Micrograph showing condensed chromosomes in blue and the mitotic spindle in green during prometaphase of mitosis

The mitotic spindle (a.k.a. the mitotic apparatus) is a structure of the eukaryotic cytoskeleton involved in mitosis and meiosis, often referred to as the meiotic spindle during meiosis. Its function is to segregate chromosomes during cell division (either mitosis or meiosis) to the daughter cells . It consists of a bundle of microtubules joined at the ends but spread out in the middle, vaguely ellipsoid in shape. In the wide middle portion, known as the spindle midzone, antiparallel microtubules are bundled by kinesins. At the pointed ends, known as spindle poles, microtubules are nucleated by the centrosomes. Image File history File links Download high-resolution version (778x621, 99 KB) Chromosomes (blue) and mitotic spindle (green) during cell division Source: Oak Ridge National Laboratory, Image Science and Machine Vision unit, http://www. ... Image File history File links Download high-resolution version (778x621, 99 KB) Chromosomes (blue) and mitotic spindle (green) during cell division Source: Oak Ridge National Laboratory, Image Science and Machine Vision unit, http://www. ... Figure 1: A representation of a condensed eukaryotic chromosome, as seen during cell division. ... Yeah. ... Mitosis divides genetic information during cell division. ... Kingdoms Animalia - Animals Fungi Plantae - Plants Protista A eukaryote (IPA: ) is an organism with a complex cell or cells, in which the genetic material is organized into a membrane-bound nucleus or nuclei. ... The eukaryotic cytoskeleton. ... Mitosis divides genetic information during cell division. ... Not to be confused with miosis. ... This does not cite its references or sources. ... In biology, a daughter cell is either one of the two cells that are formed when mitosis occurs in a cell. ... Microtubules are protein structures found within cells, one of the components of the cytoskeleton. ... 3D rendering of an ellipsoid In mathematics, an ellipsoid is a type of quadric that is a higher dimensional analogue of an ellipse. ... Kinesins typically consist of two large globular heads that allow attachment to microtubules, a central coiled region, and a region termed light-chain, which connects the kinesin to the intracellular component to be moved. ... The centrosome is the main microtubule organizing center (MTOC) of the cell as well as a regulator of cell-cycle progression. ...

During spindle assembly in mitosis, some of the spindle's microtubules attach to the kinetochores that assemble on the centromere portion of the chromosomes. The chromosomes are pulled into alignment along the spindle midzone to form the metaphase spindle. Once all the chromosomes are aligned with sister chromatids pointing to opposite ends of the spindle, the cell enters anaphase, in which the chromatids separate and move toward their respective poles. Since the center of the spindle specifies the plane along which the cell will divide during cytokinesis, this ensures that each daughter cell will receive one of each chromatid. Yeah. ... The kinetochore is the protein structure in eukaryotes which assembles on the centromere and links the chromosome to microtubule polymers from the mitotic spindle during mitosis. ... The centromere is a region of chromosomes with a special sequence and structure. ... Figure 1: A representation of a condensed eukaryotic chromosome, as seen during cell division. ... An image of a newt lung cell stained with flourescent dyes during metaphase. ... A chromatid forms one part of a chromosome after it has coalesced for the process of mitosis or meiosis. ... A lung cell of a newt during early anaphase of mitosis. ... A cell that has almost completed cytokinesis. ...

According to a recent publication^[1], Lamin B is a key component of the spindle matrix helping microtubule assembly, the mitotic spindle will not form without it. A lamin is a fibrous protein that gives the cell nucleus its shape. ...

References

1. ^ Tsai MY, Wang S, Heidinger JM, Shumaker DK, Adam SA, Goldman RD, Zheng Y. A mitotic lamin B matrix induced by RanGTP required for spindle assembly Science 2006 Mar 31;311(5769):1887-93. PMID 16543417

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