View Program - 63rd Annual Drosophila Research Conference

Wolbachia pipientis are maternally transmitted endosymbiotic bacteria commonly found in arthropods and nematodes. W. pipientis have complex interactions with their hosts, and many of these interactions serve to increase transmission. W. pipientis commonly manipulate reproduction of the host via cytoplasmic incompatibility, resulting in embryonic mortality. However, there are other known interactions between W. pipientis and its host. For example, W. pipientis rescues the bag of marbles (bam) partial loss of function (hypomorph) fertility phenotype in female Drosophila melanogaster. Bam is an important germline stem cell (GSC) gene involved in GSC renewal and cystoblast differentiation. GSCs are required for the production of egg and sperm, making the genetic interaction between W. pipientis and GSC genes such as bam of great evolutionary interest to us. While we understand that W. pipientis contributes to the rescue of the bam hypomorph phenotype, we have yet to determine the functional mechanisms that are behind this interaction. Therefore, we aim to elucidate 1) whether variation in W. pipientis variant genotype and titer influence the rescue of the mutant bam phenotype at different ages in adult females and 2) whether W. pipientis variants cause differential rescue of the bam hypomorph phenotype at the transcriptional level as the host fly ages. Results show that rescue of the mutant bam phenotype does in fact depend on the genotype of W. pipientis as the flies age and the magnitude of rescue is dependent on the age of the female fly. Relative quantification of W. pipientis titer via qPCR shows that titer increases in all W. pipientis genotypes at the peak rescue of the bam hypomorph phenotype. Our RNA-seq analysis revealed that W. pipientis infected Drosophila differentially express many of bam’s genetic and physical interactors in the bam hypomorph genotype. Additionally, pairwise comparisons between W. pipientis genotypes showed differential expression of one of bam’s genetic interactors, zpg, and several other GSC genes. RNAi will be used to determine whether any of these candidate genes identified from our RNA-seq analysis are responsible for aiding in the rescue of the bam hypomorph phenotype at the transcriptional level.

Assessing the interactions between W. pipientis genotype and titer on the bag of marbles partial loss of function mutant (hypomorph) in Drosophila melanogaster