Cinetocoros

Cinetocoros, or kinetochores in English, are protein-rich structures located at the centromere region of chromosomes. In Spanish-language biology texts, cinetocoro is the singular form and cinetocoros is the plural. Kinetochores assemble on centromeric chromatin that contains the histone variant CENP-A and serve as the primary linkage between chromosomes and the mitotic spindle.

During mitosis and meiosis, cinetocoros mediate the attachment of spindle microtubules to chromosomes. The inner kinetochore binds centromeric chromatin, while the outer kinetochore interfaces with microtubules via the KMN network, which includes the KNL1 complex, the Mis12 complex, and the Ndc80 complex.

These attachments generate forces that move chromosomes toward opposite poles. The kinetochore also senses and responds to tension and microtubule dynamics, contributing to the spindle assembly checkpoint by recruiting proteins such as Mad and Bub family members to delay anaphase if attachments are incorrect.

Attachments are corrected through microtubule dynamics and regulatory kinases such as Aurora B; errors can lead to aneuploidy, a common feature in cancer.

Kinetochores are highly conserved across eukaryotes, though their composition varies; some organisms use additional factors such as the Dam1/DASH complex in yeast to form rings around microtubules.

Detection and study rely on immunofluorescence, live-cell imaging, and chromosome spreads.