Biological Characteristic Research Of The Porcine FSCN1 And TAF7 Genes

In this thesis, my research is divided into two sections, part one is gene structure, SNP detection and traits association of the porcine FSCN1 gene, part two is Cloning, mapping and expression profile of porcine TAF7 gene.Part 1: Gene structure, SNP detection and traits association of the porcine FSCN1 gene. There are differences of growth, carcass and meat quality among different breeds of pig. Viewing from heredity, the phenotype variances of these traits may be caused by the diversity of gene expression during skeletal muscle development. FSCN1 was screened out in the LongSAGE library in our lab. It was expressed in all the prenated skeletal muscle samples at each of the three selected stages (33day, 65day, and 90day). FSCN1 reachs its heghest expression at 65day in Landrace and at 90day in Tongcheng pig. As is known, fascin is actin-bundling protein which contributes to mediate cell adhesion, cell migration and cell interactions. However, the genomic structure and the function of the porcine FSCN1 gene is still unclear. So, we should start the work to uncover it.We have cloned the entire genomic sequence of the porcine FSCN1 gene for the first time, and obtained the 8843bp genomic DNA fragment contains 5 exons and 4 introns, which shares the same structure with the FSCN1 of human and mouse. A total of 32 potential polymorphisms were detected in the porcine FSCN1 gene and three of them were further analyzed. The C/T6840 polymorphism, T allele is dominant in the three mini-pigs (Bama mini-, Wuzhishan mini- and Guizhou mini-pig) but even in other breeds, which is significantly associated with many traits, such as the AGE (the age up to market weght), ADG1 (the average daily gain before on sale), ADG2 (the average daily gain during test period), MpH (meat pH), WaterL (water loss), TENDER (tender) and DripL (drip loss). The A/G7365 polymorphism, G allele is only dominant in Laiwu pigs but A allele in other pigs, which is significantly associated with the traits of SKIN (skin thick), EH (loin eye-muscle height) and MCHC (mean corpuscular hemoglobin concentration). The A/G8462 polymorphism, G allele is even in Landrace but dominant in other breeds, which is significantly associated with five traits, RLF(ratio of lean to fat), HGB (Hemoglobin), MCHC, TP (total protein) and SUN (serum urea nitrogen).Part 2: Cloning, mapping and expression profile of porcine TAF7 gene. The complex of transcription factor TFIID (a complex composed of TATA-binding proteins [TBPs] and TBP-associated factors [TAFs]) serving as general component of the transcription apparatus, play a vital role in regulation cellular RNA polymerase II promoters. TFIID needs different TAF factors depending on the structure of promoter and cell cycle and tissue-specific gene expression requirement. TAF7 is a member of the TAFs familly. Recently, increasing reports revealed that it functions as a transcription factor regulating various biological process. In this study, we have analyzed the molecular characters and the expression profile of the porcine TAF7 gene in order to offer basic knowledge and find molecular marker for breeding and genetics of pig. First, we have cloned and sequenced the porcine TAF7 gene form the Wuzhishan pig sample, the length of which was 1701bp. The porcine TAF7 CDS region was intronless and contains a fragment with the lenth of 1050bp. The network software GENSCAN showed that the porcine TAF7 gene encoded a protein consisted of 349 amino acids, and the net software rpsblast revealed that the porcine TAF7 contained a conserved domain of human TAFII55 (another name of TAF7). Using the software MEGA3.1, we constructed a phylogenetic tree of the TAF7. The result indicated that the porcine TAF7 was most similar to the human TAF7 protein and they both were closed in the Phylogenetic tree.Then, we analyzed the mapping of the porcine TAF7 gene with the IMpRH panel. The result showed that theporcine TAF7 gene was assigned to porcine chromosome 2, closely linked to SW1879 and IL4, the LODs were 6.69 and 6.15 respectively.Finally, we examined the mRNA distribution profile of the porcine TAF7 gene in sixteen adult Wuzhishan pig tissues (heart, dorsal muscles, lymph nodes, spleen, liver, kidney, lung, uterus, testicle, stomach, small and large intestine, ovaries, thymus gland, brain and fat) by semi-quantitative RT-PCR. We found that the porcine TAF7 gene can be detected almost in all tissues, which shows us its ubiquitous functions. Furthermore, the phenomena of high expression in testicle and absent in heart and dorsal muscles need further research.