The Distribution And Polymorphisms Of CHEMERIN And Its Receptor CMKLR1 Gene In Qinchuan Cattle

Chemerin is a novel adipokine that regulating adipogenesis and adipocyte metabolism as well as immune reaction via its own receptor CMKLR1. Herein, we used qRT-PCR to detect the mRNA expressions of Chemerin gene and CMKLR1 gene in seventeen tissues of three Qinchuan cattle during the experiments. Besides, SNPs in 5'Regulatory Regions, Exons and Intros of Chemerin gene and encoding region of CMKLR1 gene were detected by PCR-SSCP and RFLP in 324 Qinchuan cattle. Additionally, in order to establish the theory of a candidate molecular marker for the beef cattle breeding. Some meat quality traits of Qinchuan catlle with those two genes were also analysed. The results showed as follows:1. Tissue expression profile of Chemerin gene and CMKLR1 gene.The mRNA expressions of Chemerin gene in seventeen different tissues of Qinchuan cattle were detected through qRT-PCR, and the result indicated that bovine Chemerin mRNA was expressed in all tissues, especially highly expressed in the liver, adipose and kidney tissues, and the transcripts of chemerin receptor were widely and highly expressed in several tissues including spleen adipose and kidney tissues. While both of them highly expressed in adipose and kidney tissues.2. Identification of SNPs in Chemerin gene and association with meat quality traits of Qinchuan CattleTwo novel SNPs (868A>G in exon 2 and 2692C>T in exon 5) of Chemerin gene were identified by PCR-SSCP and DNA sequencing technology. Results of the correlation analysis showed that SNP 868A>G had a significant association with the Loin-muscle Area, Back Fat Thickness, Marbling and Water Holding Capability (P<0.05). While also revealed significant effects of genotype on the Backfat Thickness (P<0.05), and Water Holding Capability (P< 0.05) of SNP 2692C>T, while there was no significant effect on the other traits (P>0.05). The results indicated that the polymorphism was significantly associated with some meat quality traits and it could be used as a candidate gene for marker-assisted selection in Qinchuan cattle.3. Identification of SNPs in CMKLR1 gene and association with meat quality traits of Qinchuan CattleUsing PCR-RFLP and DNA sequencing technology, we found two SNPs (264G>C and 762C>T) in the coding region of CMKLR1 gene, and the corresponding detection systems of Asul and xmn1 were established, respective. Results of the correlation analysis showed that both of the SNPs were significantly association with marbling traits of Qinchuan cattle (P<0.05).