meiotic telomere clustering

Definition

Target type: biologicalprocess

The cell cycle process in which the dynamic reorganization of telomeres occurs in early meiotic prophase, during which meiotic chromosome ends are gathered in a bouquet arrangement at the inner surface of the nuclear envelope proximal to the spindle pole body. This plays an important role in progression through meiosis and precedes synapsis. [GOC:vw, PMID:10690419]

Meiotic telomere clustering is a crucial process that occurs during the prophase I stage of meiosis, specifically during the zygotene and pachytene substages. This process ensures proper homologous chromosome pairing and synapsis, which is essential for accurate segregation of chromosomes during meiosis I.

During zygotene, telomeres, the specialized structures at the ends of chromosomes, begin to associate with the nuclear envelope. This association is mediated by specific proteins, including the telomere-binding protein TRF2 and the nuclear envelope protein SUN1. As chromosomes continue to condense, telomeres from different chromosomes move closer together, ultimately forming a cluster at the nuclear periphery. This clustering is facilitated by the formation of a specialized structure called the telomere bouquet.

The telomere bouquet is a dynamic structure that constantly rearranges, allowing telomeres to explore the nuclear space and search for their homologous counterparts. As the telomere bouquet forms, chromosomes become progressively more organized, with sister chromatids tightly associated. This organization allows for the precise pairing of homologous chromosomes, which is a prerequisite for synapsis.

Synapsis is the process by which homologous chromosomes align along their entire length, forming a structure called the synaptonemal complex (SC). The SC is a proteinaceous structure that serves as a scaffold for the precise pairing and recombination of homologous chromosomes. Telomere clustering is essential for the efficient formation of the SC. It ensures that all telomeres are brought into close proximity, increasing the likelihood that homologous chromosomes will encounter each other and initiate synapsis.

Once synapsis is complete, telomere clustering gradually dissipates. This suggests that telomere clustering is a transient process that is specifically required for the initial stages of meiotic chromosome pairing and synapsis. Disruption of telomere clustering can lead to improper chromosome pairing, which can result in aneuploidy (an abnormal number of chromosomes) and other meiotic defects.

In summary, meiotic telomere clustering is a tightly regulated process that involves the coordinated action of multiple proteins. It plays a crucial role in the accurate pairing and synapsis of homologous chromosomes during prophase I of meiosis. Proper telomere clustering is essential for ensuring the faithful segregation of chromosomes during meiosis I, contributing to the genetic stability of offspring.'
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Proteins (1)

Compounds (20)