Isolation, Radiation Hybrid Mapping Of Porcine Genes Related To Adipocyte Differentiation And Fat Deposition And Their Genetics Effect

Adipose tissue is differentiated highly. It appears on the late stage of embryo development, and grows rapidly after birth. Increase of number of new adipocytes and the volume of adipocytes are involved in adipose tissue development. AEBP1 is a transcriptional repressor found in the research on obesity of mouse. A region within the aP2 gene proximal promoter termed AE-1 contains a site recognized by AEBP1, and the expression of the protein encoded by aP2 is considered to be a marker for adipocyte differentiation. There are two transcripts AEBP1/ACLP found in mouse AEBP1 gene, and the functions of AEBP1 and ACLP protein are different. The sequence, structure and function of porcine AEBP1 gene have not been reported at present. In this research, the sequencing of cDNA and DNA of porcine AEBP1 gene, and bioinformatics analysis of the gene sequences among different pig breeds were first performed. Fine chromosomal localization of AEBP1 gene was determined by INRA-Minnesota porcine radiation hybrid panel (IMpRH) mapping. RT-PCR was used for detecting whether there are different transcripts by alternative splicing the mRNA of AEBP1 gene. The deduced amino acids encoded by different transcripts were analyzed by bioinformatics, and the expression profile research on different transcripts was also investigated.To confirm the genetic effects of AEBP1, PPARγ related to porcine adipocyte differentiation, MC4R, MC5R and IGF2 to fat deposition, and PPKAG3 to intramuscular fat, these candidate genes were genotyped by using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Screening for polymorphisms in these genes was performed in 626 pigs established in Huazhong Agricultural University, containing three purebreds of Large White (LW), Landrace (L), and Meishan (MS) pig breeds slaughtered in the year of 2002, four crossbreds of Large White×Landrace (LW×L), Landrace×Large White (L×LW), Large White×Meishan (LW×MS) and Meishan×Large White (MS×LW) pigs slaughtered in 2002, and the LW×MS F₂ resource population slaughtered in 2003 and 2004. The association studies were also performed between the genotypes and traits of carcass and meat quality, including backfat thickness, intramuscular fat content and so on. In addition, partial DNA of porcine ADD1 gene, the candidate gene for porcine adipocyte differentiation, was sequenced and compared among different pig breeds. The main results are as follows:1. Isolation, sequencing and sequence analysis of the cDNA and DNA fragment of porcine AEBP1 gene: Based on the BLAST result of comparing the nucleotides of human AEBP1 gene against pig EST database in NCBI, a set of high matched pig ESTs were...