0 two chromosomes (= cell parts that control what an animal or plant is like), one from the father and one from the mother, that come together during meiosis (= cell division that happens as part of reproduction) -- 同源染色體
The first of these divisions is initiated in fetal life but the all important segregation of paired homologous chromosomes takes place after puberty.
The first requirement is for close pairing of homologous chromosomes, followed by recombination between non-sister chromatids.
The population of 1000 lines provided a first test of the feasibility of assembling a map with both simplex and duplex markers linking the homologous chromosomes.
Heterozygosity for an inversion induces a loop structure in paired homologous chromosomes and thus inversions are easy to detect cytologically.
Homologues separate, the first polar body is extruded and an interphase pronucleus' carrying one set of homologous chromosomes reforms.
After oocyte activation, homologous chromosomes segregate between the oocyte and the first polar body, and a diploid pronucleus-like nucleus reforms from the one set of dyads.
First, to achieve proper segregation, each pair of homologous chromosomes must be linked to each other to maintain a certain level of tension between them.
Balancer chromosomes can be used as a genetic tool to prevent crossing over (genetic recombination) between homologous chromosomes during meiosis.
