AUTHOR=Yan Susu , Xu Mengge , Xie Jing , Liao Xiaoting , Liu Meimei , Wang Siting , Fan Sishao , Dong Zhiguo 

TITLE=Characterization, expression profiling, and estradiol response analysis of DMRT3 and FOXL2 in clam Cyclina sinensis

JOURNAL=Frontiers in Marine Science

VOLUME=10

YEAR=2023

URL=https://www.frontiersin.org/journals/marine-science/articles/10.3389/fmars.2023.1120015

DOI=10.3389/fmars.2023.1120015

ISSN=2296-7745

ABSTRACT=<p>The clam <italic>Cyclina sinensis</italic> is one of the important economical aquaculture shellfish in China. However, the mechanisms of sex determination and differentiation in <italic>C. sinensis</italic> have not been fully studied. In this study, full-length cDNAs of <italic>DMRT3</italic> and <italic>FOXL2</italic> were cloned and functionally characterized. The ORF region of <italic>CsDMRT3</italic> consists of 1137 nucleotides, which encode 378 amino acids contains a conserved DM domain of <italic>DMRT</italic> family. The ORF region of <italic>CsFOXL2</italic> is 1245 bp, encodes 414 amino acids, and contains a conserved FH domain. Tissue-specific expression results showed that the higher expression level of <italic>CsDMRT3</italic> and <italic>CsFOXL2</italic> was found in the ovary and testis of <italic>C. sinensis.</italic> The expression levels of <italic>CsDMRT3</italic> and <italic>CsFOXL2</italic> also peaked at the maturation stage of male and female gonadal development, respectively. Moreover, the expression levels of <italic>CsDMRT3</italic> and <italic>CsFOXL2</italic> were significantly higher in the trochophore and D-larval stages than in other stages. The transcript levels of <italic>CsDMRT3</italic> reached the highest level at 11 months of age, while the <italic>CsFOXL2</italic> reached the highest level at 7 months of age. In estradiol-treated experiments, the expression levels of <italic>CsDMRT3</italic> and <italic>CsFOXL2</italic> in the gonads were highest at 5 µg/L estradiol treatment, and histologically, it was observed that the oocytes diameters became larger with increasing estradiol concentration. These results suggest that <italic>CsDMRT3</italic> and <italic>CsFOXL2</italic> play an important role in gonadal development and sex differentiation of <italic>C. sinensis</italic>.</p>