| Chinese yellow cattles distribute throughout the country and is one of the most important composition of world cattle owing to their large number and abundant breed type. But in the recent years, influencing by living environment, human's activity and invasion of foreign breeds, the genetic diversities deduced quickly. It is very necessary to assess the characteristic of genetic resources of animal and poultry, make reasonable protecting and using measures, which is favorable to cattle industry, especially to the cultivation of new varieties and breeds. However, mitochondrial DNA is a useful tool to study genetic and differentiation not only intra- but also inter-species due to its especial characteristic such as rapid evolution, small genome, simple and steady conformation, lack of recombination, no speciality in tissues and single sex maternal heredity. Four local cattle breeds Luxi cattle( LX), Qinchuan cattle(QC), Nanyang cattle( NY) and Jinnan cattle( JN) are studied in this research. Peculiar primers are used to amplyfy special gene fragments. The results of the reseach are as follows:Left domain in the D-loop are analyzed with SSCP. Result showed that five band types are found in each breed and four of them are shared such as A, B, C, D, which showed that abundant polymorphysms appeared intra-species. Ten individuals whose band type are not complete same are sequenced. The other twelve sequences(including Menggu cattle(MG)) from Genebank are cited to analyze haplotype of the sequences and genetic diversities. A base pair differentiation appears between the sequences whose band type is A, B, D and the similars, so they are defined haplotype â… , â…¡and â…¢. But differentiations between band type C and its similar are greater, we define them as haplotype â…£ and â…¤ in view to discrepancy of two base pair. Genetic distance between Haplotype â…¡ and others are the greatest. Phylogenetic development showed that haplotype â…¡ is origin from bos indicus and bootstrap value is 100%. However, other haplotypes are origin from bos taurus. NY, JN and LX predominate in haplotype â…¡. The proportion of haplotype â…¡ in NY reach 66%, but QC only 16%. We can conclude that the influence from bos indicus of NY is fairly great, but the ones of QC is very little.The result of genetic diversity showed that the left domain is rich of A/T base pair and transition bias. 38 polymorphism sites except for insert/delete sites are found in this domain. In these sites, 6 are single site and the other 32 are parsimony information sites. Nucleotide discrepancise (Dxy) of five breeds alternates between 0.01396-0.04490 and Kimura two-parameter distances change between 0.0133-0.047. All of this tell us abundant polymorphysms appeared inter-breeds.Dendrogram constructed from the genetic distance among LX, NY, QC, JN, MG, Europe cattle and Indian zebu showed that relationship among QC and MG is closer to Europe cattle but NY is closer to Indian zebu.Mutation rate of D-loop is 11%, six times to ND5 gene and twenty-three times to cyt b. So D-loop is a useful tool to analyze the phylogenetic development between inter-breeds of intra-species.Part of cyt b gene about 250bp is analyzed with SSCP but only two band types are examined. The result of sequence showed that one base pair differentiate them. The frequency of each type in four breeds is similar. So it is difficult for cyt b to analyze the dendrogram between breeds of species.Part of ND5 gene are analyzed with RFLP by four restriction enzyme Hindâ…¢,Speâ… ,Haeâ…¢and EcoRâ… . Two polymorphysm sites were detected in the amplified ND5 region, with the enzymes Hindâ…¢and Speâ… . Only two haplotype were seen: haplotype â…¡equivalent to the sequence published by Anderson, and and haplotype â… , with loss of Hindâ…¢and Speâ… sites. The loci were strongly linked, as expected for the nonrecombining mitochondrial genome. In the former research, haplotypeâ… is thought to origin from bos indicus and haplotype â…¡ from bos taurus. Each breed showing either haplotypeâ… or haplotype â…¡ for both loci and si...
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