Characterization of Two Gonadal Genes, zar1 and wt1b, in Hermaphroditic Fish Asian Seabass (<i>Lates calcarifer</i>)
Han Cui,
Haoyu Zhu,
Wenzhuo Ban,
Yulin Li,
Ruyi Chen,
Lingli Li,
Xiaoling Zhang,
Kaili Chen,
Hongyan Xu
Affiliations
Han Cui
Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City, College of Fisheries, Southwest University, Chongqing 402460, China
Haoyu Zhu
Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City, College of Fisheries, Southwest University, Chongqing 402460, China
Wenzhuo Ban
Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City, College of Fisheries, Southwest University, Chongqing 402460, China
Yulin Li
Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City, College of Fisheries, Southwest University, Chongqing 402460, China
Ruyi Chen
Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City, College of Fisheries, Southwest University, Chongqing 402460, China
Lingli Li
Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City, College of Fisheries, Southwest University, Chongqing 402460, China
Xiaoling Zhang
Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City, College of Fisheries, Southwest University, Chongqing 402460, China
Kaili Chen
Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City, College of Fisheries, Southwest University, Chongqing 402460, China
Hongyan Xu
Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City, College of Fisheries, Southwest University, Chongqing 402460, China
Zygote arrest-1 (Zar1) and Wilms’ tumor 1 (Wt1) play an important role in oogenesis, with the latter also involved in testicular development and gender differentiation. Here, Lczar1 and Lcwt1b were identified in Asian seabass (Lates calcarifer), a hermaphrodite fish, as the valuable model for studying sex differentiation. The cloned cDNA fragments of Lczar1 were 1192 bp, encoding 336 amino acids, and contained a zinc-binding domain, while those of Lcwt1b cDNA were 1521 bp, encoding a peptide of 423 amino acids with a Zn finger domain belonging to Wt1b family. RT-qPCR analysis showed that Lczar1 mRNA was exclusively expressed in the ovary, while Lcwt1b mRNA was majorly expressed in the gonads in a higher amount in the testis than in the ovary. In situ hybridization results showed that Lczar1 mRNA was mainly concentrated in oogonia and oocytes at early stages in the ovary, but were undetectable in the testis. Lcwt1b mRNA was localized not only in gonadal somatic cells (the testis and ovary), but also in female and male germ cells in the early developmental stages, such as those of previtellogenic oocytes, spermatogonia, spermatocytes and spermatids. These results indicated that Lczar1 and Lcwt1b possibly play roles in gonadal development. Therefore, the findings of this study will provide a basis for clarifying the mechanism of Lczar1 and Lcwt1b in regulating germ cell development and the sex reversal of Asian seabass and even other hermaphroditic species.
