Hong Kong University of Science and Technology, Hong Kong
Abstract: Germline cell development is a critical biological process that facilitates the generation of healthy gametes necessary for species reproduction. This process encompasses the self-renewal of germline stem cells (GSCs) and the differentiation of cysts. A comprehensive understanding of the intrinsic and extrinsic factors governing germline cell development is essential for elucidating mechanisms of stem cell maintenance and differentiation in adult tissues, and it may provide insights for advancements in regenerative medicine. RNA-binding protein 9 (Rbp9), a highly conserved member of the Elav/Hu family, has been previously implicated in promoting cystocyte differentiation in the Drosophila ovary. However, the molecular mechanisms underlying its function remain largely unexplored. In this study, we demonstrate that Rbp9 plays a pivotal role in regulating early GSC differentiation by directly binding to the 3’ untranslated region of key differentiation factors, including bam, sxl, mei-P26, and modulating their translation. Furthermore, our findings reveal that Rbp9 interacts directly with pAbp and eIF4E1, suggesting its potential role as a translational regulator. Collectively, our data indicate that Rbp9 regulates early germline cell differentiation in Drosophila through the translational regulation of its mRNA targets, rather than influencing mRNA stability as a post-transcriptional regulator.
Funding Source: This work was funded by the Hong Kong Research Grants Council (RGC) Theme-based Research Scheme grant, T13-602/21N.
