Spindle positioning and cell polarity

Hyman, Anthony A.; Stearns, Tim

doi:10.1016/0960-9822(92)90660-3

Cited by 16 publications

(7 citation statements)

References 14 publications

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“…The identity of this structure is not clear, but it may mark a cortical site which interacts with astral microtubules to determine the positioning of the first cleavage furrow. In both the nematode Caenorhabditis elegans and the yeast Saccharomyces cerevisiae, cortical sites have been identified which determine the positioning of centrosomes and thus the axis of cell division (reviewed in Hyman & Stearns, 1992). In S. ingentis, the centrosomes of the first mitotic spindle become aligned with the RPN.1103-staining cortical site, and during second mitosis the centrosomes in one blastomere reposition to again become aligned with it.…”

Section: Discussionmentioning

confidence: 99%

The late events of fertilisation in the penaeoidean shrimpSicyonia ingentis

Hertzler

Clark

1993

Zygote

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Antibodies to sea urchin P-tubulin and mammalian heavy neurofilaments were used to study the late events of fertilisation in the penaeoidean shrimp Sicyonia ingentis. The neurofilament antibody fortuitously stained centrosomes in eggs, as well as the subacrosomal region and acrosomal filament in sperm. The neurofilament antibody also stained a cortial site in eggs which was associated with the positioning of the mitotic spindle. During pronuclear migration, a large maternal microtubule aster formed in addition to the sperm aster. The activity of the maternal centrosome disappeared during syngamy, while the sperm centrosomes formed the poles of the first mitotic spindle. Colcemid treatment modulated the size of the mitotic spindle and blocked pronuclear migration.

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Section: Discussionmentioning

confidence: 99%

The late events of fertilisation in the penaeoidean shrimpSicyonia ingentis

Hertzler

Clark

1993

Zygote

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“…These appear to be single microtubules, often with their distal end close to the edge of the cell ( Kilmartin and Adams, 1984 ). The genetic evidence for involvement of cytoplasmic microtubules in spindle orientation, and their proximity to the cell cortex, led to a model in which the cytoplasmic microtubules interact with a cortical attachment site through which they exert force on the nucleus ( Snyder et al, 1991 ; Hyman and Stearns, 1992 ), similar to what is observed for spindle rotation in C. elegans embryos ( Hyman, 1989 ).…”

mentioning

confidence: 92%

Microtubules Orient the Mitotic Spindle in Yeast through Dynein-dependent Interactions with the Cell Cortex

Carminati

Stearns

1997

The Journal of Cell Biology

455

404

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Proper orientation of the mitotic spindle is critical for successful cell division in budding yeast. To investigate the mechanism of spindle orientation, we used a green fluorescent protein (GFP)–tubulin fusion protein to observe microtubules in living yeast cells. GFP–tubulin is incorporated into microtubules, allowing visualization of both cytoplasmic and spindle microtubules, and does not interfere with normal microtubule function. Microtubules in yeast cells exhibit dynamic instability, although they grow and shrink more slowly than microtubules in animal cells. The dynamic properties of yeast microtubules are modulated during the cell cycle. The behavior of cytoplasmic microtubules revealed distinct interactions with the cell cortex that result in associated spindle movement and orientation. Dynein-mutant cells had defects in these cortical interactions, resulting in misoriented spindles. In addition, microtubule dynamics were altered in the absence of dynein. These results indicate that microtubules and dynein interact to produce dynamic cortical interactions, and that these interactions result in the force driving spindle orientation.

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“…The polarity of the dividing yeast cell is established first and then the spindle is aligned in response to this polarity to segregate the nuclei. This alignment is postulated to be mediated by interactions between cytoplasmic microtubules and asymmetrically localized cortical proteins ( Snyder et al, 1991 ; Hyman and Stearns, 1992 ). Spindle positioning in plant cells is similar to yeast in that the spindle appears to be aligned by preestablished cortical cues ( Staiger and Lloyd, 1991 ).…”

mentioning

confidence: 99%

Control of Mitotic Spindle Position by the Saccharomyces cerevisiae Formin Bni1p

Lee

Klee

Evangelista

et al. 1999

The Journal of Cell Biology

146

142

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Alignment of the mitotic spindle with the axis of cell division is an essential process in Saccharomyces cerevisiae that is mediated by interactions between cytoplasmic microtubules and the cell cortex. We found that a cortical protein, the yeast formin Bni1p, was required for spindle orientation. Two striking abnormalities were observed in bni1Δ cells. First, the initial movement of the spindle pole body (SPB) toward the emerging bud was defective. This phenotype is similar to that previously observed in cells lacking the kinesin Kip3p and, in fact, BNI1 and KIP3 were found to be in the same genetic pathway. Second, abnormal pulling interactions between microtubules and the cortex appeared to cause preanaphase spindles in bni1Δ cells to transit back and forth between the mother and the bud. We therefore propose that Bni1p may localize or alter the function of cortical microtubule-binding sites in the bud. Additionally, we present evidence that other bipolar bud site determinants together with cortical actin are also required for spindle orientation.

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Spindle positioning and cell polarity

Cited by 16 publications

References 14 publications

The late events of fertilisation in the penaeoidean shrimpSicyonia ingentis

The late events of fertilisation in the penaeoidean shrimpSicyonia ingentis

Microtubules Orient the Mitotic Spindle in Yeast through Dynein-dependent Interactions with the Cell Cortex

Control of Mitotic Spindle Position by the Saccharomyces cerevisiae Formin Bni1p

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