RRC ID 305
Author Máthé E, Inoue YH, Palframan W, Brown G, Glover DM.
Title Orbit/Mast, the CLASP orthologue of Drosophila, is required for asymmetric stem cell and cystocyte divisions and development of the polarised microtubule network that interconnects oocyte and nurse cells during oogenesis.
Journal Development
Abstract Drosophila oocyte differentiation is preceded by the formation of a polarised 16-cell cyst from a single progenitor stem cell as a result of four rounds of asymmetric mitosis followed by incomplete cytokinesis. We show that the Orbit/Mast microtubule-associated protein is required at several stages in the formation of such polarised 16-cell cysts. In wild-type cysts, the Orbit/Mast protein not only associates with the mitotic spindle and its poles, but also with the central spindle (spindle remnant), ring canal and fusome, suggesting it participates in interactions between these structures. In orbit mutants, the stem cells and their associated fusomes are eventually lost as Orbit/Mast protein is depleted. The mitotic spindles of those cystocytes that do divide are either diminutive or monopolar, and do not make contact with the fusome. Moreover, the spindle remnants and ring canals fail to differentiate correctly in such cells and the structure of fusome is compromised. The Orbit/Mast protein thus appears to facilitate multiple interactions of the fusome with mitotic spindles and ring canals. This ensures correct growth of the fusome into a branched asymmetrically distributed organelle that is pre-determinative of 16-cell cyst formation and oocyte fate specification. Finally the Orbit/Mast protein is required during mid-oogenesis for the organisation of the polarised microtubule network inside the 16-cell cyst that ensures oocyte differentiation. The localisation of CLIP-190 to such microtubules and to the fusome is dependent upon Orbit/Mast to which it is complexed.
Volume 130(5)
Pages 901-15
Published 2003-3-1
DOI 10.1242/dev.00315
PMID 12538517
MeSH Animals Cell Differentiation / physiology Cell Division / physiology* Cell Polarity* Chimera / physiology Contractile Proteins / metabolism Drosophila Proteins / genetics Drosophila Proteins / metabolism* Drosophila melanogaster / genetics Drosophila melanogaster / growth & development Drosophila melanogaster / physiology* Female Microtubule-Associated Proteins / genetics Microtubule-Associated Proteins / metabolism* Microtubules / metabolism* Mutation Oocytes / cytology Oocytes / physiology* Oogenesis / physiology* Ovary / cytology Ovary / physiology Phenotype Spindle Apparatus / metabolism Stem Cells / physiology Tubulin / metabolism
IF 5.763
Times Cited 38