Tell the Difference Between Mitosis and Meiosis: Interplay Between Chromosomes, Cytoskeleton, and Cell Cycle Regulation

Abstract

Meiosis is a specialized style of cell division conserved in eukaryotes, particularly designed for the production of gametes. A huge number of studies to date have demonstrated how chromosomes behave and how meiotic events are controlled. Yeast substantially contributed to the understanding of the molecular mechanisms of meiosis in the past decades. Recently, evidence began to accumulate to draw a perspective landscape showing that chromosomes and microtubules are mutually influenced: microtubules regulate chromosomes, whereas chromosomes also regulate microtubule behaviors. Here we focus on lessons from recent advancement in genetical and cytological studies of the fission yeast Schizosaccharomyces pombe, revealing how chromosomes, cytoskeleton, and cell cycle progression are organized and particularly how these are differentiated in mitosis and meiosis. These studies illuminate that meiosis is strategically designed to fulfill two missions: faithful segregation of genetic materials and production of genetic diversity in descendants through elaboration by meiosis-specific factors in collaboration with general factors.

Aurora B/C-dependent phosphorylation promotes Rec8 cleavage in mammalian oocytes

“…Our data, however, do not yet show that endogenous Rec8 is indeed phosphorylated in oocyte meiosis I in an Aurora B/C-dependent manner. In meiosis I, cohesin on chromosome arms is removed during the first division to allow separation of chromosomes, whereas cohesin in the centromere region is protected to maintain sister chromatids together until meiosis II [1,2]. Therefore, we expected endogenous Rec8 to be phosphorylated on arms in meiosis I, and in the centromere region in meiosis II.…”

“…

To generate haploid gametes, cohesin is removed in a step-wise manner from chromosome arms in meiosis I and the centromere region in meiosis II, to segregate chromosomes and sister chromatids, respectively. Meiotic cohesin removal requires cleavage of the meiosis-specific kleisin subunit Rec8 by the protease Separase [1,2]. In yeast, Rec8 is kept in a non-phosphorylated state by the action of PP2A-B56, which is localised to the centromere region, thereby preventing cohesin removal from this region in meiosis I[3-5].

…”

Spatiotemporal Dynamic Regulation of Organelles During Meiotic Development, Insights From Fungi

“…Studies conducted in fungi have provided essential knowledge about the developmental processes of sexual reproduction, including karyogamy ( Rose, 1996 ; Gibeaux and Knop, 2013 ) and meiosis (e.g., Marston and Amon, 2004 ; Zickler and Espagne, 2016 ; Grey and de Massy, 2021 ; Sato et al, 2021 ). Fungal meiotic differentiation often culminates with the formation of haploid meiotic spores ( Figure 1 ).…”

MeiosisOnline: A Manually Curated Database for Tracking and Predicting Genes Associated With Meiosis

“…Meiosis, the process to generate daughter cells with an intact, haploid genome through one round of DNA replication followed by two rounds of cell division, is a basic feature of sexual reproductive organisms (Gerton and Hawley, 2005;Miller et al, 2013;Bolcun-Filas and Handel, 2018;Biswas et al, 2021). Compared with mitosis, meiosis is characterized by homologous chromosome separation, which ensures the genetic integrity of all daughter cells (Sato et al, 2021). A series of biological processes would take place during meiosis prophase I to guarantee the formation and repair of programmed meiotic DNA double-strand breaks (DSBs) and the pair and synapsis between homologous chromosomes, as well as the formation of meiotic crossovers (Handel and Schimenti, 2010;Baudat et al, 2013;Gray and Cohen, 2016;Ranjha et al, 2018;Jiao et al, 2020;Li et al, 2021).…”