Broverman S A, Meneely P M
Fred Hutchinson Cancer Research Center, Seattle, Washington 98104.
Genetics. 1994 Jan;136(1):119-27. doi: 10.1093/genetics/136.1.119.
Recessive mutations in three autosomal genes, him-1, him-5 and him-8, cause high levels of X chromosome nondisjunction in hermaphrodites of Caenorhabditis elegans, with no comparable effect on autosomal disjunction. Each of the mutants has reduced levels of X chromosome recombination, correlating with the increase in nondisjunction. However, normal or elevated levels of recombination occur at the end of the X chromosome hypothesized to contain the pairing region (the left end), with recombination levels decreasing in regions approaching the right end. Thus, both the number and the distribution of X chromosome exchange events are altered in these mutants. As a result, the genetic map of the X chromosome in the him mutants exhibits a clustering of genes due to reduced recombination, a feature characteristic of the genetic map of the autosomes in non-mutant animals. We hypothesize that these him genes are needed for some processive event that initiates near the left end of the X chromosome.
三个常染色体基因him-1、him-5和him-8中的隐性突变，会导致秀丽隐杆线虫雌雄同体中X染色体的不分离水平升高，而对常染色体分离没有类似影响。每个突变体的X染色体重组水平都有所降低，这与不分离的增加相关。然而，在假定包含配对区域的X染色体末端（左端）会发生正常或升高水平的重组，而在接近右端的区域重组水平则降低。因此，这些突变体中X染色体交换事件的数量和分布都发生了改变。结果，him突变体中X染色体的遗传图谱由于重组减少而呈现出基因聚集现象，这是未突变动物常染色体遗传图谱的一个特征。我们推测，这些him基因对于在X染色体左端附近启动的某些连续事件是必需的。
