DNA Molecular Markers On Some Economic Traits In Xinong Saanen Dairy Goat

Xinong Saanen dairy goat was breeded by Northwest University using Saanen dairy goat introduced from America and England during the 1920s~1930s. This breed was such characteristic as tall body, good adaptation, stable inheritance and high milk production. In the experiment, the milk production traits were analyzed by RAPD, PCR-RFLP, PCR-SSCP and microsatellite, while birth weight, size and development were analyzed by RAPD. The aim was to discover the hereditary characteristic and to find DNA molecular markers which have effects on milk production and some economic traits as talked above. We hope that both the work and its result can provide data for Xinong Saanen dairy goat and it's breeding. The main results were as follows:1. The hereditary characteristic of RAPD. 6 primers, selected from 64 random primers, amplified 56 bands; among which 34 bands were polymorphic and its variational rate were 58.6%. From the PCR production of 6 primers, their average bands sharing rate was calculated as 0.8808 ?.086, and polymorphic index was between 2.2120-2.2674.2. Four type of DNA markers and it's relationship with some economic traits.2.1 RAPD markers: 6 marked bands were found having significant effects on milk production, especially the marker band L6-I (890bp) had a very significant effect (P < 0.05) on the first, second lactation and total milk production. Obvious combining forms were not found between gene band and milk yield. The band OPW19CS had significant effect on birth weight and bodyweight, the goat without the band developed better than the individuals with it, particularly, it's effect on birth weight is very significant (P < 0.01). Same as this, without the band OPQ05-B, the goat got a bigger heart-girth and body weight than the comparing group.2.2 PCR-RFLP marker: 56 milk goats were analyzed in the experiment. P-lg gene's 51 flank region(71 Obp) including 588bp of the upstream and 122bp of the exon I, whichwas amplified with PCR-RFLP, two alleles, A ana B were round m the locus. The two genes were in the state of Hardy-Weinberg's balance with the gene frequency of A:0.91, B:0.09. Goat of AA type showed better milk production in 2nd , 3rd and total lactation than AB type(P < 0.05), no BB type were fount in the experiment.2.3 PCR-SSCP marker: Two new alleles of exon 4 of K -casein were discovered by PCR-SSCP in 56 Xinong Saanen dairy goat. With the A gene frequency of 0.6875 and B: 0.3125 the new alleles were not in the state of Hardy-Weinberg balance. Further analysis and calculation told us: goat with AA type, its milk performance were better than those with AB or BB type. The difference was significant in 1st, 4th and total milk yield (P < 0.05). No clear difference between AB and BB type were detected.2.4 Microsatellite marker: In this experiment 13 and 6 pairs primers of cattle and sheep were used in the PCR reaction of Xinong Saanen goat gnome DNA. The electrophporesis patterns of amplified products were clear, but no polymorphism was attained in the 19 primers.