Functional Analysis of Chinmo, A Presumed Transcriptional Regulator of Cell Fate and Behavior in Drosophila.

Sex determination, the assignment of sex along a male or female fate, is essential for a species to retain sexual dimorphism and the ability to reproduce sexually. In many organisms, sex-specific transcriptional programs must also be maintained throughout an organism’s lifetime. For instance, if sex of stem cells is not continually reinforced, then entire organs could undergo a sex transformation (Zarkower, 2014). Chronologically inappropriate morphogenesis (Chinmo) is a putative transcription factor found in Drosophila that regulates cell fate and behavior. Specifically, it is essential for maintenance of male stem cell sex in the adult testis (Ma et al., 2014). Goals of this research were to investigate how Chinmo is regulated, and how Chinmo controls cell fate and behavior in Drosophila. We hypothesized that key domains and modifiers of Chinmo modulate its function. We found that Chinmo contains several putative SUMO (Small Ubiquitin-Like Modifier) interacting motifs and sumoylation consensus sites that may play a role in regulating its function. Using yeast two-hybrid assays we sought to identify proteins that physically interact with Chinmo, and investigate their functional relevance in the Drosophila testis using RNAi knockdown. This research elucidates the function of the Drosophila protein Chinmo and sheds light on how stem cell sex is properly regulated throughout an organism’s lifetime