RNAi in B. tryoni with transformer and transformer-2. (a) Diagramatic representation of dsRNA used to inject B. tryoni early embryos. Four different dsRNA fragments were designed to cover either overlapping thirds or the entire transcript of both female-specific tra and non-sex specific tra-2. (b) Preliminary results for injections of dsRNA fragments of both tra and tra-2 into either 3 hour or 7 hour embryos of B. tryoni. (c) Results of crosses between transformed males and wildtype females. In two cases (1) all progeny that resulted were female. In other cases (2) normal 1:1 male:female ratios were observed.