Discipline: Biological Sciences
Room: Marriott Balcony A
Jira T. White - Claflin University
Co-Author(s): Georgia Rapti,PhD, Rockefeller University, New York, NY; Shai Shaham, PhD, Rockefeller University, New York, NY
Studying how neural circuits develop is challenging because many key steps of these processes occur in utero. C. elegans, a small non-parasitic nematode, is ideal to observe these processes in vivo and dissect its key molecular events. It features a fully sequenced genome, conserved genes, cells, and processes with functional counterparts similar in humans. The C. elegans nervous system comprises of 302 neurons and 56 glial cells. Its brain-like neural circuit is called the Nerve Ring (NR) which forms a circle of ~180 axons surrounding the pharynx and associates with glia similar to mammalian astroglia. In different organisms, brain assembly is thought to begin with “pioneer axons” extending over non-neural cells, yet its underlying mechanisms are not clearly understood. Studies in the Shaham lab have demonstrated that in C. elegans, glia are essential in the initiation of brain circuit formation. A Chimaerin – Furin double mutant identified in that study presented a massive disruption of NR axon guidance. Studying this mutant and other conserved genes suggest that identifying pathways of circuit formation is difficult in part due to gene redundancies, where single mutants cannot reveal the roles of specific genes in circuit formation. As a continuation of the previously mentioned study, a series of double mutant strains were created with selected genes affecting certain signaling pathways or the extracellular matrix. At the end of this study, more than 30 new C. elegans strains were created and found to serve as appropriate tools to uncover the redundant roles of new genes in NR formation. They also allow the opportunity to observe the morphological structures of other nerve ring components for newly identified genes found in recent genetic screens. This investigation outlines how these strains can help further understand the role that glial cells play in the development of neural circuits.
Funder Acknowledgement(s): n/a
Faculty Advisor: Dr. Derrick Swinton, firstname.lastname@example.org
Role: This summer I created double mutant C. elegans strains that contained two different mutant genes. The first gene was identified in a previous study, and the second were candidate mutant genes that could interact with the previous. Doing so allowed us to determine rather or not the candidate mutant plays a role in glial mediated circuit formation. These strains also contained florescent markers for different elements of the C. elegans neuropil, primarily the AIY follower neuron, glial cells, and motoneurons so that the worms could be screened for defects. At the end of the summer, I created 36 different C. elegans strains and used them as a tool to uncover genetic interactions in the formation of the C. elegans neuropil.