减数分裂特异性黏连蛋白rec8功能域的分析，首发论文 -全讯担保网

analysis of the functional domains of the meiosis-specific cohesin subunit rec8

• 1、sxience cebter for future foods, jiangnan university, wuxi 214122
• 2、 school of biotechnology, jiangnan university, wuxi 214122

abstract：in mitosis, sister chromatid cohesion is established dependent on the cohesin complex in s phase and maintained until metaphase when the sister chromatids are captured by spindle microtubules from opposite poles (bi-orientation of kinetochores). for the onset of anaphase, the anaphase-promoting complex (apc) triggers the degradation of securin, an inhibitory chaperone for separase that cleaves the cohesin subunit rad21 and removes the cohesin complex along the entire chromosome. this removal of cohesin triggers the separation of sister chromatids called equational division. however, during meiosis, the meiotic cohesin rec8 mainly replaces rad21 along the entire chromosomes; one round of dna replication is followed by two rounds of nuclear division, which results in four haploid nuclei or gametes. in the first division of meiosis (meiosis i), homologous chromosomes connected by chiasmata are captured from the opposite poles, whereas sisters are captured from the same pole (mono-orientation of kinetochores). at the onset of anaphase i, rec8 is cleaved by separase along the arm regions, but protected at centromeres until metaphase ii. thus, "mono-orientation" and "cohesion protection" are two hallmarks of meiotic kinetochore function, both being established depending on rec8. these meiosis-specific functions of rec8 are not possessed by the rad21 protein, although both proteins as a klein subunit of the cohesion complex possess similar function for establishing sister chromatid cohesion. here, i investigated the organization of the meiosis-specific functional domain of rec8 by replacing various regions of the rec8 protein with the corresponding regions of the rad21 protein.

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