Selection, Identification And SNP Analysis Of Correlation Genes With Cashmere Growth On Cashmere Goats

Cashmere goat is a kind of economic animal for production cashmere,which cashmere growth have strong seasonal and great difference between different breeds,which can’t produce cashmere for most of cahsmere goats in the telogen period（May-August）, while some strains of Liaoning cashmere goats can product cahsmere in the whole year（beginning from June）. Embedding melatonin can promote cashmere growth in the telogen period so as to production cashmere in the whole year.In this paper,Inner Mongolian Ardrs white cashmere goats were used as main experimental samples, selection of candidate and differentially expressed genes was engaged in studying differentially expressed gene between genetic polymorphism of production cashmere economic traits and skin organism embedding melatonin in the telogen period by PCR-SSCP and gene chip technology, and preliminary discuss factors and molecular regulation mechanism of promoting cashmere growth.1、SNP analysis of endocrine hormone gene on cashmere goats456samples were used as experimental materials including four types:Inner Mongolian Ardrs, Alashan, Erlangshan and Hanshan white cashmere goats by PCR-SSCP and DNA sequencing technology to analyze16loci genetic polymorphism of6candidate genes including PRL、PRLR、MLTR1a、MLTR1b、IGF-I and TG.Results were as follows:（1）There were SSCP at P2primer of PRL gene and P3primer of PRLR gene. P2primer of exon5of PRL gene existed in C-A mutation at X76049:g.576bp, which resulted in CCC-ACC of the176th codon from Pro into Thr. The results showed that the its SNP was the most significant correlation with cashmere thickness（P<0.01）, and the marginal significant correlation（P=0.055）with kidding number of Ardrs cashmere goat; P3primer was in T-C mutation at HQ266606:g of exon10of PRLR gene, which lead to CTT-CCT of the359th codon from Lue into Pro, of which SNP was significant difference （P<0.05） to cashmere fineness.（2） There were SSCP in the exon2of MLTRlb gene and three of SNP were detected. P8primer existed in C-G mutation at NM₀01206907:g.648bp which didn’t result in change of amino acid, and also be G-A mutation at NM₀01206907:g.665bp which led to CGC-CAC of the223th codon from Arg into His. The results showed that the SNP of P8locus had an significant effect on cashmere yield（P<0.05）, meanwhile, interaction effect between the SNP genotype and age was a significant correlation with cashmere thickness（P <0.05）; P9primer existed in G-A mutation at NM₀01206907:g.1015bp, which led to GGC-AGC of the339th codon from Gly into Ser. The analysis indicated that interaction effect of the SNP and age was the marginal significant correlation（P=0.056） with cashmere fineness.（3） There were SSCP at P14primer and P16primer of TG gene. P14primer of the exon9existed in C-T mutation at NM₁73883:g.1895bp, which resulted in GCG-GTG of the632th codon from Ala into Val. P16primer of exon11existed in G-A mutation at NM₁73883:g.2849bp, which led to CGC-CAC of the950th codon from Arg into His, which both were no significant effect on weight, kidding number and production cashmere traits （p>0.05）. P8and P9primes were not significance（P>0.05） with kidding number and birth weight.2^Selection, identification and characteristic analysis of skin differentially expressed gene on cashmere Goat（1） To select correlation genes which promoted cashmere growth embedding melatonin（MLT） in the telogen period by gene chip technology.To have selected95of differentially expressed genes,61of which were up-regulated expression, while34genes were down-regulated expression.Those abnormal expression genes were assorted by function,18.33%,47.78%,33.89%of genes involved in cellular component, molecular function, biological process, respectively.（2） Analyses of signaling pathway showed that differentially expressed genes totally involved in55pieces of signaling pathway. CTNNB1gene participated in WNT signaling pathway, and CYP2B gene related to metabolism of retinol and xenobiotics by cytochrome P450, which probably promoted cashmere growth and follicle development related with embedding MLT in the telogen period.（3） Significant Up-regulated PAX6gene and down-regulated CSN2gene of differentially expressed gene were further identified by real time quantitative so as to validate result of gene chip. Resulted showed that expression level of skin in PAX6gene was2.399times that of control group, and also expression level of skin in CNS2gene was0.044times compared to control group. The results were the same with gene chip. It indicated that gene chip had character of data precision and reliability.The paper disclosed that CTNNB1gene, CYP2B gene, PAX6gene and CSN2gene etc. probably participated in promoting cashmere growth process after embedding MLT, which was necessary to further study their gene function, so as to find out molecular mechanism of cashmere growth and follicle development on cashmere goats.