Isolation, Expression Pattern, Polymorphism and Association Analysis of Porcine TIAF1 Gene

Y Wang,Z Q Ren,Y Z Xiong,B Zuo,C Y Deng,M G Lei

doi:10.5713/ajas.2009.80400

Abstract

TIAF1 is a TGF-β1-induced anti-apoptotic factor that plays a critical role in blocking TNF (tumor necrosis factor) cytotoxicity in mouse fibroblasts and participates in TGF-β-mediated growth regulation. In this study, we obtained the full-length cDNA sequence of the porcine TIAF1 gene. Real-time PCR further revealed that the TIAF1 gene was expressed at the highest level in liver and kidney with prominent expressions detected in uterus, and lower levels detected in heart, spleen, lung, stomach, small intestine, skeletal muscle and fat of White pigs. Sequence analysis indicated that a 6 base-pair deletion mutation existed in the exon of the TIAF1 gene between Meishan and White pigs. This mutation induced deletion of Gln and Val amino acids. PCR-RFLP was used to detect the polymorphism in 394 pigs of a Large WhitexMeishan F 2 resource population and four purebred pig populations. The frequencies of the A allele (with a 6 bp deletion) were dominant in Chinese Meishan and Bamei pigs, and the frequencies of the B allele (no 6 bp deletion) were dominant in White and Landrace pigs. Association analyses revealed that the deletion mutation had highly significant associations (p<0.01) with meat marbling score of the thorax-waist longissimus dorsi (LD) muscle (MM1) and intramuscular fat percentage (IMF), and significant associations (p<0.05) with carcass length (CL). The results presented here supply evidence that the 6 bp deletion mutation in the TIAF1 gene affects porcine meat quality and provides useful information for further porcine breeding.

Highlights

Some studies have indicated that there is significant phenotypic variance between Chinese indigenous pigs and Western pigs
Meishan pigs (Chinese indigenous pigs) have lower lean meat content in their carcasses compared to Large White pigs (Western pigs), but the lean meat of Meishan pigs is of better quality (Serra et al, 1992)
Spatial expression pattern of the TIAF1 gene The spatial expression analysis showed that the TIAF1 gene was expressed at the highest level in liver and kidney with prominent expressions detected in uterus, and lower levels detected in heart, spleen, lung, stomach, small intestine, skeletal muscle and fat of Large White pigs (Figure 3)

Summary

INTRODUCTION

Some studies have indicated that there is significant phenotypic variance between Chinese indigenous pigs and Western pigs. Analysis of semi-quantitative RT-PCR found that EST167 presented higher expression in the liver of Meishan pigs, but lower in Large White pigs This was approximately consistent with the result of mRNA differential display (Figure 1(B) and (C)). Polymorphism detection and allele frequencies The primer pair Ct4F⁄Ct4R amplified a total of 601 bp of the porcine TIAF1 gene from four different individuals (two Large White pigs and two Meishan pigs) Comparison of those sequences revealed a 6 base-pair deletion mutation from 1,001 bp to 1,006 bp in the exon (GenBank accession No EU872207) which caused Gln and Val amino acid deletion; further analyses of the deletion mutation were carried out using the restriction fragment length polymorphism (RFLP) method by the restriction enzyme Eco I. The genotypes are shown at the top of the lanes, M, Marker DL2000 DNA Ladder (2,000 bp, 1,000 bp, 750 bp, 500 bp, 250 bp, 100 bp) (TaKaRa)

AA AB BB

Findings

DISCUSSION