Chiasma distribution at diakinesis in the normal human male.
Chiasma distribution at diakinesis in the normal human male.
复制标题
正常人类男性恒动期的交叉分布。
作者：
M. Hultén
使用地衣因、Q 和 C 技术三重染色的细胞对一名男性受试者研究了终变时的交叉分布。获得的证据支持沿染色体臂的交叉之间存在干扰，即使考虑到每个二价体出现一个专性交叉。没有迹象表明同一细胞中不同常染色体之间存在交叉竞争。染色体臂内的交叉分布与在其他生物体中观察到的非常相似，在双线期期间没有或只有中等交叉运动并且交叉频率没有减少。讨论了这些发现与交叉频率估计和解释有关交叉原始位置及其相互关系的不同模型的相关性。双线期至终变期的交叉平均数通常用作估计基因组总长度的细胞学测量。该估计基于这样的假设：遗传交叉和交叉之间存在一一对应关系（由 HENDERSON 1969a 和 WHITEHOUSE 审查）
The chiasma distribution at diakinesis was investigated in one human male subject using cells triple-stained by the orcein, Q- and C-techniques. Evidence was obtained in favour of interference between chiasmata along the chromosome arms, even when the occurrence of one obligate chiasma per bivalent was taken into account. There was no indication of competition for chiasmata between different autosomes in the same cell. The chiasma distribution within chromosome arms was very similar to that observed in other organisms with no or only a moderate chiasma movement and no reduction in chiasma frequency during diplotene. The relevance of these findings for the estimation of the crossover frequency and for the interpretation of different models concerning the original location of chiasmata and their interrelation is discussed. The mean number of chiasmata at diplotene to diakinesis is generally used as a cytological measure for the estimation of the total length of the genome. The estimation is based on the hypothesis that there is a one to one correspondence between genetic crossing over and chiasmata (reviewed by HENDERSON 1969a and WHITEHOUSE