DNA Molecular Markers On Bovine And Ovine Fecundity Traits

60 cows from two bovine breeds (Qinchuan cattle and Holstein cattle) and 197 sheep from six ovine breeds (Small Tail Han sheep with prolific traits , Big Tail Han sheep with twinning trait, and Mongolia sheep and Kazakh sheep and Lanzhou Big Tail sheep with 1 lamb per lambing ) were analysed by RAPD, PCR-RFLP, microsatellite, PCR-SSCP and squencing markers , The object was to obtain effective markers for t ovine and ovine fecundity traits , as well as provide some scientific basis for searching for twining gene in bovine and prolific gene in ovine and for selecting and breeding prolific bovine and ovine . The study results were as follows:1 The marker results for bovine twining traits:1.1 Micosatellite markers 12 microsatellites from Bos tauras autosome were amplified effectively in DNA pools of monovular cows , twinning cows and special twinning cows (often bear twin calves), of which 4 microsatellite loci could marker bovine twining traits. As follows:Special twining cows have no 230bp allele compared with monovular cows at HEL13 locus.Special twining cows have no 263bp allele compared with monovular cows at BM1824 locus.(3) Special twining cows have 222bp and 206bp alleles, but monovular cows have not that at ETH152 locus.Special twining cows have no 217bp allele compared with monovular cows at INRA005. These results appeared in two cattle breeds 1.1.2 PCR-RFLP markers PCR-RFLP in FSHR gene 5'-flanking region which includes exon 1 digested with restriction endonuclease Taq I demonstrated that the frequency of allele A (0.5500) and genotype AA (0.5000) in twinning cows were higher than that of allele A (0.3500) and genotype AA (0.300) in monovular cows for Qinchuan cattle, while The frequency of allele B (0.5937) and genotype BB(0.6875) in twinning cows were higher than that of allele B (0.5416) and genotype BB (0.4167) in monovular cows for Holstein cattle.1.3 PCR-SSCPmarkers Results of bovine FSHR gene exon 10 analysed with PCR-SSCPshowed that the mutation frequency with 60% in twinning cows was higher than in monovular cows (20%) in Qinchuan cattle; and the mutation frequency was 31.25% in twinning cows and 6.67% in monovular cows for Holstein cattle respectively. The results provided a reliable evidence for bovine prolific reproductive traits.1.4 Sequencing Sequencing for FSHR gene exon 10 demostrated that there was a mutation locus at 1506bp, i.e. T-C, but amino acid which coded had no change. These results appeared in two cattle breeds.2 Molecular markers for ovine fecundity traits:2.1 RAPD markers 5 RAPD primers selected from 30 primers were used to estimate the correlation between the markers and litter size of Small Tail Han sheep. The results showed that the sixth band of primer 0424-198 had a significant positive correlation with litter size (P<0.05), and the seventh band of this primer had a significant negative correlation with litter size (<0.01); The seventh and eighth bands of primer CY0184 almost reached significant positive correlation with litter size.2.2 Microsattelites markers Four microsatellite loci mapped at chromosome 6 and lingked to FecB gene (OarHH35, OarAElOl, BM1329, BM143, OarHH55) and another microsatellite locus mapped at chromosome 4 (OarHH55) were selected to detect the correlation with litter size traits in six sheep breeds. The results were followes:(1) The PIC of 5 microsatelite loci all reached high polymorphism (PIO0.7), it identified Chinese sheep have abundant genetic diversity.(2) 5 mcrosatellite loci makers for the litter size of Small Tail Han sheep indicated that the OarAElOl was best one , BM1329 was better than BM143 and OarHH35, there were no any effective markers at OarHH55.(3) 15 effective markers from above five microsatellites were discovered to marker the litter size of Small Han Sheep. Realts as follows:5 markers from five microsatellites had been detected the significant positive correlation with the litter size (.PO.01), i.e. OarAElOl-E (113bp, r = 0.5295) > BM1...