We discovered that the hox gene Abdominal B is specifically expressed in the secondary cells of the Drosophila male accessory gland. Using an Abd-B BAC reporter coupled with a collection of genetic deletions, we discovered an enhancer in the iab-6 regulatory domain that is responsible for Abd-B expression in these cells removal of which results in visible morphological defects in the secondary cells. Mates of iab-6 mutant males show defects in long-term egg laying and suppression of receptivity phenotypes. These data for the first time uncovered part of the function of the secondary cells. Transcriptome analysis from WT and mutant accessory glands led us to consider a list of 73 target genes that are down regulated in the mutant gland. The results RNAi experiments on these genes are presented in detail within the thesis. Interesting case of transvection as well as Gal4 toxicity are also included in these thesis.