Characterization and gonadal expression of FOXL2 relative to Cyp19a genes in spotted scat Scatophagus argus

• The full length of FOXL2, Cyp19a1a and Cyp19a1b was obtained.
• qPCR was used to quantify FOXL2, Cyp19a1a and Cyp19a1b transcript levels.
• Location of FOXL2 gene in the ovary and testis was detected by ISH.
• FOXL2 expression deceased gradually with gonadal development.
• Cyp19a1a and Cyp19a1b were expressed coordinately with FOXL2.

In the present study, we cloned the full-length cDNAs of FOXL2, Cyp19a1a and Cyp19a1b and analyzed their expression patterns during gonadal development in spotted scat, Scatophagus argus. All three genes were expressed in ovaries and testes but showed sexual dimorphism. At early stages of gonadal development, the expression of FOXL2 in ovaries was higher than testes. FOXL2 expression deceased gradually as gonadal development continued, and reached the lowest level at the mature stage. Cyp19a1a and Cyp19a1b were expressed coordinately with FOXL2, except at the early vitellogenic stage in the ovary. The expression of FOXL2, Cyp19a1a and Cyp19a1b was mainly localized in granulosa cells of ovaries. In S. argus testes, strong expression of FOXL2 gene was observed in the interstitial cells including tubules and Leydig cells, while Cyp19a1a and Cyp19a1b were mainly expressed in Sertoli cells throughout gametogenesis. These results show that FOXL2 plays an essential role in sexual development, and imply that it may regulate Cyp19a1a and Cyp19a1b expression in S. argus.