The Association Of Polymorphism, Methylation Status Of BMP-4with Carcass Traits For Rabbit

BMP-4(bone morphogenetic proteins-4) which belongs to TGF-β plays an important role in growth and development of mammals, especially in the process of bone growth. This study discussed the association of methylation status of BMP-4promoter with heterosis by detecting polymorphism and methylation status of BMP-4, which aimed to supply a theoretical reference for the reasonable use of BMP-4gene as a molecular marker. In addition, this essay also focused on the relationship between methylation of BMP-4promoter region and heterosis during the breeding of rabbit production traits.1. Under the research, we obtained the complete CDS of rabbit BMP-4gene and compared it with human, mouse, rat, cattle, sheep and sus scrofa. The results showed that their homology were94.5%,91.2%,91.2%,93.7%,93.9%,93.7%respectively, indicating that the genes of different species kept high conservation in evolution process.The polymorphism of BMP-4gene full-length CDS region in different rabbit populations were detected, respectively. According to the sequencing and sequence alignment, we found that C91T was a silent mutation (alanine) in coding region at BMP4.2-1locus. Two genotypes (wild type and heterozygous type) were found, but only3samples belonging to Heterozygous type. The results showed that7rabbit populations were represented low diversity at BMP4.2-1locus and their polymorphic information content were uniformity. However, no polymorphism had been found at other loci. What the reason probably was that BMP-4was highly conservative during the evolutionary process and the natural and artificial selection pressure had little effect on it.2. In this study, we examined the methylation status of part CpG of BMP-4promoter in4rabbit populations, which were New Zealand white rabbit, Fujian yellow rabbit and their reciprocal cross populations, accounting for80samples. As a results, methylation were found in the promoter sequence. Slaughter traits were variable under different methylation level. Hwoever, they did not match very well with methylation level, which may be caused by the methylation state of specific site.Based on MSP, we did further research by BSP. Consequently, the methylation was found at the fifth CpG locus of the sequence in Fujian Yellow Rabbit, while the fifth locus methylation was no found in the other three populations. Besides, there were two binding sites at the fifth CpG locus, which were ADR1binding site(CGAGC) and RAF binding site(CCGA). In addition, If methylation occurred at the locus, the binding efficiency of RAF and ADR1with cis-acting element decreased, leading to the reduction of the expression of BMP-4. Otherwise, smoothly combining RAF and ADR1with cis-acting element promoted the expression of BMP-4.