| In this paper, the genomic DNA polymorphisms and the gene mutationrates of different sex sheep (goats) were mainly researched . The effect of the different sex animal during the evolution and protections of genetic diversity were further discussed. Phylogenetics trees of sheep(goats) were constructed on the sequences of these genes to probe into their relatives of phylogenesis.Firstly.two bulked DNA sampls were generated from female and male Tan-sheep with the help of BSA(Bulked Segregated Amplified).After establishment of the RAPD-PCR optimal conditions with the method of orthogonal design,two bulked sampls were screened for polymorphisms using one hundred and sixty arbitrary 10 meris-primers ,of which twenty five primers generated polymorphisms.The primers selected were used to screen sixty individuals of Tan-sheep(30 ,30 ).The results indicated that the method of orthogonal design could help establish the optimal and steady RAPD-PCR conditions quickly ,and the quality of genomic DNA was an important factor of requiring steady results of RAPD.Seen from the statistical comparision,the ABS and genetical distance of subgroups were 99.2%,0.008 respectively.The male subgroup(51%) had the higher polymorphisms loci than female one(48.4% ).The average value of the Hpop and positive frequency of polymorphisms loci female and male subgroup.There was remarkable difference in the Hpop and positive frequency of polymorphisms loci between two subgroup(P>0.05).This research showed:the male sheep had higher gene mutation rate than female ones.Meanwhile,it was found that SI44-1200 peculiarly existed in male sheep.and it was steady in male sheep of other breeds such as Xiaoweihanyang,Daweihanyang and Wadi sheep.then it could be used in the sex diagnosis of sheep.The last intron (~750bp)of Y-linked and X-linked zinc finger proteion genes (Zfy and Zfx) of Xiaoweihan-yang,Daweihan-yang,Lubei white goat and Boer goat (respectively 3 ,3 )were sequenced,and compared with the published sequences of44genebank.The ratio of substitution rate in the Y linked intron to that X linked was about 1.7 times. According to the format of Miyata(1987), We find that a m 2.66.and the 95% confidence interval for a m is roughly from 1.2 to 6.22. The result further indicated male sheep(goat) had higher mutation rate,and supported the view that the evolution of DNA sequence in sheep (goat) was mainly male-driven.From this study it was drawn the following conclusions:male sheep(goats)can provide more genetic variation to the group,and had higher contribution rate to the evolution of the sheep(goat) herds and perversion of group deversity than female ones.So in the theory and practice of protection of animal genetical resources,The traditional way of leaving more female and less male in the preserving stud herds.Comparing the a m of the homologue sites in rodents and higher primates,it was found a positive correlation between a m and animal generation time.And the results supporting the assumption that errors in DNA replication during germ cell division were the primary source of mutation.According to the fossil recorders and genetics distances between the last introns of Zfy and Zfx genes,their rates of the evolution can be assessed and the time when sheep-goat split happened be infered. The results revealed that the rate of nucleotide substitution was faster in Y-linked introns than that in the X-linked introns,and last introns of the Zfy and Zfx genes were 1.175><10~9/site/year,0.775xlO~9/site /year respectively.Then it can be indicated the time goat-sheep split was 23.4 Myr (Zfy) or 21.29 Myr (Zfx) .Goat-cattle split was prior to sheep-cattle ,and sheep had closer affinity relative to cattle than that of goat.The reseaches had solved the problem when sheep-goat split at the level of molecule, and provided one effective"molecular clock"for study of system evolution of ruminants.And trees constructed according to the last intron of Zfy indicated that it had good features for drawing phylogenetics tree at least among species...
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