Association and expression analysis of porcine ACLY gene related to growth and carcass quality traits in Italian Large White and Italian Duroc breeds

Lipogenesis is a complex metabolic process that involves many enzymes: one of them, ATP citrate lyase (ACLY) is related in fatty acid biosynthesis. The aim of this study was to find association between two Single Nucleotide Polymorphisms for ACLY porcine gene and the most important productive traits and to verify the expression level of this gene in Italian Large White and Italian Duroc pigs in muscle and backfat tissues. The first SNP ACLYc.NM_001105302 2956T>C lies in a portion of the coding region corresponding to human exon 25 while the second SNP ACLY c.*523T>C is located in the porcine ACLY gene 3' UTR. In Italian Large White pigs SNP ACLYc.NM_001105302 2956T>C shows an association with Average Daily Gain, and CC genotype is the most favourable to animal growth, whereas the same SNP in Italian Duroc pigs is not associated with the analysed traits. This difference in association results may be a plausible evidence of the divergent genome background between Italian Large White and Italian Duroc breeds, as reported in recent studies. On the other hand c.*523T>C SNP shows concordant association results, as in both breeds CC animals display the best values for the analysed carcass traits. Moreover, we evaluated in both breeds ACLY gene expression level in skeletal muscle and backfat. According to their elevated marbling, Italian Duroc pigs have the highest ACLY gene expression in muscle, while Italian Large White pigs present the highest transcription level in backfat tissue. Furthermore ACLY expression is not influenced by the two studied polymorphisms, suggesting that these mutations do not affect gene transcription but might be in linkage disequilibrium with the causal mutation. In conclusion ACLY might be considered as new biomarker for genetic improvement schemes aimed to modulate the fat content, in carcass and in muscle.