Date Available
8-1-2026
Year of Publication
2024
Degree Name
Doctor of Philosophy (PhD)
Document Type
Doctoral Dissertation
College
Arts and Sciences
Department/School/Program
Biology
First Advisor
Dr. Douglas Harrison
Abstract
The JAK/STAT pathway is renowned for its involvement in diverse cellular processes, yet its precise role in the later events of spermiogenesis needs to be clarified. Spermiogenesis unfolds in the testis, where synchronized spermatid development occurs within two somatic cyst cells before being released into the seminal vesicle. Prior to this release, spermatid bundles undergo individualization, where F-actin investment cones accumulate at the nuclei of elongated spermatids and move down the length of the interconnected cysts, stripping away excess organelles and cytoplasm, resulting in individual spermatids that are then coiled and released into the testis lumen. Individualization depends on JAK/STAT signaling in the somatic cyst cells, and while the morphological changes during individualization are well-documented, the underlying signaling molecules and mechanisms remain incompletely understood.
To address this gap and consider the reutilized role of the JAK/STAT pathway in Drosophila spermatogenesis, an RNA-Seq experiment was conducted to compare the transcription profile of fly testes in which the JAK/STAT pathway has been knocked down in cyst cells to those of wild-type animals. Subsequent RNAi experiments of the down-regulated genes in germline and somatic cyst cells revealed significant disruptions in sperm development and individualization. Knockdown of mmp and scrib that are known to affect similar soma-germline barriers result in loss of septate junctions, and a significant negative impact on individualization. Furthermore, the knockdown of JAK/STAT signaling in somatic cyst cells resulted in a significant loss of septate junctions. These findings suggest that the JAK/STAT pathway influences the mechanical stability of spermatid bundles during the morphological changes of individualization, providing insights into the intricate dynamics of Drosophila spermatogenesis and soma-germline relations.
Digital Object Identifier (DOI)
https://doi.org/10.13023/etd.2024.352
Recommended Citation
Dadkhah, Sepideh, "Elucidating the effect of JAK/STAT signaling on Initiation of individualization" (2024). Theses and Dissertations--Biology. 107.
https://uknowledge.uky.edu/biology_etds/107
