Sequence characteristics and expression analysis of CYP17A1 and CYP17A2 genes in Chlamys farreri

Abstract CYP17A1 and CYP17A2 genes are members of the CYP17 subfamily and belong to the P450 superfamily. This study analyzed the sequences of Chlamys farreri (C. farreri) CYP17A1 and CYP17A2, found that the CYP17A1 coding sequence (CDS) is 1287 bp, encoding 428 amino acids, and the CYP17A2 coding sequence is 1512 bp, encoding 503 amino acids. The two genes both contain three conserved regions: the Ozols' tripeptide region, the heme binding region, and the Ono sequence which is unique to CYP17 subfamily, and these regions are conserved in different species by the homology analysis of multiple amino sequence. Semi-quantitative RT-PCR (SqRT-PCR) showed that CYP17A1 was strongly expressed in the kidney and hepatopancreas of females, strongly expressed in the hepatopancreas of males, and weakly expressed in other tissues. CYP17A2 was strongly expressed in the kidney and gill of females, in the adductor muscle, kidney, gill and testis of males, weakly expressed in other tissues. The wide expression of CYP17A1 and CYP17A2 in C. farreri suggest that they may play multiple roles in different tissues.Using real-time fluorescent quantitative PCR (qPCR), the expression during gametogenesis was detected, CYP17A1 was expressed highest at the ovarian growth stage., it was considered the gene may play a role in oocytes growth, furthermore, we speculated that the gene may affect oocyte growth by participating in production of estradiol. CYP17A1 expression increased with the testis development, which implied this gene may be involved in the testosterone’ production. CYP17A2 expressed highest in testis at mature stage, it was believed that this gene may affect sperm excretion and motility by participating in pregnancy hormones production. CYP17A2 expressed higher in the ovary at mature stage than other stages, it is speculated that this gene may play a role in oocytes maturation by participating in 17α, 20β-DP (17α, 20β-dihydroxy-4-pregnen-3-one, DHP, a kind of progesterone) production.