Transcription of Dynein Heavy Chain 9 (DNAH9) in Paralichthys olivaceus: Insights into the Evolution of the DNAH9 Gene.

As induced by the loss of prologues or irrelevant parts added in sequences, gene duplicates affect evolution. Following fish specific genome duplication (FSGD), gene duplicates undergo divergent pathways in gene evolution. Our aim is to map the evolution process of DNAH9 duplication in Paralichthys olivaceus (P. olivaceus) after FSGD to gain an insight into the evolution pathway in teleostes. In this study, two duplicates (DNAH9A and DNAH9B) and two transcripts (dnah9a and dnah9b) were identified in P. olivaceus. A comparison of each genomic duplicate with each transcript DNAH9B could transcribe a complete transcript, dnah9b, but DNAH9A was necessary to co-transcribe DNAH9B with dnah9a. From phylogenetic trees, the DNAH9 type of P. olivaceus shared the same cluster with all ray-finned fishes. However, DNAH9 duplicates only occurred in P. olivaceus and Cynoglossus semilaevis. In conclusion, the duplication of P. olivaceus DNAH9 occurred during FSGD, and the duplicates showed a divergent evolution path, undergoing a period of duplication-degeneration-complementation and then obtaining a new function. [ABSTRACT FROM AUTHOR]