Zoology Department, University of Texas, Austin, Texas 78712.
Genetics. 1976 Jan;82(1):19-24. doi: 10.1093/genetics/82.1.19.
Analysis of systematic scan data from microsporocyte smear preparations suggests that cells with a crossover in a specific region tend to be geographically clustered to some extent within anthers. Crossover classes observed include single crossovers within a heterozygous inversion, three-strand double crossovers within and proximal to the inversion, and four-strand double crossovers within the inversion. Evidence for clustering within scans of cells of the first two classes is reported, but results are inconclusive for the third class. No evidence for within-scan correlation of frequencies of any two of the crossover classes was found. It is inferred that a large part of the variability in crossover frequency observed is probably due to factors which alter crossover interference. Implications related to the frequency and distribution of crossover sites are discussed.
从花粉母细胞抹片中的系统扫描数据的分析表明，在特定区域发生交叉的细胞在花药内某种程度上倾向于在空间上聚集。观察到的交叉类型包括杂合倒位内的单个交叉、倒位内和附近的三链双链交叉以及倒位内的四线双链交叉。报道了前两类细胞扫描中存在聚集的证据，但对于第三类结果尚无定论。没有发现任何两个交叉类型频率之间在扫描内存在相关性的证据。推断观察到的交叉频率的可变性很大程度上可能归因于改变交叉干扰的因素。讨论了与交叉位点频率和分布相关的含义。
