyze the genetic structure and population diversity. We counted allele frequency ofeach locus, the effective number of alleles, heterozygosity and F value, took theHardy Weinberg Equilibrium (HWE) test and polymorphic information content test,and Calculated the genetic distance (Nei’s1972and Nei’s1978) of the three populations. The results shows: among the group of Japanese white rabbits, theaverage number of alleles is observed at3.167, and the average effective number ofalleles is2.704; The average observed heterozygosity is0.4441, and the averageexpected heterozygosity is0.4678; The average polymorphism information content is0.41; The group significantly deviated from Hardy-Weinberg equilibrium (P(HWE)<0.05) on loci So144, INRCCDDV2016and INRCCDDV0344, but the polymorphicinformation content(0.3<PIC <0.8) are moderate highly polymorphic.AmongChinchilla rabbits：the average observation number of alleles is4.556, and the averageeffective number of alleles is2.704; the average observed heterozygosity is0.523, andthe average expected heterozygosity is0.5498; average polymorphism informationcontent is0.549; the group significantly deviate from Hardy-Weinberg equilibrium atloci6L2H3and Sat8, however, PIC on this two loci is in a high degree ofpolymorphism.Among New Zealand rabbits: the average observation number ofalleles is3.444, and the average effective number of alleles is2.359; the averageobserved heterozygosity is0.4976, and the average expected heterozygosity is0.53;The average polymorphism information content is0.470; The group significantlydeviate from Hardy-Weinberg equilibrium at loci6L2H3and7L3F2,but PIC on thistwo loci is moderate highly polymorphic.The genetic relationship is shown by population genetic distance. In our study,Chinchilla rabbits has the nearest genetic distance with New Zealand rabbits, being0.1241, and farthest genetic relationship with the Japanese white rabbits, being0.3203.The distant between New Zealand rabbits and Japanese white rabbits is0.3104.Above all, the genetic structure of closed colony rabbits cultivated for years isbecoming relatively uniform and the genetic differentiation between the populationsare obvious. Japanese white rabbits genetic structure is relatively single, the averagepolymorphic information content of the18loci is moderate polymorphism; Chinchillarabbit has the most abundant genetic diversity, polymorphism information content ishighly polymorphism; genetic diversity of New Zealand rabbits is relatively abundant,the average polymorphism information content is moderate polymorphism. Althoughthe three groups deviate from Hardy-Weinberg equilibrium on several loci, thepolymorphism information content is still relatively abundant within the scope of theclosed colony animals.