meiotic spindle midzone

Definition

Target type: cellularcomponent

The area in the center of the meiotic spindle where the spindle microtubules from opposite poles overlap. [GOC:kmv, PMID:12707312]

The meiotic spindle midzone is a specialized structure that forms between separating chromosomes during meiotic cell division. It is a dynamic and transient structure, crucial for the proper segregation of chromosomes and the subsequent cytokinesis.

Here's a detailed description of its cellular components:

**1. Microtubule Bundles:** The core of the midzone is formed by antiparallel bundles of microtubules from the two separating spindle poles. These microtubules are stabilized by various microtubule-associated proteins (MAPs), including:
* **MAP215/TOGp:** This protein acts as a microtubule-bundling factor, promoting the formation of the antiparallel microtubule bundles.
* **EB1:** This protein tracks the growing ends of microtubules and facilitates their interaction.
* **CLIP170:** This protein stabilizes microtubules and contributes to their bundling.

**2. Microtubule-Associated Proteins (MAPs):** In addition to the core microtubule bundles, several other MAPs contribute to the formation and function of the midzone. These include:
* **CENP-F:** This protein plays a role in linking the midzone to the chromosomes and is involved in the formation of the central spindle.
* **Kinesin-14:** This motor protein transports proteins along microtubules and helps to organize the midzone.
* **MCAK:** This kinesin-related protein acts as a depolymerase, regulating microtubule length and ensuring proper midzone formation.
* **CYK-4:** This protein is involved in the recruitment of contractile ring components and promotes cytokinesis.

**3. Central Spindle:** The midzone is also associated with the formation of the central spindle, which is a microtubule-based structure located in the middle of the dividing cell. The central spindle provides a platform for the recruitment of proteins involved in cytokinesis, including:
* **Myosin II:** This motor protein plays a crucial role in generating the contractile force required for cytokinesis.
* **Rho GTPase:** This signaling molecule regulates actin polymerization and the assembly of the contractile ring.

**4. Other Proteins:** The meiotic spindle midzone also contains various other proteins involved in signaling, membrane trafficking, and the regulation of cell cycle progression.

The precise composition of the midzone can vary depending on the species and cell type. However, the general principles of its structure and function are conserved across different organisms.
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Proteins (1)

Compounds (7)