The sex cells, egg and sperm, are formed through a form of cellular division known as meiosis, resulting in four genetically unique daughter cells. During meiosis, accurate chromosome segregation is vital for reproductive success. Occasionally, chromosomal segregation errors occur, resulting in gametes with an incorrect number of chromosomes, a condition known as aneuploidy. Aneuploidy is known to be the leading cause of infertility in women. Aneuploids that survive cell division can cause spontaneous abortions or genetic disorders including Down’s Syndrome. Aneuploidy in women rapidly rises after the age of 35, a phenomenon known as the Maternal Age Effect. While several genes required for meiosis have been identified in Drosophila, most of these were identified in limited forward genetic screens or based on conservation in other organisms. Many meiotic genes remain to be identified, particularly those required for fertility or if they are poorly conserved. The goal of this project was to identify and characterize new meiotic genes in the Drosophila melanogaster genome. Using tissue expression patterns from the FlyAtlas and modENCODE databases, we identified 542 Drosophila genes of interest because their expression levels are elevated in meiotically active tissues. RNAi approaches were then used to make a germline targeted knockdown with the UAS/ Gal4 system to observe which of the genes of interest caused significant errors in meiosis (aneuploidy) or fertility. Out of the 265 genes we have tested so far, 67 were identified due to increased nondisjunction or sterility. We are currently prioritizing these genes and selecting a subset for further study.