Maguire M P, Riess R W, Paredes A M
Department of Zoology, University of Texas, Austin 78712.
Genome. 1993 Oct;36(5):797-807. doi: 10.1139/g93-105.
Homozygotes for the dsy1 desynaptic mutant of maize show massive failure of chiasma maintenance during diplotene and diakinesis. Although some chiasmata persist until anaphase I in most microsporocytes expressing this mutant, homozygotes are completely or nearly completely sterile, owing apparently to disjunctive irregularities. Pachytene synaptic errors and some synaptic failure also are found, but recombination nodules are common in homologously synapsed regions, and equational separation of a heterozygous knob into univalents or open arms at diakinesis clearly demonstrates that chiasma failure occurs following crossing-over. A wider than normal synaptonemal complex central region and uniform apparent weakness of central region cross connections to spreading procedures strongly suggest the presence of a genetic lesion in a synaptonemal complex central region component. The dsy1 mutant may provide an especially important source of material for molecular studies on the nature of chiasma maintenance mechanism.
玉米dsy1去联会突变体的纯合子在双线期和终变期表现出大量交叉维持失败的情况。尽管在大多数表达该突变体的小孢子母细胞中，一些交叉会持续到后期I，但纯合子完全或几乎完全不育，显然是由于分离不规则所致。也发现了粗线期联会错误和一些联会失败，但重组结节在同源联会区域很常见，并且在终变期将杂合着丝粒不等分到单价体或开放臂中，清楚地表明交叉失败发生在交换之后。比正常宽的联会复合体中央区域以及中央区域交叉连接到伸展过程的明显均匀弱点，强烈表明联会复合体中央区域成分存在遗传损伤。dsy1突变体可能为交叉维持机制本质的分子研究提供特别重要的材料来源。
