Narain Y, Fredga K
Department of Genetics, Uppsala University, Sweden.
Cytogenet Cell Genet. 1997;78(3-4):253-9. doi: 10.1159/000134668.
Adult male common shrews from the Uppsala and Hällefors Robertsonian chromosomal races and hybrids were collected from the area of Surahammar in Sweden. Meiosis and fertility of hybrid (complex heterozygotes) and nonhybrid (homozygotes) individuals were compared based on an analysis of chromosomal interactions and synapsis at pachytene, chiasma characteristics at diakinesis, and germ-cell death. No individuals suffered severe germ-cell loss, and the differences found among the Uppsala and Hällefors homozygotes and the hybrids were not significant. In complex heterozygotes, ring configurations of four elements were observed at meiosis I, with one chiasma per chromosome arm. Abnormal rings were frequent at pachytene, but interactions between the ring and other chromosomes were seldom found. There is no indication from this study of a differential fertility between homozygotes and ring IV-forming complex heterozygotes in males.
来自瑞典苏拉哈马尔地区的成年雄性普通鼩鼱，涵盖乌普萨拉和黑勒福斯罗伯逊染色体种族及其杂种。基于对粗线期染色体相互作用和联会、终变期交叉特征以及生殖细胞死亡情况的分析，比较了杂种（复合杂合子）和非杂种（纯合子）个体的减数分裂和生育能力。没有个体出现严重的生殖细胞损失，并且在乌普萨拉和黑勒福斯纯合子与杂种之间发现的差异并不显著。在复合杂合子中，减数分裂I期观察到四个元件的环状结构，每条染色体臂有一个交叉。粗线期异常环很常见，但很少发现环与其他染色体之间的相互作用。这项研究没有表明雄性纯合子和形成环IV的复合杂合子之间存在生育差异。
