Genetic variations and polymorphisms for porcine Myostatin and IGF-2 genes related to growth, carcass and reproductive traits

• Main Authors: Yi-Ting Chen, 陳薏婷
• Other Authors: 王佩華
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/40783012266437875455

碩士 === 國立臺灣大學 === 動物科學技術學研究所 === 102 === Myostatin (MSTN), a member of transforming growth factor-β (TGF-β) superfamily, is a negative regulator of muscle development. Loss-of-function of MSTN protein resulted in double-muscled phenotype in several mammalian species, such as cattle, sheep, human, and dog have been found. However, there was no functional mutation in porcine MSTN gene. Therefore, there was no so-called double-muscled breed of pig. The aim of this study was to investigate the effects of polymorphisms of MSTN and IGF-2 genes on porcine growth performance, carcass, and reproductive traits. DNA from purebred and crossbred pigs were extracted, including 1,743 Duroc, 944 Landrace, and 343 Yorkshire for growth performance analysis; 270 Duroc × Landrace (DL) and 153 Duroc × Yorkshire × Landrace (DYL) for carcass traits analysis; 528 Landrace sows for reproductive performance analysis. Data of average daily gain (ADG), feed efficiency (FE), ultrasound backfat thickness (BF), body weight at 70 days-old (BW70) and 150 days-old (BW150), days to 110 kg of body weight (D110 kg), longissimus muscle area (LMA) at 10th rib, carcass backfat thickness, meat and fat weight in the anterior, middle, and posterior cuts of carcass, total lean weight and percentage, and total number born (TNB) and number of born alive piglets (NBA) of each parity were collected. Two SNPs (g.435G>A and g.447A>G) in the promoter region of MSTN gene and one SNP (g.162C>G) in the intron 7 of IGF-2 gene were genotyped using Taqman SNP Genotyping Assay. The association results indicated that the MSTN g.435GG/447AA individuals had better ADG, heavier BW150, and lower Age110kg (P<0.05) in Duroc pigs; better ADG (P<0.05) in Landrace pigs; greater ADG and BW150, and lower BF and Age110kg (P<0.1) in Yorkshire. The IGF-2 g.162CC individuals had better BW70, and thinner BF (P<0.1) in Yorkshire pigs. The IGF-2 g.162GG individuals were found to have significant thicker backfat at 10th and last rib (P<0.05), and higher fat weight in the anterior cuts of carcass (P<0.1) in DL and DYL crossbred pigs. Additionally, there were no significant interactions between MSTN g.435/447 and IGF-2 g.162 on growth performance and carcass traits. In Landrance sow’s reproductive trait showed that there were no significant difference between the genotype of MSTN g.435G>A/447A>G and the TNB or NBA observations. In conclusion, these two loci are potential genetic markers in porcine selection of growth performance and carcass traits, and they could be used independently. Selection for MSTN g.435G/447A allele is expected to increase body weight and growth rate in Duroc and Yorkshire pigs. Furthermore, selection for IGF-2 intron 7 g.162C allele is expected to increase body weight and decrease fat accumulation in Yorkshire, DL and DYL pigs. However, the genotype of MSTN g.435/447 might not affect the litter size in Landrace sows.