Spermatogonia derived RpS13 non-autonomously regulates the cyst cell differentiation via Rho1-mediated adhesion junctions in Drosophila testis

ObjectiveIn the testis of Drosophila, spermatogonia transit-amplification (TA) divisions are necessary for germline proliferation and differentiation. Both the germline and the surrounding somatic cyst cells (SCCs) have a significant influence on these processes. However, the underlying mechanism is largely unknown. MethodsFlies were used to generate tissue-specific gene knockdown. Immunofluorescence was used to determine protein localization and expression pattern. Small interfering RNAs were used to knockdown genes in S2 cells. qRT-PCR was used to examine the relative mRNA expression level. ResultsOur findings indicate that spermatogonial RpS13 regulates cyst cell growth through a non-autonomous manner. In terms of mechanism, RpS13 may regulate the adhesion junctions of the soma-germline via the DE-cad and Arm proteins in addition to dpERK, which is found in SCCs. Interestingly, Rho1 and RpS13 mutually inhibit each other in Drosophila S2 cells. Additionally, Rho1 controlled cell adhesions that rely on DE-cad, Arm, and dpERK and imitated the actions of RpS13 in Drosophila testis. ConclusionAll of these findings implied that during spermatogonia TA-divisions in the testis of Drosophila, RpS13 regulates the development of cyst cells via Rho1-mediated adhesion junctions.