Study On The Relationship Between BNC2 Gene Polymorphisms And White Earlobe Traits,Egg Production Traits In Chicken

BNC2 is present in virtually every cell type and its function is likely to be related to RNA splicing. BNC2 is thought to act a transcription factor that maintains the proliferative capacity of keratinocytes and prevents their terminal differentiation. More recently, BNC2 gene has been identified as the gene controlling the chicken skin pigmentation, and participated in the mouse ovaries. Here, BNC2 as candidate gene, our study was performed to show that the associations of its polymorphisms with chicken white earlobe traits and egg production traits. The main results were as follows:1. Three variant transcripts of chicken BNC2 gene was obtained by PCR method, in which the first one was 3020 bp in length, the second one was 1066 bp in length and the third one was 866 bp in length, and all were located on open reading frame.2.Analysis of the function structure of the BNC2 protein domain, found that the structure of the domain was Atrophin-1, and the protein didn't across the membrane area.The chicken BNC2 was made a homologous for evolution analysis with zebrafish, turquoise killifish, cow, panda, dog and animals, we found that it was closest to Chinese hamster,zebrafish, turquoise killifish, and they belonged to the same branch, in addition it was far away from giant panda, dog, rhesus monkey, norway rat and house mouse.3. RT-PCR demonstrating BNC2 was expressed in chicken tissues including liver,lung, kidney, hypothalamus, ovarian, ear and beside others. BNC2 was predominantly expressed in lung, hypothalamus and ovarian, and with low level in liver and kidney.Moreover in comparison of BNC2 gene in normal earlobe chicken with white earlobe chicken, the normal earlobe chicken expression of BNC2 gene was increased significantly(about 4 folds higher), than that of the white earlobe individuals.4. To Qingyuan Ma Ji BNC2 gene sequenced for screening polymorphism, wediscovered 20 SNPs. In addition we identified the relationship12 SNPs in the 5' flank of the gene with white earlobe traits and egg production traits, it showed that g.366A>T locus and g.3411G>A locus were significantly related to the earlobe(P<0.05). Whereas,g.1600A>G locus was significantly related to egg production(P<0.05).As indicated above, we cloned the BNC2 gene and obtained three variant transcripts by PCR method, and it was expressed in chicken tissues including liver, lung, kidney,hypothalamus, ovarian, ear and beside others, and its polymorphism may be related to white earlobe and egg production.