Medfly early embryonic sexed transcriptomes: in silico approaches to identify sex-biased/male determining genes.

In C. capitata sex determination is controlled by a Y-linked male determining factor (M-factor) which influences, either directly or indirectly, the state of activity of the female determining master gene Cctraep (Cctra epigenetic) at 8-10 hours after egg laying. We have developed a Medfly transgenic sexing strain which produces male-only progeny (95% efficiency) by transgene-mediated RNAi against the female determiner Cctraep gene. C. capitata XX males are fully fertile and could be successfully mated with XX females thus leading to the production of female-only (XX) progeny. Starting from two polyA+ RNA preparations, extracted from XX-only and XYXX medfly embryos at 8-10 hours from oviposition, we have defined two de novo transcriptome sets consisting respectively of 42614 (XYXX, N50=2158) and 39255 (XX, N50=2047) assembled transcripts. In this talk we will outline the assembly testing pipeline, developed with a combination of different on-line and stand alone tools, and preliminary data on the in silico subtraction approach for the identification of male-biased genes/male-determining genes.