A recombinational hotspot at the triplo-lethal locus of Drosophila melanogaster.
A recombinational hotspot at the triplo-lethal locus of Drosophila melanogaster.
复制标题
果蝇三倍致死基因座的重组热点。
DOI：
10.1093/genetics/122.2.397
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发表时间：
1989
期刊：
影响因子：
3.3
通讯作者：
Christensen,AC
中科院分区：
文献类型：
--
作者：
Dorer,DR;Christensen,AC
在黑腹果蝇的基因组中只有一个位点，Tpl，是三倍致死的；它也是单倍致命的。先前的工作已经确定了3个Tpl的半胚等位基因，它们可以拯救携带Tpl重复的动物，但它们不像零突变或缺陷那样具有显性致命性。我们发现，当与野生型同源基因杂合时，所有三种次型等位基因都是重组的位点特异性热点。在Tpl亚型等位基因的存在下，侧翼标记ri和Ki之间的重组增加了6.5 ~ 10.5倍。发现Tpl和Ki之间的重组增加，而其他邻近区域的重组没有变化。使用等基因Tpl+对照，以及在突变染色体中使用侧翼间隔，使我们能够排除染色体间效应作为原因。我们还观察到在男性杂合子的Tpl次胚等位基因上发生减数分裂前重组。我们假设转座子是造成亚形态表型和高重组频率的原因。
In the genome of Drosophila melanogaster there is only one locus, Tpl, that is triplo-lethal; it is also haplo-lethal. Previous work has identified 3 hypomorphic alleles of Tpl which rescue animals carrying a duplication of Tpl, but which are not dominant lethals as null mutations or deficiencies would be. We have found that all three hypomorphic alleles act as site-specific hotspots for recombination when heterozygous with a wild-type homolog. Recombination between the flanking markers ri and Ki is increased 6.5-10.5-fold in the presence of Tpl hypomorphic alleles. The increased recombination was found to occur between Tpl and Ki, while recombination in other adjacent regions is unchanged. The use of isogenic Tpl+ controls, and the use of flanking intervals in the mutant chromosomes allows us to rule out the interchromosomal effect as a cause. We have also observed premeiotic recombination occurring at the Tpl hypomorphic alleles in male heterozygotes. We hypothesize that transposons are responsible for both the hypomorphic phenotype and the high frequency of recombination.