Spindle assembly without spindle pole body insertion into the nuclear envelope in fission yeast meiosis

Chromosoma ◽  
2019 ◽  
Vol 128 (3) ◽  
pp. 267-277 ◽  
Author(s):  
Alberto Pineda-Santaella ◽  
Alfonso Fernández-Álvarez
Keyword(s):  
Nuclear Envelope ◽  
Fission Yeast ◽  
Spindle Pole Body ◽  
Spindle Assembly ◽  
Spindle Pole ◽  
Pole Body ◽  
Yeast Meiosis

scholarly journals A microtubule polymerase cooperates with the kinesin-6 motor and a microtubule cross-linker to promote bipolar spindle assembly in the absence of kinesin-5 and kinesin-14 in fission yeast

2017 ◽  
Vol 28 (25) ◽  
pp. 3647-3659 ◽  
Author(s):  
Masashi Yukawa ◽  
Tomoki Kawakami ◽  
Masaki Okazaki ◽  
Kazunori Kume ◽  
Ngang Heok Tang ◽  
...  
Keyword(s):  
Fission Yeast ◽  
Chromosome Segregation ◽  
Spindle Pole Body ◽  
Spindle Assembly ◽  
Spindle Pole ◽  
Temperature Sensitive ◽  
Bipolar Spindle ◽  
Pole Body ◽  
Cross Linker ◽  
Spindle Elongation

Accurate chromosome segregation relies on the bipolar mitotic spindle. In many eukaryotes, spindle formation is driven by the plus-end–directed motor kinesin-5 that generates outward force to establish spindle bipolarity. Its inhibition leads to the emergence of monopolar spindles with mitotic arrest. Intriguingly, simultaneous inactivation of the minus-end–directed motor kinesin-14 restores spindle bipolarity in many systems. Here we show that in fission yeast, three independent pathways contribute to spindle bipolarity in the absence of kinesin-5/Cut7 and kinesin-14/Pkl1. One is kinesin-6/Klp9 that engages with spindle elongation once short bipolar spindles assemble. Klp9 also ensures the medial positioning of anaphase spindles to prevent unequal chromosome segregation. Another is the Alp7/TACC-Alp14/TOG microtubule polymerase complex. Temperature-sensitive alp7cut7pkl1 mutants are arrested with either monopolar or very short spindles. Forced targeting of Alp14 to the spindle pole body is sufficient to render alp7cut7pkl1 triply deleted cells viable and promote spindle assembly, indicating that Alp14-mediated microtubule polymerization from the nuclear face of the spindle pole body could generate outward force in place of Cut7 during early mitosis. The third pathway involves the Ase1/PRC1 microtubule cross-linker that stabilizes antiparallel microtubules. Our study, therefore, unveils multifaceted interplay among kinesin-dependent and -independent pathways leading to mitotic bipolar spindle assembly.

scholarly journals Targeting Alp7/TACC to the spindle pole body is essential for mitotic spindle assembly in fission yeast

FEBS Letters ◽  
2014 ◽  
Vol 588 (17) ◽  
pp. 2814-2821 ◽  
Author(s):  
Ngang Heok Tang ◽  
Naoyuki Okada ◽  
Chii Shyang Fong ◽  
Kunio Arai ◽  
Masamitsu Sato ◽  
...  
Keyword(s):  
Fission Yeast ◽  
Mitotic Spindle ◽  
Spindle Pole Body ◽  
Spindle Assembly ◽  
Spindle Pole ◽  
Pole Body ◽  
Mitotic Spindle Assembly

scholarly journals Spindle pole body components are reorganized during fission yeast meiosis

2012 ◽  
Vol 23 (10) ◽  
pp. 1799-1811 ◽  
Author(s):  
Midori Ohta ◽  
Masamitsu Sato ◽  
Masayuki Yamamoto
Keyword(s):  
Fission Yeast ◽  
Meiotic Prophase ◽  
Spindle Pole Body ◽  
Mitotic Cell ◽  
Spindle Pole ◽  
Nuclear Movement ◽  
Pole Body ◽  
Proper Number ◽  
Body Components ◽  
Yeast Meiosis

During meiosis, the centrosome/spindle pole body (SPB) must be regulated in a manner distinct from that of mitosis to achieve a specialized cell division that will produce gametes. In this paper, we demonstrate that several SPB components are localized to SPBs in a meiosis-specific manner in the fission yeast Schizosaccharomyces pombe. SPB components, such as Cut12, Pcp1, and Spo15, which stay on the SPB during the mitotic cell cycle, disassociate from the SPB during meiotic prophase and then return to the SPB immediately before the onset of meiosis I. Interestingly, the polo kinase Plo1, which normally localizes to the SPB during mitosis, is excluded from them in meiotic prophase, when meiosis-specific, horse-tail nuclear movement occurs. We found that exclusion of Plo1 during this period was essential to properly remodel SPBs, because artificial targeting of Plo1 to SPBs resulted in an overduplication of SPBs. We also found that the centrin Cdc31 was required for meiotic SPB remodeling. Thus Plo1 and a centrin play central roles in the meiotic SPB remodeling, which is essential for generating the proper number of meiotic SPBs and, thereby provide unique characteristics to meiotic divisions.

scholarly journals Membrane proteins Bqt3 and -4 anchor telomeres to the nuclear envelope to ensure chromosomal bouquet formation

2009 ◽  
Vol 187 (3) ◽  
pp. 413-427 ◽  
Author(s):  
Yuji Chikashige ◽  
Miho Yamane ◽  
Kasumi Okamasa ◽  
Chihiro Tsutsumi ◽  
Tomoko Kojidani ◽  
...  
Keyword(s):  
Nuclear Envelope ◽  
Fission Yeast ◽  
Nuclear Membrane ◽  
Meiotic Prophase ◽  
Spindle Pole Body ◽  
Spindle Pole ◽  
Null Mutant ◽  
Vegetative Cells ◽  
Nuclear Membranes ◽  
Pole Body

In many organisms, telomeres cluster to form a bouquet arrangement of chromosomes during meiotic prophase. Previously, we reported that two meiotic proteins, Bqt1 and -2, are required for tethering telomeres to the spindle pole body (SPB) during meiotic prophase in fission yeast. This study has further identified two novel, ubiquitously expressed inner nuclear membrane (INM) proteins, Bqt3 and -4, which are required for bouquet formation. We found that in the absence of Bqt4, telomeres failed to associate with the nuclear membranes in vegetative cells and consequently failed to cluster to the SPB in meiotic prophase. In the absence of Bqt3, Bqt4 protein was degraded during meiosis, leading to a phenotype similar to that of the bqt4-null mutant. Collectively, these results show that Bqt4 anchors telomeres to the INM and that Bqt3 protects Bqt4 from protein degradation. Interestingly, the functional integrity of telomeres is maintained even when they are separated from the nuclear envelope in vegetative cells.

Pcp1/pericentrin controls the SPB number in fission yeast meiosis and ploidy homeostasis

2021 ◽  
Vol 221 (1) ◽  
Author(s):  
Qian Zhu ◽  
Zhaodi Jiang ◽  
Xiangwei He
Keyword(s):  
Cell Division ◽  
Sexual Reproduction ◽  
Schizosaccharomyces Pombe ◽  
Fission Yeast ◽  
Spindle Pole Body ◽  
Spindle Pole ◽  
Bipolar Spindle ◽  
Pole Body ◽  
Yeast Meiosis ◽  
Quantity Control

During sexual reproduction, the zygote must inherit exactly one centrosome (spindle pole body [SPB] in yeasts) from the gametes, which then duplicates and assembles a bipolar spindle that supports the subsequent cell division. Here, we show that in the fission yeast Schizosaccharomyces pombe, the fusion of SPBs from the gametes is blocked in polyploid zygotes. As a result, the polyploid zygotes cannot proliferate mitotically and frequently form supernumerary SPBs during subsequent meiosis, which leads to multipolar nuclear divisions and the generation of extra spores. The blockage of SPB fusion is caused by persistent SPB localization of Pcp1, which, in normal diploid zygotic meiosis, exhibits a dynamic association with the SPB. Artificially induced constitutive localization of Pcp1 on the SPB is sufficient to cause blockage of SPB fusion and formation of extra spores in diploids. Thus, Pcp1-dependent SPB quantity control is crucial for sexual reproduction and ploidy homeostasis in fission yeast.

scholarly journals Chromosomes Rein Back the Spindle Pole Body during Horsetail Movement in Fission Yeast Meiosis

2014 ◽  
Vol 39 (2) ◽  
pp. 93-100 ◽  
Author(s):  
Yuji Chikashige ◽  
Miho Yamane ◽  
Kasumi Okamasa ◽  
Chie Mori ◽  
Noriko Fukuta ◽  
...  
Keyword(s):  
Fission Yeast ◽  
Spindle Pole Body ◽  
Spindle Pole ◽  
Pole Body ◽  
Yeast Meiosis

Distinct nuclear and spindle pole body populations of cyclin–cdc2 in fission yeast

Nature ◽  
1990 ◽  
Vol 347 (6294) ◽  
pp. 680-682 ◽  
Author(s):  
Caroline E. Alfa ◽  
Bernard Ducommun ◽  
David Beach ◽  
Jeremy S. Hyams
Keyword(s):  
Fission Yeast ◽  
Spindle Pole Body ◽  
Spindle Pole ◽  
Pole Body

Fine structure of the haplosporidan Kernstab, a persistent, intranuclear mitotic apparatus

1975 ◽  
Vol 18 (2) ◽  
pp. 327-346
Author(s):  
F.O. Perkins
Keyword(s):  
Fine Structure ◽  
Nuclear Envelope ◽  
Light Microscope ◽  
Spindle Pole Body ◽  
Spindle Pole ◽  
Interphase Nuclei ◽  
Mitotic Apparatus ◽  
Pole Body

The fine structure of the haplosporidan mitotic apparatus is described from observations of plasmodial nuclei of Minchinia nelsoni, M. costalis, Minchinia sp., and Urosporidium crescens. The apparatus, which is the Kernstab of light-microscope studies, consists of a bundle of microtubules terminating in a spindle pole body (SPB) at each end of the bundle. A few microtubules extend from SPB to SPB, but most either extend from an SPB and terminate in the nucleoplasm or lie in the nucleoplasm, free of either SPB. The bundle lengthens during mitosis, increasing the SPB-to-SPB distance by a factor of 2 to 3 as compared to interphase nuclei. SPBs are not in contact with the nuclear envelope, being found always in the nucleoplasm which is delimited by the nuclear envelope throughout mitosis. The mitotic apparatus is persistent through interphase, at least in a form which is not significantly different from that found in mitotic nuclei.

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