Genome-wide association analysis reveals genetic loci and candidate genes associated with intramuscular fat in Duroc pigs

Intramuscular fat(IMF) is a major meat-quality trait in pigs. The content of IMF is directly associated with the taste and flavor of pork. As a complex trait, there could be multiple genes affecting IMF content in pork. Genomewide association study is a powerful tool to detect genomic regions associated with phenotypic variations. The objectives of the present study were to identify or refine the positions of genomic regions affecting IMF, and to characterize candidate genes and pathways that may influence this trait. Of note, we identified a significant region in longissium dorsi muscle in a Duroc pig population for IMF content with Porcine SNP60 v2 Bead Chip. This region spans 1.24 Mb on chromosome 8 and had been identified as a quantitative trait locus for IMF in Pietrain, Large White, Landrace, and Leicoma pigs. In this region, eight SNPs were significantly associated with IMF content. Three genes proximal to these significant SNPs were considered candidate genes, including ZDHHC16, LOC102162218 and PCDH7. Our results confirm several previous findings and highlight several genes that may contribute to IMF variation in Duroc pigs.

Effects of enucleation method on in vitro and in vivo development rate of cloned pig embryos

Enucleation is a crucial procedure for mammalian somatic cell nuclear transfer(SCNT), especially for domestic animal cloning. Oocytes of domestic animals such as pigs and cattle contain dark lipid droplets that hinder localization and removal of the nucleus. Using an oocyte enucleation technique that can obtain a high enucleation rate but has minimal negative effects on the reprogramming potential of oocyte for cloning is bene?cial for enhancing the outcome of SCNT. In this study, we compared the pig cloning ef?ciency resulting from blind aspiration-based(BA-B) enucleation and spindle imaging system-assisted(SIS-A) enucleation, and compared the pig SCNT success rate associated with BA-B enucleation and blind aspiration plus post-enucleation staining-based(BAPPS-B) enucleation. SIS-A enucleation achieved a signi?cantly higher oocyte enucleation success rate and tended to obtain a higher in vivo full term development rate of SCNT embryos than BA-B enucleation. BAPPS-B enucleation also obtained signi?cantly higher in vitro as well as in vivo full term development ef?ciency of cloned porcine embryos than BA-B enucleation. These data indicate that SIS-A and BAPPS-B enucleation are better approaches for pig SCNT than BA-B enucleation.