Comparative Studies on Duplicated foxl2 Paralogs in Spotted Knifejaw Oplegnathus punctatus Show Functional Diversification.

As a member of the forkhead box L gene family, plays a significant role in gonadal development and the regulation of reproduction. During the evolution of deuterostome, whole genome duplication (WGD)-enriched lineage diversifications and regulation mechanisms occurs. However, only limited research exists on duplication in teleost or other vertebrate species. In this study, two paralogs, and , were identified in the transcriptome of spotted knifejaw (), which had varying expressions in the gonads. The was expressed higher in the ovary, while was expressed higher in the testis. Phylogenetic reconstruction, synteny analysis, and the molecular evolution test confirmed that and likely originated from the first two WGD. The expression patterns test using qRT-PCR and ISH as well as motif scan analysis revealed evidence of potentially functional divergence between the and paralogs in spotted knifejaw. Our results indicate that and may originate from the first two WGD, be active in transcription, and have undergone functional divergence. These results shed new light on the evolutionary trajectories of and and highlights the need for further detailed functional analysis of these two duplicated paralogs.