Limits...
Australin: a chromosomal passenger protein required specifically for Drosophila melanogaster male meiosis.

Gao S, Giansanti MG, Buttrick GJ, Ramasubramanyan S, Auton A, Gatti M, Wakefield JG - J. Cell Biol. (2008)

Bottom Line: Here we find that Drosophila melanogaster encodes two Borealin paralogues, Borealin-related (Borr) and Australin (Aust).We analyzed aust mutant spermatocytes to assess the effects of fully inactivating the Aust-dependent functions of the CPC.Our results indicate that Aust is required for sister chromatid cohesion, recruitment of the CPC to kinetochores, and chromosome alignment and segregation but not for meiotic histone phosphorylation or spindle formation.

View Article: PubMed Central - PubMed

Affiliation: Department of Zoology, University of Oxford, OX1 3PS Oxford, England, UK.

ABSTRACT
The chromosomal passenger complex (CPC), which is composed of conserved proteins aurora B, inner centromere protein (INCENP), survivin, and Borealin/DASRA, localizes to chromatin, kinetochores, microtubules, and the cell cortex in a cell cycle-dependent manner. The CPC is required for multiple aspects of cell division. Here we find that Drosophila melanogaster encodes two Borealin paralogues, Borealin-related (Borr) and Australin (Aust). Although Borr is a passenger in all mitotic tissues studied, it is specifically replaced by Aust for the two male meiotic divisions. We analyzed aust mutant spermatocytes to assess the effects of fully inactivating the Aust-dependent functions of the CPC. Our results indicate that Aust is required for sister chromatid cohesion, recruitment of the CPC to kinetochores, and chromosome alignment and segregation but not for meiotic histone phosphorylation or spindle formation. Furthermore, we show that the CPC is required earlier in cytokinesis than previously thought; cells lacking Aust do not initiate central spindle formation, accumulate anillin or actin at the cell equator, or undergo equatorial constriction.

Show MeSH

Related in: MedlinePlus

Aurora B and DmINCENP fail to localize at the kinetochores of aust spermatocytes. (A–C) Cells fixed and stained for DNA (blue), α-tubulin (green), and either CID (A), DmINCENP (B), or aurora B (C). In wild-type cells, all localize to kinetochores. In aust mutants, CID is present on kinetochores, whereas DmINCENP and aurora B are absent. Bar, 10 μm.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC2234246&req=5

fig6: Aurora B and DmINCENP fail to localize at the kinetochores of aust spermatocytes. (A–C) Cells fixed and stained for DNA (blue), α-tubulin (green), and either CID (A), DmINCENP (B), or aurora B (C). In wild-type cells, all localize to kinetochores. In aust mutants, CID is present on kinetochores, whereas DmINCENP and aurora B are absent. Bar, 10 μm.

Mentions: To assess the normality of kinetochores, we initially stained both wild-type and aust testes with antibodies to the core kinetochore component CID/CENP-A (Blower and Karpen, 2001). We found that CID localized to kinetochores during metaphase in both wild-type and aust meioses (Fig. 6 A). However, although robust kinetochore staining was apparent for both aurora B and DmINCENP in wild-type meiosis, this staining was completely absent in aust mutant spermatocytes (Fig. 6, B and C). Thus, Aust function is required for the recruitment of other CPC components to the kinetochore during male meiosis.


Australin: a chromosomal passenger protein required specifically for Drosophila melanogaster male meiosis.

Gao S, Giansanti MG, Buttrick GJ, Ramasubramanyan S, Auton A, Gatti M, Wakefield JG - J. Cell Biol. (2008)

Aurora B and DmINCENP fail to localize at the kinetochores of aust spermatocytes. (A–C) Cells fixed and stained for DNA (blue), α-tubulin (green), and either CID (A), DmINCENP (B), or aurora B (C). In wild-type cells, all localize to kinetochores. In aust mutants, CID is present on kinetochores, whereas DmINCENP and aurora B are absent. Bar, 10 μm.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2234246&req=5

fig6: Aurora B and DmINCENP fail to localize at the kinetochores of aust spermatocytes. (A–C) Cells fixed and stained for DNA (blue), α-tubulin (green), and either CID (A), DmINCENP (B), or aurora B (C). In wild-type cells, all localize to kinetochores. In aust mutants, CID is present on kinetochores, whereas DmINCENP and aurora B are absent. Bar, 10 μm.
Mentions: To assess the normality of kinetochores, we initially stained both wild-type and aust testes with antibodies to the core kinetochore component CID/CENP-A (Blower and Karpen, 2001). We found that CID localized to kinetochores during metaphase in both wild-type and aust meioses (Fig. 6 A). However, although robust kinetochore staining was apparent for both aurora B and DmINCENP in wild-type meiosis, this staining was completely absent in aust mutant spermatocytes (Fig. 6, B and C). Thus, Aust function is required for the recruitment of other CPC components to the kinetochore during male meiosis.

Bottom Line: Here we find that Drosophila melanogaster encodes two Borealin paralogues, Borealin-related (Borr) and Australin (Aust).We analyzed aust mutant spermatocytes to assess the effects of fully inactivating the Aust-dependent functions of the CPC.Our results indicate that Aust is required for sister chromatid cohesion, recruitment of the CPC to kinetochores, and chromosome alignment and segregation but not for meiotic histone phosphorylation or spindle formation.

View Article: PubMed Central - PubMed

Affiliation: Department of Zoology, University of Oxford, OX1 3PS Oxford, England, UK.

ABSTRACT
The chromosomal passenger complex (CPC), which is composed of conserved proteins aurora B, inner centromere protein (INCENP), survivin, and Borealin/DASRA, localizes to chromatin, kinetochores, microtubules, and the cell cortex in a cell cycle-dependent manner. The CPC is required for multiple aspects of cell division. Here we find that Drosophila melanogaster encodes two Borealin paralogues, Borealin-related (Borr) and Australin (Aust). Although Borr is a passenger in all mitotic tissues studied, it is specifically replaced by Aust for the two male meiotic divisions. We analyzed aust mutant spermatocytes to assess the effects of fully inactivating the Aust-dependent functions of the CPC. Our results indicate that Aust is required for sister chromatid cohesion, recruitment of the CPC to kinetochores, and chromosome alignment and segregation but not for meiotic histone phosphorylation or spindle formation. Furthermore, we show that the CPC is required earlier in cytokinesis than previously thought; cells lacking Aust do not initiate central spindle formation, accumulate anillin or actin at the cell equator, or undergo equatorial constriction.

Show MeSH
Related in: MedlinePlus