Project Summary
Organelles engage in homeostatic processes to improve cellular health. However, some organelle proteins in
the soma can survive many months, making them susceptible to damage during aging. In the germline, gametes
can be arrested for a prolonged period before they pass down their organelle content to the next generation.
Having damage-prone proteins perdure in the germline would therefore be problematic and challenge the ability
of germ cells to pass down healthy material from generation to generation. Upon oocyte maturation and
fertilization, certain maternal products are degraded to initiate the maternal to zygotic transition in the developing
embryo, though little is known how maternally derived organelles are turned over and replaced with zygotic
organelles. Intriguingly, quality control events have been shown to take place in single cell organisms and during
asymmetric divisions to ensure the elimination of organelle long-lived proteins (LLPs). However, whether
specialized organelle quality control takes places to remove maternally derived LLPs in developing progeny, and
how such a process would take place in a multi-cellular organism remains poorly understood. Through molecular
and genetic analysis, the research proposed in this fellowship will investigate how maternal organelle input
derived from Drosophila oocytes influences germline health of their offspring. First, I will endogenously tag well
characterized LLPs to visualize the zygotic pool of proteins along with the maternally derived long-lived pool of
the same protein across embryonic, larval and adult progeny. By differentially tagging the maternal and zygotic
pool, I will compare protein levels in the progeny germline to assess if it selectively prevents maternally deposited
organelle LLPs to be transgenerationally inherited. Next, I will perturb oocyte health to investigate how maternally
damaged LLPs contributes to offspring viability. Finally, I will identify additional long-lived proteins that are
derived from maternal organelles using a biorthogonal amino acid labeling approach and compare their fates in
the progeny germline with well characterized LLPs. The proposed experiments will highlight how maternally
derived LLPs impact organelle function in the germline of ensuing progeny. In addition, these studies will shed
light on how organelle continuity is maintained between generations and aim to reveal specialized quality control
pathways in the germline.