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.

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.

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