Association of NLK polymorphisms with intramuscular fat content and fatty acid composition traits in pigs

Nemo-like protein kinase (NIX) is a key enzyme in the noncanonical Wnt signaling pathway and it is involved in adipogenesis. In this study, the associations of the polymorphisms of the NLK gene with intramuscular fat (IMF) content and fatty acid (FA) composition traits were analyzed in crossbred commercial pigs. Three single nucleotide polymorphisms (SNPs) of the porcine NLK gene were identified in 5'-flanking region and introns, consisting of g.403739_403764insdel, g.574462T>C and g.630426A>G. The NLK g.403739_403764insdel was significantly associated with IMF content and palmitoleic acid levels. No association of the NLK g.574462T>C SNP with IMF content was observed. However, this SNP was significantly associated with arachidic and eicosenoic acid levels. Moreover, the NLK g.630426A>G SNP was significantly associated with IMF content and the fatty composition of arachidic, linoleic, as well as polyunsaturated FA and omega 6 FA levels. These results indicate the importance of porcine NIX as a candidate gene for porcine IMF content and fatty acid composition traits. (C) 2016 Elsevier Ltd. All rights reserved.