The role of estrogen in gonadal sex differentiation in protandrous anemonefish Amphiprion clarkii ~Immunohistochemical localization of P450scc in gonads of male and female phases~
To obtain basic information on the mechanism of endocrine control of sex change, we examined the sexual differences in the expression of the steroidogenic enzyme, cytochrome P450 cholesterol side-chain cleavage enzyme (P450scc), in the gonads of the protandrous anemonefish. In the ambisexual gonad of fish in the male phase, strongly P450scc immunopositive cells were localized to cellular interstices both in mature testicular and in immature ovarian tissues. In the mature ovary of fish in the female phase, immunopositive cells were observed in the interstitial tissue among oocytes and in the thecal layer enclosing developed oocytes. These observations suggest that the ambisexual gonad of male phase has the ability to produce androgen in both the testicular and ovarian tissue.