Study On Polymorphisms Of Red Steppe Cattle By Microsatellite DNA

Red Steppe Cattle is a new cattle breed cultivated from Mongolian Cattle.It have a lot of welcome characters such as performance traits,and being adapt to the climate of the northeast areas of china. Genetic variation should to be taken into account to guide genetic conseveration programs. While highy polymorphic microsatellite DNA marker provide a good tool to assess the genetic variation. So using microsatellite marker to analyse the genetic variation is critical necessary for the Red Steppe Cattle breeding. Blood or tissue samples were colledted randomly from five cattle breed(stranins) consisting of (Charladies Cattle (CH), Limousin Cattle (LM), Simmental Cattle (SM), Red Steppe Cattle(RSC), Mongolian Cattle(MG). The number of DNA samples were 66 for all cattle population,respectively. Genomic DNA was extracted by a standard phenol-chloroform protocol with some modification. Eight microsatellite loci was chosen from Genbank(IDVGA2,IDVGA46,TGLA44) or isolated from a genomic library(BM1824,ETH225,BM2113,IDVGA44,IDVGA55). 8 microsatellite loci (IDVGA2,IDVGA46,TGLA44,BM1824,ETH225,BM2113,IDVGA44,IDVGA55) was used to analyse the population genetic variation among 5 breeds or strains of domestic cattle population (Charladies(CH), Limousin(LM), Simmental(SM), Red Steppe Cattle(RSC), Mongolian Cattle(MG)). 8 microsatellite loci exhibited a total 40 alleles from the 5 cattle population. One private allele was found at Red Steppe Cattle population by IDVGA46,Another private allele was found at MG population by BM1824. Polymorphism Information Content(HIC) and heterozygosity(H) had the same tendencies among 5 cattle population, and the RSC population had the highest value (0.65823,0.6953), followed by MG population (0.61645,0.6670), CH population (0.56708,0.6382), LM population(0.52825,0.6020), and SM population 0.52816,0.5858), which suggested that genetic variation was greater in Red Steppe Cattle population than in the other four cattle populations. The result of cluster displayed that the population whose relationship was nearest to Red Steppe Cattle population was Mongolian Cattle population, followed by Charladies population, Limousin population and Simmental population, Mongolian Cattle population was the furthest one to Red Steppe Cattle population in relationship, which conformed to the fact of the Red Steppe Cattle breeding history. Comparative measures of genetic variaion for each cattle population were caculated in the form of allelic diversity(total number of allele ,mean number of allele per locus, frequency of every allele in each cattle population), observed polymorphismsoftware of PPAP (Z.Guo, X.Li, 1994). Genetic distance (D) was caculated aslo by PPAP softwere, and the Phylogenetic tree were construted using UPGMA.Genetic variation within population. In the experiments microsatellite DNA method were compared with biochemical markers analysis in analyzing five groups of eight domesticstrains(IDVGA-2,IDVGA-46,TGLA-44,BM1824,ETH225,BM2113,IDVGA-44,IDVGA-55) Which amplified 6,6,6,5,4,2,6,4 alleles and average alleles 4,4,4,4.2,3.6,3.4,2,4.8,3.2. Amply fragment is from 100bp to 300bp.One is that characteristic fragment of RSC(Red Steppe Cattle) was obtained by TGLA-44 from the microsatellite map,the polymorphism information content (PIC) and Heterozygosity (H) were calculated by PPAP software. The result shows that both the PIC and the in RSC population are the highest(0.65823 and 0.6953), while both in SM( Simmental ) population are the lowest(0.52816 and 0.5858),which suggested that the geneticvariation than the other population,the PIC and H of IDVGA-2 are the highest(0.6861 and 0.7337) in eight primers. It is proved that Microsatellite DNA are more accurate,reliable and more precise in variation level and heredity distance of animal individual. The result of cluster displays the population whose relationship was the nearest to RSC population is MG(Mongolian Cattle) population (0.2786), followed by CH(Charladies) population(0.3059),LM(Limousine) population(0.3892) and SM(Simmental) population (0.4184), which conformed to the fact of the RSC breeding history. In additional, microsatellite map of the breeds strains was also obtained by multiple microsatellite PCR and DNA pool. The result shows that the method of multiple microsatellite PCR and pool are simple, fast, cheap and saving time than standard microsatellite PCR. 3 microsatellite markers were discovered to have positive or negative correlation with some growth and meaty traits in the population of Red Steppe Cattle and its improved hybrid by Limousine ( LM ) .For microsatellite loci IDVGA46,allele D(211bp) had a negative correlation with Body height,Height at hip cross(HHC) and Height at capitulum body measurement traits, allele B(205bp) had a positive correlation with waist corner width. For allele D(249bp) had a positive correlation with the Grouth traits.For BM1824,allele C(211bp) had a positive correlation with Height at hip cross(HHC) and Loin thickness.For IDVGA2,allele (205bp) had a negative correlation with withers,loin thickness ,buttocks shape,body weight,carcass weight and net meat weight. This research showed high variation within and between the cattle populatios in this study and also proved that microstellite genotyping is an useful tool to evaluate the variation and evolutionary relationships among...