Departamento de Genética, Facultad de Biología, Universidad Complutense, 28040 Madrid, Spain.
Genetics. 1985 Dec;111(4):917-31. doi: 10.1093/genetics/111.4.917.
The use of telomeric C-bands in wheat-rye hybrids has made it possible to distinguish three types of wheat-wheat (1B(L)) and wheat-rye associations (a, end-to-end extremely distal; b, end-to-ed distal; and c, interstitial) between homoeologous chromosomes at different metaphase I stages (early, middle and late) and also to estimate the actual recombination frequencies for such associations at anaphase I. There was a decrease of the a and b association frequencies during the different metaphase I stages, whereas the c type remained without variation in all stages. A good fit between the frequencies of c associations at metaphase I and the number of recombinant chromosomes at anaphase I, assuming a maximum of one chiasma per bond, was found; however, there was no correspondence between metaphase I and anaphase I data when all associations (a + b + c) were considered. In addition, rye-rye homologous pairing was observed at metaphase I, but no evidence for rye-rye recombination was found at anaphase I. The results indicate that most of end-to-end (a and b) homoeologous and nonhomologous associations are actually nonchiasmatic and are a remnant of prophase pairing.
小麦-黑麦杂种中使用端粒 C 带使得在不同的中期 I 阶段（早期、中期和晚期）区分同源染色体之间的三种小麦-小麦（1B(L)) 和小麦-黑麦的关联（a，端到端极远端；b，端到端远端；和 c，中间）成为可能，也可以估计这些关联在后期 I 的实际重组频率。在不同的中期 I 阶段，a 和 b 关联频率下降，而 c 类型在所有阶段都没有变化。在中期 I 处 c 型关联的频率与后期 I 处重组染色体的数量之间存在良好的拟合，假设每个键的交叉数最多为 1 个；然而，当考虑所有关联（a + b + c）时，中期 I 和后期 I 数据之间没有对应关系。此外，在中期 I 观察到黑麦-黑麦同源配对，但在后期 I 未发现黑麦-黑麦重组的证据。结果表明，大多数端到端（a 和 b）的同源和非同源关联实际上是非交叉的，是前期配对的残余。
