Sexually dimorphic neurons, which are distinct in males and females, control unique behaviors and are essential to reproductive success in most animals, including humans. Learning how sex-determining genes work with regulators of cell identity, division, and patterning to generate unique neurons in each sex is critical for understanding normal development, and may also provide clues about developmental disorders with higher incidence in one sex, such as autism. As a result, the relatively simple neuronal development of the nematode C. elegans has become an essential model for understanding sex-specific neuron specialization.
Using C. elegans as a tool for gene discovery, the goal of the proposed work is to investigate how sexually dimorphic neurons that control mating arise during embryonic development. A pilot genetic screen for msd (male-specific division defective) mutants, which fail to generate male-specific motor neurons, identified two mutations, ccc1 and ccc3. Additional msd mutations will be sought in a continued genetic screen. The genes affected by these msd mutations will be identified and their role in promoting sex-specific neuronal division will be explored using molecular genetic techniques and fluorescent markers of neuronal fate.
This project will provide Carleton College undergraduates and high school students participating in Carleton's Summer Science Institute hands-on experience with lab techniques and data presentation that will help them to succeed in their classes and empower them to seek out further engagement with scientific research. Students involved in the project will make significant, original research contributions to the field of neurobiology by discovering and studying new genes that mediate the development of neurons that regulate reproduction. As genes that control fundamental processes are often similar among diverse organisms, these studies may provide a basis for future investigations that shed light on human reproduction and on nervous system diseases that exhibit higher incidence in one sex.
