Sexually Dimorphic Expression and Special Regulatory Sequence of Dnali1 in the Olive Flounder Paralichthys Olivaceus

Abstract Dynein axonemal light intermediate chain 1 (dnali1) is an important part of axonemal dyneins and plays an important role in the growth and development of animals. However, there is little information about dnali1 in fish. Herein, we cloned dnali1 gene from the genome of olive flounder (Paralichthys olivaceus), a commercially important maricultured fish in China, Japan, and Korea, and analyzed its expression patterns in different gender fish. The DNA sequence of the entire gene contained a 771 bp open reading frame (ORF), two different sizes of 5' untranslated region (5'UTR), and a 1499 bp 3' untranslated region (3'UTR). Two duplicated 922 nt fragments were found in dnali1 mRNA. The first fragment contained the downstream coding region and the front portion of 3'UTR, and the second fragment was entirely located in 3’UTR. Multiple alignments indicated that the flounder Dnali1 protein contained the putative conserved domain. Its expression showed sexually dimorphic with predominant expression in the flounder testis, and lower expression in other tissues. The gene with the larger 5’UTR was specifically expressed in the testis. The highest expression level in the testis was detected at stages Ⅳ and Ⅴ. Transient expression analysis showed that the 922 bp repeated sequence 3’UTR of dnali1 down-regulated the expression of GFP at the early stage in zebrafish. The results implied that dnali1 might play an important role in flounder testis, especially in the period of spermatogenesis, and the 5’UTR and the repetitive sequences in 3’UTR might contain some special regulatory elements for the cilia.