Function of the bxd ncRNA. Ana Borges, Welcome Bender. bcmp, harvard medical school, boston, MA.

   In Drosophila, the production of a ncRNA transcribed through the bxd regulatory region in the BX-C has been suggested as a mechanism for the regulation of Ubx expression. Using recombineering we were able to reconstruct a 45kb segment of the BX-C region bearing the bxd promoter/enhancer in a inverted fashion. This segment was patched back into a fly deleted for the same region though RMCE integration. Flies carrying the modified segment were analyzed for "in situ" RNA assays: no detection of bxd ncRNA was seen and a loss of the Ubx repression was noticeable in early development. However the flies did not show any homeotic phenotype. Our result suggests that the lack of transcription from the bxd promoter might have an affect on setting the state of the bxd PRE for the activation of Ubx.