偶线期:减数分裂前期Ⅰ的第二个时期,此期染色质进一步凝集,同源染色体(homologous chromosomes)发生配对,称为联会(synapsis),所以此期又称配对期(pairing stage)。此期合成Zyg-DNA(也称偶线期DNA)且活跃转录。Zyg-DNA属于基因组DNA,故减数分裂中基因组DNA的复制完成于偶线期。
晚偶线期出现染色体互锁现象;
前期可被分为连续的阶段:细线期、偶线期、粗线期、双线期和终变期。
Prophase may be divided into successive stages termed leptotene, zygotene, pachytene, diplotene, and diakinesis.
偶线期时,以同源染色体活跃的、特定的配对(联会)为特征,形成了单倍数的二价染色体。
Synapsis (pairing) the association of homologous chromosomes during the prophase stage of meiosis that leads to the production of a haploid number of bivalents.
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