Drosophila CG17003/leaky (lky) is required for microtubule acetylation in early germ cells in Drosophila ovary

Abstract

Microtubule acetylation is found in populations of stable, long-lived microtubules, occurring on the conserved lysine 40 (K40) residue of α-tubulin by α-tubulin acetyltransferases (αTATs). α-tubulin K40 acetylation has been shown to stabilize microtubules via enhancing microtubule resilience against mechanical stress. Here we show that a previously uncharacterized αTAT, Drosophila CG17003/leaky (lky), is required for α-tubulin K40 acetylation in early germ cells in Drosophila ovary. We found that loss of lky resulted in a progressive egg chamber fusion phenotype accompanied with mislocalization of germline-specific Vasa protein in somatic follicle cells. The same phenotype was observed upon replacement of endogenous α-tubulin84B with non-acetylatable α-tubulin84BK40A, suggesting α-tubulin K40 acetylation is responsible for the phenotype. Chemical disturbance of microtubules by Colcemid treatment resulted in a mislocalization of Vasa in follicle cells within a short period of time (~30 min), suggesting that the observed mislocalization is likely caused by direct leakage of cellular contents between germline and follicle cells. Taken together, this study provides a new function of α-tubulin acetylation in maintaining the cellular identity possibly by preventing the leakage of tissue-specific gene products between juxtaposing distinct cell types.

Homophilic interaction of E-Cadherin prevents cell-cell fusion between developing germline and surrounding epithelia inDrosophilaovary

“…FCs expressing germline determinants were thought to alter their cell fate and fail to properly specify FC subtypes [40]. Consistent with these reports, we found that shg RNAi and dCR4h ovaries exhibit fused egg chambers accompanied with ectopic expression of laminC, the marker of stalk cells, in main body FCs (Figure 4, Figure S2).…”

“…Previous reports have demonstrated that the misexpression or mislocalization of germline gene products in FCs results in cyst or egg-chamber individualization defect, where two or more germline cysts are surrounded by a single FC epithelium [39] [40].…”

“…Previous reports have demonstrated that the misexpression or mislocalization of germline gene products in FCs results in cyst or egg-chamber individualization defect, where two or more germline cysts are surrounded by a single FC epithelium [39] [40]. FCs expressing germline determinants were thought to alter their cell fate and fail to properly specify FC subtypes [40].…”

“…Previous reports have demonstrated that the misexpression or mislocalization of germline gene products in FCs results in cyst or egg-chamber individualization defect, where two or more germline cysts are surrounded by a single FC epithelium [39] [40]. FCs expressing germline determinants were thought to alter their cell fate and fail to properly specify FC subtypes [40]. Consistent with these reports, we found that shg RNAi and dCR4h ovaries exhibit fused egg chambers accompanied with ectopic expression of laminC, the marker of stalk cells, in main body FCs (Figure 4, Figure S2).…”