FSHβ基因和FSHR基因态性及其对小尾寒羊产羔数的遗传效应-动物遗传育种与繁殖专业毕业论文.docx

甘肃农业大学硕士学位论文 甘肃农业大学硕士学位论文 2008届 Summary In this paper single nucleotide polymorphisms of follicle—stimulating hormone beta-subunit (FSHfl)gene at CDS regions(exon2 and exon3)and FSHR gene at exon l O were detected by PCR—SSCP in Small Tailed Han Sheep，Tibetan Sheep，Gansu Alpine Merino，Texel sheep and crossbred of Poll Dorset and Mongolian，genetic polymorphisms of FSHfl gene at CDS regions and FSHR gene at exonl 0 in different sheep populations were explored and its genetic effect on litter size were analyzed in Small Tailed Han Sheep．These results will provide effective molecular marker for selectively breeding about hiI曲prolificacy in sheep．The results are as follows：① Genetic polymorphisms of FSHfl gene at exon2 in 5 sheep populations had been detected．But FSHfl gene at exord and FSHR gene at exon 1 0 had no polymorphism．@There was one single nucleotide mutation(T147_C147)at exon 2 of FSHfl in the BB genotype in comparison to the AA genotype，but this mutation did not cause amino acid change．(重)Genotype distribution had some differences between five populations。The results of Hardy—Weinberg equilibrium test indicated that the studied populations except Texel reached equilibrium p0．05)．All of the populations had intermediate polymorphism information contents(0。25PIC0．5)．@The results showed that the FSHfl gene is either a major gene that influences the prolificacy in Small Tailed Han Sheep or a molecular marker in close linkage with such a gene，AA genotype could increased litter size in sheep．Therefore，improving litter size of sheep Was reasonable using marker assisted selection of OBased on CDS regions sequences of FSHfl gene in ten species(sheep，goat，bovine， 甜口，．)，Neighbour—Joining tree and Minimum—Evolution tree were reconstructed．The results showed that two trees had same topology structure and high bootstrap value(70)，comparing results of construction、Ⅳitll evolution results in animal kingdom revealed that related species in taxonomy were respectively grouped t