Axial structures of the meiotic chromosomes formed by cohesin complexes Biology Diagrams Segregation of chromosomes in mitosis is preceded by chromosome reorganization into the characteristic mitotic shapes observed in most animal cells. This chromosome reorganization takes place during early mitosis (prophase and prometaphase) and involves two major structural changes. First, sister chromatids are resolved from each other while both sister chromatid cohesion and DNA catenation
The key difference between meiosis and mitosis is that meiotic cells undergo two cell divisions, meiosis I and meiosis II, without an intervening S phase. During meiosis I, the chromatin condenses as in mitosis and the sister chromatids are held together through a process called cohesion.
Roles of Cohesin and Condensin in Chromosome Dynamics During Mammalian ... Biology Diagrams
Abstract The faithful segregation of genetic information requires highly orchestrated changes of chromosome structure during the mitotic cell cycle. The linkage between duplicated sister DNAs is established during S phase and maintained throughout G2 phase (cohesion). In early mitosis, dramatic structural changes occur to produce metaphase chromosomes, each consisting of a pair of compacted While one of the primary roles for chromosome cohesion in bi-orientation and mitotic chromosome segregation is well-established, the complexities of the regulation of cohesion are still being discovered.
Cohesin is a ring-shaped protein complex that organises the genome, enabling its condensation, expression, repair and transmission. In this Primer, Makrantoni and Marston summarise the molecular functions and regulation of cohesin that underlie its central role in chromosome segregation during mitosis.
Condensin and cohesin: more than chromosome compactor and glue Biology Diagrams
In mitosis, cohesin maintains sister chromatid cohesion mainly at centromeres, while most cohesin is removed from chromosome arms until metaphase (meta). Condensins I and II are recruited to the chromatid axes and participate to construct mitotic chromosomes. Many of the proteins that regulate cohesin function during mitosis also appear to regulate cohesin during meiosis. Here we review how cohesin contributes to meiotic chromosome dynamics, and explore similarities and differences between cohesin regulation during the mitotic cell cycle and meiotic progression.
