# SR Protein Kinase is expressed in Drosophila ovarian germline stem cells but is not essential for their self-renewal

## TL;DR

This study shows that SRPK is present in Drosophila germline stem cells but not required for their self-renewal.

## Contribution

The study reveals that SRPK is not essential for GSC self-renewal, suggesting functional redundancy with other kinases.

## Key findings

- SRPK is expressed in Drosophila germline stem cells and their dividing daughters.
- SRPK is not necessary for germline stem cell establishment or maintenance.
- Other protein kinases may compensate for the absence of SRPK.

## Abstract

Germline stem cells (GSCs) are necessary for oocyte production in
Drosophila
. GSC maintenance is regulated by intrinsic factors that promote their self-renewal. One such factor, the beta-importin,
Transportin-Serine/Arginine rich
, mediates nuclear import of serine/arginine-rich (SR) proteins, which are phosphorylated by SR protein kinases. Here, we investigate whether the kinase encoded by
SR protein kinase
(
SRPK
) is essential for GSC self-renewal. We find that SRPK is expressed in GSCs and their mitotically-dividing daughters, but is not necessary for GSC establishment or maintenance. We conclude that SRPK is dispensable for GSC self-renewal, and postulate that other protein kinases can compensate for its absence.