Studie On The SNP Of The Chicken's Prolactin Gene

The chicken's prolactin(PRL) gene has a very important effect in the development of chicken broodiness behaviour. The objective of this research is to find the Single Nucleotide Polymorphisms(SNP)in PRL gene.Four types of chickens,52 Abor Acres broilers(AA),48 Silkies, 51 White Leghorn,and 46 Hyline Brown were used as the material in this research. The genomic DNA is extracted by the traditional method of phenol. Based on the complete DNA sequence of PRL (AF288715), six pairs of primers to amplify the five exons (1,2,3,4,5 ) and one intron (intron 2) fragment were designed respectively.SSCP analysis was commanded on these six PCR products and the polymorphisms were found in the fragment of exon2,exon5 and intron2.The result of sequencing shows that there are two SNPs site in the fragment of exon5 ,locating respectively at 8052bp (T-C)and 8113bp(G-C),but the variation of DNA has not changed amino acid encoded, and no mutation was found in the coding domain of exon2 fragment. Seven SNPs were found in intron2 and in the same time one nuclear insertion site was found. The T-G mutation at 4171 bp leads a new HaeIII site and the analysis with HaeIII verified that there exist polymorphism at this new restriction endonuclease enzyme site and a PCR-RFLP procotocol was designed to genotype this site .It is showed that the result of the PCR-RFLP is completely coincident with that of the PCR-SSCP.The genotype frequencies and the gene frequencies were calculated among these four stocks and there were significant difference in gene frequencies between these stocks.