Dissertations and Theses
Date of Award
2026
Document Type
Thesis
Department
Biology
First Advisor
Shubha Govind
Second Advisor
Amy Berkov
Third Advisor
Marta Kalamarz
Keywords
Drosophila, Inflammation, Immune signaling, Larval development, Prostaglandins, Tumors
Abstract
Cyclooxygenase enzymes play important functions in reproduction, immunity, and a variety of other processes. Previous genetic studies have revealed the conserved nature of cyclooxygenase-1 activity in Drosophila oogenesis. The fly gene peroxinectin (pxt), linked to prostaglandin production, is orthologous to mouse cyclooxygenase-1, and is essential for female fertility. We investigated pxt functions during post-embryonic development and show that loss-of function pxt mutants are semi-lethal, suggesting zygotic contributions of the pxt gene. We then show that RNA interference-mediated knock-down of pxt in the larval immune organs is also semi-lethal, larvae exhibit growth defects, and that this phenotype is diet-dependent. The fat body cells of knock-down animals are smaller than in control larvae without the knock-down, and these larvae develop melanotic tumors. Reducing the wild type dose of pxt enhances lethality, tumor penetrance, and tumor burden caused by a dominant hopscotch mutation that results in a constitutively active Janus kinase enzyme. Together these results imply that pxt plays a critical function in fly metabolism, and surprisingly, acts as a tumor suppressor in the hematopoietic system, likely contributing to the immune resolution. This interpretation supports a role for prostaglandins and lipid-mediated signaling in regulating the immune/metabolism axis in flies. They also point to new directions for future research.
Recommended Citation
Frydrych, Ewelina, "An immune-metabolic role for the Drosophila Cox-1 ortholog, Peroxinectin" (2026). CUNY Academic Works.
https://academicworks.cuny.edu/cc_etds_theses/1333
