Expression pattern of the <I>foxl2</I> gene in the scallop <I>Chlamys farreri</I> during development

Abstract

Foxl2 is a female related gene that plays a role in ovarian development and maintenance of function in mammals.However,little is know about the expression and function of foxl2 during early embryonic development. We investigated the pattern of foxl2(Cf-foxl2) expression during development in the scallop,Chlamys farreri, using qRT-PCR and in situ hybridization.The expression of Cf-foxl2 mRNA was low in the fertilized egg,but increased during development.The level of expression was highest in D-shaped larvae,after which levels declined significantly.In situ hybridization revealed that Cf-foxl2 mRNA was evenly distributed in the embryos up to the trochophore stage,at which point we observed a strong positive signal concentrated in the ventral surface near the concave region of the mouth.The intensity of the signal increased significantly in D-shaped larvae,was strongest in the dorsal part of the visceral mass and the margin of mantle,and was distributed symmetrically.Thereafter,the signal disappeared until sex differentiation,at which time the signal was only detected in the ovary.Our results suggest that the foxl2 gene participates in the regulation of ovarian development.Furthermore,given the persistent expression during the early development stages,we hypothesize that this gene plays a role in the development of C. farreri.