Here’s a really cool paper:

DNA Methylation of the Gonadal Aromatase (cyp19a) Promoter Is Involved in Temperature-Dependent Sex Ratio Shifts in the European Sea Bass

They show that temperature-dependent sex determination (or rather, in this case, trans-differentiation) is mediated by the methylation of the aromatase promoter.  An obvious question is whether the environmentally driven methylation of the promoters of genes involved in sexual differentiation could be a general mechanism in species with environmental sex determination.  I am sure lots of people will be asking this soon, at least in vertebrates.

Does anyone known a dipteran with temperature-dependent sex determination?  Can’t think of one right now.