| It could supply molecular data to assisted selection and early selection fine local breeds to studiy on genetic diversity of Jining Bai'ri chickens, the effect of DNA methylation difference on weight and laying traits, the effect of genovariation of FSHβgene and marker gene type on breeding characters, such as sexual precocity of chickens. The study worked on hereditary variation, DNA methylation level and so on, to announce the genetic diversity of fine local chickens, and genetic factor between growth and reproduction traits. The main results are as follow:Genetic diversity of Jining Bai'ri chicken was evaluated by microsatellites markers. The PCR amplified products of 60 individual microsatellites were detected. 10 pairs of primers out of 25 microsatellite loci were tested which were located on chicken 22 chromosomes, a total of 29 alleles were detected, and the number of alleles varied from 2 to 5, while the mean value is 2.90. The mean H and PIC of this population were estimated as 0.348 and 0.511. The results indicated that, four microsatellite loci had significant effect on some egg traits of Jining Bai'ri chicken (P<0.05 or P<0.01). Many favorable and disadvantages genotypes were be found. The most favorable genotypes for age at first egg (AFE) were AA at MCW0252, CC at MCW0029 and AA at MCW0097, while the disadvantages genotype were AB, AC, AD, CD and DD at MCW0252, CD at MCW0029 and AC at MCW0097.The most favorable genotypes for egg number at 43 weeks were AB at ADL0190, AD, BB and AC at MCW0029 and CC at MCW0029, while the disadvantages genotype were BB at ADL0190, DD at MCW0252 and AE, CD and DD at MCW0029.DNA methylation levels of thirty-six Wenchang chickens were detected by methylation-sensitive amplification polymorphism (MSAP), the individuals were divided into 6 groups according to global methylation levels, and the effect of DNA methylation level difference on weight and laying traits was studied. The result was showed that unmethylation levels, hemimethylation levels and fully methylation were 59.7%~75.3%, 9.4%~19.0% and 11.5%~25.6%. The global methylation levels were between 0.258 and 0.403. DNA methylation level differences among the six groups were statistic greatly significant (P<0.01). Individual general methylation difference greatly significantly effected on age at first egg, numbers of egg to 20, 32, 36, 43 and 46 weeks old (P<0.01), while it significantly effected on body weight at 6 and 14 weeks (P<0.05). And the correlations among age at first egg and number of egg to main weeks, among old body weight at 6, 8 and 14 weeks, between old body weight at 20 weeks and number of egg to main weeks, old body weight at 14 weeks, old body weight at 18 weeks were statistic greatly significant (P<0.01), while the correlations between number of egg to 20 weeks old and old body weight at 18 weeks, old body weight at 20, 6 and 8 weeks were statistic significant (P<0.05).Single nucleotide polymorphisms of FSHβgene of Jining Bai'ri, Luhua and Laiwu black chickens were comparative studied. The result showed that there was no single nucleotide polymorphism in exon1, one single nucleotide polymorphism in exon3 (A2540C), and twe single nucleotide polymorphisms in intron1 (C712T and A912C). Exon 3 of FSHβwas selected to screen the genomic variation by mean of PCR-SSCP and sequencing in Jining Bai'ri, Luhua and Laiwu black chickens. The result showed that there were three genotypes (AA, BB and AB) in Jining Bai'ri and Luhua chickens, while there was only one genotype in Laiwu black chickens. It was cloned and sequenced to find that the single nucleotide polymorphism was A2540C. Statistic analysis showed that age at first egg of BB genotype of individuals were shorter than AB and AA genotype of individuals, egg number at 43 weeks of AB genotype of individuals were more than AA and BB genotype of individuals, abnormal egg number of AA genotype of individuals were fewer than AB and BB genotype of individuals of Jining Bai'ri chickens, no significant differences were observed in age at first egg, egg number at 43 weeks and abnormal egg number among all genotypes of Jining Bai'ri chickens (P>0.05). While age at first egg of BB genotype of individuals were shorter than AA and AB genotype of individuals, egg number at 43 weeks of AB genotype of individuals were more than AA and BB genotype of individuals, abnormal egg number of AA genotype of individuals were fewer than BB and AB genotype of individuals of Luhua chickens, no significant differences were also observed in age at first egg, egg number at 43 weeks and abnormal egg number among all genotypes of Luhua chickens (P>0.05).
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