Cargando…

Orbit/CLASP Is Required for Germline Cyst Formation through Its Developmental Control of Fusomes and Ring Canals in Drosophila Males

Orbit, a Drosophila ortholog of microtubule plus-end enriched protein CLASP, plays an important role in many developmental processes involved in microtubule dynamics. Previous studies have shown that Orbit is required for asymmetric stem cell division and cystocyte divisions in germline cysts and fo...

Descripción completa

Detalles Bibliográficos
Autores principales: Miyauchi, Chie, Kitazawa, Daishi, Ando, Itaru, Hayashi, Daisuke, Inoue, Yoshihiro H.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Public Library of Science 2013
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3592921/
https://www.ncbi.nlm.nih.gov/pubmed/23520495
http://dx.doi.org/10.1371/journal.pone.0058220
_version_ 1782262209161723904
author Miyauchi, Chie
Kitazawa, Daishi
Ando, Itaru
Hayashi, Daisuke
Inoue, Yoshihiro H.
author_facet Miyauchi, Chie
Kitazawa, Daishi
Ando, Itaru
Hayashi, Daisuke
Inoue, Yoshihiro H.
author_sort Miyauchi, Chie
collection PubMed
description Orbit, a Drosophila ortholog of microtubule plus-end enriched protein CLASP, plays an important role in many developmental processes involved in microtubule dynamics. Previous studies have shown that Orbit is required for asymmetric stem cell division and cystocyte divisions in germline cysts and for the development of microtubule networks that interconnect oocyte and nurse cells during oogenesis. Here, we examined the cellular localization of Orbit and its role in cyst formation during spermatogenesis. In male germline stem cells, distinct localization of Orbit was first observed on the spectrosome, which is a spherical precursor of the germline-specific cytoskeleton known as the fusome. In dividing stem cells and spermatogonia, Orbit was localized around centrosomes and on kinetochores and spindle microtubules. After cytokinesis, Orbit remained localized on ring canals, which are cytoplasmic bridges between the cells. Thereafter, it was found along fusomes, extending through the ring canal toward all spermatogonia in a cyst. Fusome localization of Orbit was not affected by microtubule depolymerization. Instead, our fluorescence resonance energy transfer experiments suggested that Orbit is closely associated with F-actin, which is abundantly found in fusomes. Surprisingly, F-actin depolymerization influenced neither fusome organization nor Orbit localization on the germline-specific cytoskeleton. We revealed that two conserved regions of Orbit are required for fusome localization. Using orbit hypomorphic mutants, we showed that the protein is required for ring canal formation and for fusome elongation mediated by the interaction of newly generated fusome plugs with the pre-existing fusome. The orbit mutation also disrupted ring canal clustering, which is essential for folding of the spermatogonia after cytokinesis. Orbit accumulates around centrosomes at the onset of spermatogonial mitosis and is required for the capture of one of the duplicated centrosomes onto the fusome. Moreover, Orbit is involved in the proper orientation of spindles towards fusomes during synchronous mitosis of spermatogonial cysts.
format Online
Article
Text
id pubmed-3592921
institution National Center for Biotechnology Information
language English
publishDate 2013
publisher Public Library of Science
record_format MEDLINE/PubMed
spelling pubmed-35929212013-03-21 Orbit/CLASP Is Required for Germline Cyst Formation through Its Developmental Control of Fusomes and Ring Canals in Drosophila Males Miyauchi, Chie Kitazawa, Daishi Ando, Itaru Hayashi, Daisuke Inoue, Yoshihiro H. PLoS One Research Article Orbit, a Drosophila ortholog of microtubule plus-end enriched protein CLASP, plays an important role in many developmental processes involved in microtubule dynamics. Previous studies have shown that Orbit is required for asymmetric stem cell division and cystocyte divisions in germline cysts and for the development of microtubule networks that interconnect oocyte and nurse cells during oogenesis. Here, we examined the cellular localization of Orbit and its role in cyst formation during spermatogenesis. In male germline stem cells, distinct localization of Orbit was first observed on the spectrosome, which is a spherical precursor of the germline-specific cytoskeleton known as the fusome. In dividing stem cells and spermatogonia, Orbit was localized around centrosomes and on kinetochores and spindle microtubules. After cytokinesis, Orbit remained localized on ring canals, which are cytoplasmic bridges between the cells. Thereafter, it was found along fusomes, extending through the ring canal toward all spermatogonia in a cyst. Fusome localization of Orbit was not affected by microtubule depolymerization. Instead, our fluorescence resonance energy transfer experiments suggested that Orbit is closely associated with F-actin, which is abundantly found in fusomes. Surprisingly, F-actin depolymerization influenced neither fusome organization nor Orbit localization on the germline-specific cytoskeleton. We revealed that two conserved regions of Orbit are required for fusome localization. Using orbit hypomorphic mutants, we showed that the protein is required for ring canal formation and for fusome elongation mediated by the interaction of newly generated fusome plugs with the pre-existing fusome. The orbit mutation also disrupted ring canal clustering, which is essential for folding of the spermatogonia after cytokinesis. Orbit accumulates around centrosomes at the onset of spermatogonial mitosis and is required for the capture of one of the duplicated centrosomes onto the fusome. Moreover, Orbit is involved in the proper orientation of spindles towards fusomes during synchronous mitosis of spermatogonial cysts. Public Library of Science 2013-03-08 /pmc/articles/PMC3592921/ /pubmed/23520495 http://dx.doi.org/10.1371/journal.pone.0058220 Text en © 2013 Miyauchi et al http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly credited.
spellingShingle Research Article
Miyauchi, Chie
Kitazawa, Daishi
Ando, Itaru
Hayashi, Daisuke
Inoue, Yoshihiro H.
Orbit/CLASP Is Required for Germline Cyst Formation through Its Developmental Control of Fusomes and Ring Canals in Drosophila Males
title Orbit/CLASP Is Required for Germline Cyst Formation through Its Developmental Control of Fusomes and Ring Canals in Drosophila Males
title_full Orbit/CLASP Is Required for Germline Cyst Formation through Its Developmental Control of Fusomes and Ring Canals in Drosophila Males
title_fullStr Orbit/CLASP Is Required for Germline Cyst Formation through Its Developmental Control of Fusomes and Ring Canals in Drosophila Males
title_full_unstemmed Orbit/CLASP Is Required for Germline Cyst Formation through Its Developmental Control of Fusomes and Ring Canals in Drosophila Males
title_short Orbit/CLASP Is Required for Germline Cyst Formation through Its Developmental Control of Fusomes and Ring Canals in Drosophila Males
title_sort orbit/clasp is required for germline cyst formation through its developmental control of fusomes and ring canals in drosophila males
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3592921/
https://www.ncbi.nlm.nih.gov/pubmed/23520495
http://dx.doi.org/10.1371/journal.pone.0058220
work_keys_str_mv AT miyauchichie orbitclaspisrequiredforgermlinecystformationthroughitsdevelopmentalcontroloffusomesandringcanalsindrosophilamales
AT kitazawadaishi orbitclaspisrequiredforgermlinecystformationthroughitsdevelopmentalcontroloffusomesandringcanalsindrosophilamales
AT andoitaru orbitclaspisrequiredforgermlinecystformationthroughitsdevelopmentalcontroloffusomesandringcanalsindrosophilamales
AT hayashidaisuke orbitclaspisrequiredforgermlinecystformationthroughitsdevelopmentalcontroloffusomesandringcanalsindrosophilamales
AT inoueyoshihiroh orbitclaspisrequiredforgermlinecystformationthroughitsdevelopmentalcontroloffusomesandringcanalsindrosophilamales