| Genome DNA marking and analysis of 102 Nanjiang Yellow Goats was carried out by molecular marking techniques of radom amplificated DNA(RAPD), microsatellite and single nucleotide polymorphism(SNP) in this study. The purpose was to seek quantity trait loci(QTL) genetic markers of growth trait, to establish mathematic model for molecular marker data analysis, to analyze dependence relation between markers and growth trait. As the result, it will offer molucular genetics base for breeding on Nanjiang Yellow Goat and analysis methed for molecular marker data on other animal. The result of study as follow:1. Corelation analysis of RAPD markers and Traits of weight and body size(1) 4 Of 10 primers was slected for RAPD analysis on 102 samples of Nanjiang yellow goat. 33 visibile and bananced distribution segments were amplificated at all, 21 polymorphic segments of which. The polymorphic ratio was 58.86%, the segment length in the region of 180-2000bp. The result indicted that slected primers fited to analyze on Nanjiang Yellow Goat genome DNA.(2) The result of RAPD analysis showed that several markers close linked with researched traitsas follow: A05-B and A05-BF;F09-C and F09-CF;CY0817-A and CY0817-F;CY0818-A and CY0818-F, these markers all have signifficently effect on weight trait, in which, except A05-B, A05-BF and F09-CF also have have signifficently effect on body size traits, the others make non-signifficent effect.(3) Contribution ratio of substitution effect on weight of each marker is in the region of 6.72%-19.26%, among them, A05-B is the biggest for 19.26%, F09-CF next to it for 13.53%, CY0817-A and CY0818-A is lowest for 6.72%. Contribution ratio of substitution effect on body size of each marker is in the region of 1.14%-5.18%. It is negative correlation between body size traits and some markers, but is not significance difference.2. The correlation analysis of weight trait and microsatellite markers(1) Genetic parameter analysis of 10 microsatellite sites in population of Nanjiang Yellow goat indicated that, allele number is at 4-16, average allele number is 8.1, effective allele number is at 3.84-11.47, average effective allele number is 6.14;Polymorphic information content(PIC) is at 0.4611-0.7738, average is 0.5934;heterozygosity is at 0.7397—0.9128, average is 0.8203. Among the 10 microsatellite sites, INRA063 have minimum number alleles for 4, BM1227 have maximum for 16.(2) Mathematical model of correlation analysis of trait and microsatellite markers was established. In the situation of r_j is significant, this model can induced conclusion as follow: if r_j>0, it means positive correlation between the trait and marker. The bigger of r_j the more concordance between the trait and marker, the marker can be used in molecular marker assistant slect(MMAS);if r_j<0, it means negative correlation, incompatibility between the trait and marker. The smaller of r, the more concordance between the trait and marker, the marker also can be used in MMAS as a negative select.(3) The result of correlation analysis showed that these alleles make very significant positivecorrelated with body weight, such as BM3413-186,190, MFA70-109, INRA063-178,184, MB066-110, MB3501-176, correlation coefficient is at 0.5180-0.7375. BM3413-182, MFA70-115, MB066-98, these alleles make significant negative relation with bodyweight, correlation coefficient is at -0.6539~-0.3880.(4) Inbreeding coefficient genetic model was established, and inbreeding coefficient of Nanjiang Yellow Goat populatin was estimated by this model. The inbreeding coefficient of 10 microsatellite sites was at the region of 0.2065~0.5400, the average was 0.3677. This result was fitting to the reality of heigh close breeding with in-line breeding and blocked breeding in the population of Nanjiang Yellow Goat. In addition, to establish inbreeding coefficient with microsatellite markeers can overcome the difficult of classical genetic analysis for lacking pedigree information in the condition of pasturage or semi-pasturage in Nanjiang Yellow Goat population.3. SNP analysis of candidate genes which related to growth trait(1) The amplified products including 5'-region and exonl and part of intronl of GH gene was digested by Haelll, the results of PAGE and sequencing showed that there was a SNP site at +355, some samples lose the restriction site for base replacement (C—T) , there were 3 genotype were obtained in this site: AA(420/420),AB(420/354+66)and BB(354+66/354+66). The population was in Hardy-Weinberg balanced state in this site tested by x2.(2) The amplified product of GHR promoter PI at 5'-region was digested by Haelll, and 3 fragments(540bp/280bp/260bp) were obtained, the results of sequencing indicated that in the site of Haelll, some samples lose the restriction site for base replacement (C—T) .(3) The sequencing result of exon41 and part of coding sequence of IGF-1 showed that it was even conservative in this site, there are no mutation body in 20 samples.(4) The correlation analysis of weight and body size traits and SNP of GH gene: Typing of product of GH gene5'-region and exonl by PCR-RFLP, there were 3 genome types were obtained, AA, AB and BB. The body weight of samples with AA was significant less than population average, and AB was significant greater than the average, BB have no significant difference with population average. Body length of AA type was very significant greater than that of BB and average. The height at withers and heart girth of AB type was significant greater than the other 2 types and average. The result demonstrated that heterozygote is advantageous on body weight.(5) In the sequence of GHR promoter PI at5'-region, there are no significant difference between different genome types or each type and average by variance analysis.4. The research on consistent degree of different molecular marking method in Nanjiang Yellow Goat population(1) consistent degree calculation formula of different molecular marking method was established,kN C =------------^^---------x 100%, and consistent degree of 3 marking methods were calculated inNA+NB+- + Nknanjiang yellow goat, the consistent degree of RAPD and microsaatellite was 86.67%, RAPD and SNP was 77.19%, microsaatellite and SNP was 71.70%. The consistent degree was 63.53% if selecting by three kinds of markings at the same time.(2) It is not total consistence that to select by different marking in Nanjiang Yellow Goat population. In breeding practice, which molecular marking method should be used as MAS must in accordance with cases of condition, cost and convenience of the method, for more important, it must make sure according to breeding actual effect. 5. About sampling and marking methodThe result of study showed that, to search markers correlated with weight trait in the extram population that have great phenotype value variation, and then analyzing random samples with the markers to confirm their validity, this process can increase the efficiency of research and it is operable.
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