Characterization of a long-chain fatty acid-CoA ligase 1 gene and association between its SNPs and growth traits in the clam Meretrix meretrix

• A long-chain fatty acid-CoA ligase gene was cloned in Meretrix meretrix.
• Expression of MmeACSL1 had a significant increase under starvation.
• Five SNPs and their haplotypes were found to be associated with growth traits.

Long-chain fatty acid-CoA ligases (ACSLs) play crucial roles in fatty acid (FA) metabolism. They convert free long-chain FA into acyl-CoAs, which are key intermediates in both anabolic and catabolic pathways. A long-chain fatty acid-CoA ligase gene was cloned in the clam Meretrix meretrix (MmeACSL1), with a full-length cDNA of 1865 bp encoding 475 amino acids. Its expression was only detected in hepatopancreas by semi-quantitative reverse transcription PCR. Expression level of MmeACSL1 exhibited a significant increase in a starvation experiment (P < 0.05). This indicates that MmeACSL1 plays an important role in normal metabolism of M. meretrix and may be involved in energy supply and storage. Two exon SNPs and six intron SNPs were developed in this gene by direct sequencing. A marker-trait association analysis showed that five of these SNPs were significantly associated with growth traits (P < 0.05). Also, haplotypes comprised of the five SNPs were revealed to be significantly growth-related (P < 0.05), which further corroborates the relationship of this gene to growth traits of M. meretrix.