Chromosome behavior and the molecular basis of meiosis

Meiosis is a distinctcell division pathway in gamete formation in sexually reproducing organisms. During meiosis, the chromosomes undergo only one round of replication, followed by two rounds of cell division to produce haploid gametes. The behaviorsof chromosomes during meiosis I,including pairing, synapsis, recombination, and segregation of homologous chromosomes, are the most distinguishing features of meiosis. These behaviors arebased on the formation and repair of programmed DNA double-strand breaks in early meiotic prophase I. In this paper, we summarize the most important chromosome behaviors during meiosis and discuss the possible molecular mechanisms underlying these behaviors.