Author ORCID Identifier
https://orcid.org/0000-0002-1915-7038
Date of Award
12-31-2025
Document Type
Open Access Dissertation
Degree Name
Doctor of Philosophy (PhD)
Department
Biology/Molecular, Cellular, and Organismal Biology
First Advisor
Labib Rouhana
Abstract
Infertility affects 186 million people worldwide. Understanding the molecular processes that support the development of germ cells provides insight into the underlying issues that can cause infertility. The hermaphroditic flatworm Schmidtea mediterranea is an ideal model for studying development of gametes, as specification, development, and maintenance of both male and female germlines occur post-embryonically and continuously throughout their life. Initially, my research served to characterize Tousled-like kinases (TLKs), which are conserved regulators of plant and animal development. Mammalian TLK orthologs are most-highly expressed in the testes, but the role of TLKs in spermatogenesis has remained elusive because of embryonic lethality. I show that one of two TLK paralogs in the planarian S. mediterranea, one which has enriched expression in testes, is required for sperm development. Detailed analyses using genetic markers for specific stages of spermatogenesis revealed that TLK1a is required for development and/or maintenance of male germline stem cells (GSCs), but not oogenesis or female GSCs. I then sought to identify genes required specifically for female GSCs. I performed an RNA-seq screen that provided candidate genes that may support maintenance and development of female GSCs. Distribution of expression analyses through whole-mount in situ hybridization revealed expression of several candidate genes in the ovaries. Additional candidate genes are expressed in the testes, as well as in somatic cells within and outside reproductive organs, opening research avenues to uncover pathways implicated in regulation of germline development.
Recommended Citation
Huynh, Roger, "Analysis of conserved genes required for germline development and differentiation in the flatworm Schmidtea mediterranea" (2025). Graduate Doctoral Dissertations. 1123.
https://scholarworks.umb.edu/doctoral_dissertations/1123
Comments
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