667C Poster - 10. Cell biology: Cytoskeleton, organelles and trafficking
Saturday April 09, 1:30 PM - 3:30 PM

Authors:
Claire Olson; Caroline Phan; Tommy Mason; Kyle Kowalewski; Sam Kavarana; Vivienne Fang; Karen G Hales

Affiliation: Davidson College

Keywords:
h. mitochondria; a. spermatogenesis

Drosophila spermatogenesis involves significant morphological changes in mitochondria and thus provides a useful system to study genes that regulate mitochondrial movement and shaping. The Z2-3738 recessive male sterile fly strain, originating from the Zuker collection, displays defects in spermatogenesis, including male sterility and disorganized sperm bundles with scattered short mitochondrial aggregates, due to a nonsense mutation in CG5755, a testis-specific gene. Its paralog, CG8931, is expressed in most other tissues. The human ortholog, SLC25A46, a member of a mitochondrial solute carrier family, has been shown to localize to the mitochondrial outer membrane and function in mitochondrial fission. SLC25A46 has been implicated in several human neurodegenerative diseases; thus, elucidating the function of its Drosophila orthologs may provide valuable insight into these conditions. Here, we characterize the function of CG5755 by exploring its localization, interactions, and putative role in the nervous system as proposed by others. We observed localization of a CG5755-GFP transgenic protein in the mitochondria of sperm bundles and potentially in the nebenkern. We investigated genetic interactions of CG5755 with genes involved in mitochondrial morphology, including the fusion gene fzo and cristae shaping gene mic60, and observed a synthetic phenotype in combined Z2-3738 and fzo mutants, suggesting that CG5755 may function in a conserved mitochondrial fusion pathway with fzo. Additionally, although current RNA-seq data report CG5755 as a testis-specific gene, another group reported evidence of neurological defects in neuron-specific CG5755 knockdown flies. We conducted experiments to determine whether CG5755-GFP localizes to nervous system tissues and whether Z2-3738 flies show defects in locomotor function. Together, these results confirm the role of CG5755 in mitochondrial shaping in spermatogenesis, provide preliminary evidence about its function in mitochondrial dynamics and its interactions with other relevant genes, and demonstrate whether it is functionally active in the nervous system.