Cohesin

Cohesine are protein complexes that are in the cell, as well as during mitosis and meiosis crucial.

Cohesinmoleküle stabilize the chromatin in the cell and thus the three-dimensional structure of the chromosomes. During DNA replication in S- phase of the cell cycle by means of the two sister chromatids cohesin " rings " are bonded to each other throughout the length. At anaphase (mitosis ), an enzyme that separase Cohesine this dissolves again, and sister chromatids are pulled from the spindle fibers to the cell poles. In higher eukaryotes, the cohesin along the chromosome arms is already removed at the beginning of mitosis by phosphorylation by Polo - like kinase 1.

In meiosis, the sister chromatids Cohesine link next to the above, the homologous chromosomes during prophase I. Here Tetradenbildung in the separation of homologous chromosomes occurs during anaphase of the first meiotic division.