Fertility depends on the establishment and maintenance of interactions between germ cells and somatic cells within the gonad. During embryonic development, primordial germ cells (PGCs) and somatic gonadal precursor cells (SGPs) are specified at distal locations, and they must migrate, coalesce, and interact to form a gonad with the proper architecture. This work focuses on the characterization of the molecular mechanisms that regulate the migration of the SGPs, their interactions with each other, and their interactions with the PGCs during Drosophila gonadogenesis. A genetic screen resulted in the identification of a number of genes linked to the cytoskeleton genetically or molecularly that are required for gonad morphogenesis, including two transcription factors, ribbon (rib) and longitudinals lacking (lola). rib and lola encode members of the BTB (Broad complex, Tramtrack, Bric-à-Brac) family of proteins, and are required for the coalescence and compaction of SGPs and PGCs into a cohesive, spherical gonad. Both genes are expressed in the embryonic gonad, and genetic studies reveal that these genes may function in a common pathway to promote gonad morphogenesis. As BTB proteins form homo- and heteromeric complexes, we tested the ability of these proteins to interact via their BTB domains and observe both homo- and heterodimerization of the BTB domains of both proteins, suggesting that these proteins may cooperate to regulate a common set of target genes. Studies are underway to determine if these proteins function predominantly in transcriptional activation or repression and to identify the downstream targets through which they function. In addition, previous studies by Davies et al. 2013 demonstrated a requirement for Lola in the adult testis. Therefore, we examined a potential role for Rib in homeostasis in the adult gonad. We observe expression of Rib in the germ cells and somatic cells of the adult testis. Current studies are focused on identifying the role of Rib in these cell types in the adult testis. These studies suggest that Rib and Lola cooperate to regulate early gonad morphogenesis, and that Rib may function similarly to Lola to regulate homeostasis in the adult.