Identification of genes associated with carotenoids accumulation in scallop (Patinopecten yessoensis)

Carotenoids are key nutrients and common pigments for marine species, but the underlying mechanism of carotenoids bioavailability is unclear. In this study, genome-wide association study (GWAS) was performed for pectenolone and pectenoxanthin content in the adductor muscle of "Haida golden scallop", a variety for Yesso scallop (Patinopecten yessoensis), which was characterized by orange adductor muscle enriched in carotenoids. The most significant SNP was the same for both pectenolone and pectenoxanthin, which was located upstream of two tandem Poly(ADP-ribose) polymerases (PARPs), PARP9/14/15-1 and PARP9/14/15-2. The expression levels of these two PARPs were significantly correlated with the concentrations of pectenoxanthin and pectenolone, respectively. Three other SNPs significantly associated with the concentrations of ketocarotenoid pectenolone were also detected, among which, two were located around another two PARPs (PARP9/14/15-3 and PARP9/14/ 15-4), and a significant correlation was found between PARP9/14/15-3 expression and pectenolone concentrations; one SNP was near the cluster of Cytochrome P450 2J6 (CYP2J6), a P450 subfamily which has been reported to catalyze ketocarotenoid production. Our data imply the involvement of PARP9/14/15s in carotenoids accumulation and CYP2J6s in pectenolone conversion in scallop.