Date of this Version
Bakunina,Violetta (2023).The Effects of Temperature and Mito-Nuclear Interaction on Male Fertility in Drosophila. Undergraduate Honors Thesis. University of Nebraska-Lincoln.
The (simw501);Ore genotype is a strain of Drosophila melanogaster that has impaired mitochondrial function as a result of a disrupted interaction between a mitochondrially-encoded tRNATyr and the nuclear-encoded synthetase that aminoacylates mt-tRNATyr. We hypothesized that disruption of mitochondrial protein synthesis and oxidative phosphorylation (OXPHOS) in this genotype decreases mitochondrial translation and results in the sterility of (simw501);OreR males at 28oC. The results of Mitotracker staining showcased the reduced Mean Fluorescence Intensity (MFI), which confirms that sterility has an energetic basis, yet also that mature sperm function is compromised. Cytological dissection of male gonads revealed consistent morphological differences between (simw501);OreR and control genotypes, such as reduced seminal vesicle area, expanded sperm individualization testis site and failure of sperm to undergo proper individualization. Energetic deficiencies in mature sperm, along with physiological abnormalities during spermatogenesis, represent that (simw501);OreR does not meet the demands of the energy-costly process of spermatogenesis and thus fails to produce viable gamete. These factors together may be the underlying reason for male infertility of (simw501);OreR genotype. The incompatible (simw501);OreR genotype serves as a model for deciphering how mitochondrial dysfunction contributes to human disease and considering the benefits and costs of mitochondrial replacement therapy and novel treatments.