An increase in the X-linked lethal mutation rate associated with an unstable locus in Drosophila melanogaster.
An increase in the X-linked lethal mutation rate associated with an unstable locus in Drosophila melanogaster.
复制标题
X连锁致死突变率的增加与果蝇不稳定基因座相关。
DOI：
10.1093/genetics/98.2.291
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发表时间：
1981
期刊：
影响因子：
3.3
通讯作者：
Simmons,MJ
中科院分区：
文献类型：
--
作者：
Raymond,JD;Simmons,MJ
研究了X染色体上烧焦刚毛位点的不稳定等位基因的行为与同一染色体上致命突变的发生之间的关系。不稳定的等位基因，弱染色（snw），是在杂种发育不全的P-M系统的控制下，在M细胞型中，以高速率突变为极端染色（sne）和野生型（sn+）。nwallele以这种方式突变的染色体以3%的比率持续致死突变;而那些nwallele明显保持不变的染色体以较低的比率（1.3%）获得致死突变。这些值之间的显著差异表明snw不稳定现象和X连锁致死突变诱导之间的统计学一致性。这种巧合可以通过假设在烧焦的基因座上的突变有时会释放出一种能够重新插入染色体其他地方的遗传元件来解释。或者，snw不稳定性和致死诱导可能相关，因为它们是一个共同原因的影响，也许是一些突变诱导物质以不同的量存在于发育不良苍蝇的生殖细胞中。发生在nwallele突变的染色体上的死亡优先接近烧焦。nwandsn+染色体上的致死量在图上没有显示出这种浓度。所有三种类型的致死染色体的样品的细胞学分析表明，除了一个例外，有没有可检测到的断裂在烧焦的位点本身。单一的情况下，断裂在烧焦与任何变化，烧焦的表型。因此，snw的不稳定性显然不涉及烧焦位点的可检测的断裂，或者如果涉及，这种断裂不是常见事件。
The behavior of an unstable allele of the singed-bristle locus on theXchromosome was studied in connection with the occurrence of lethal mutations on that same chromosome. The unstable allele, weak singed (snw), is under the control of theP-Msystem of hybrid dysgenesis and, in theMcytotype, mutates secondarily to extreme singed (sne) and to wild type (sn+) at high rates. Chromosomes whosesnwallele had mutated in this fashion sustained lethal mutations at a rate of 3%; whereas, those whosesnwallele had apparently remained unchanged, acquired lethals at a lower rate, 1.3%. The significant difference between these values indicates a statistical coincidence between the phenomena ofsnwinstability andX-linked lethal mutation induction. This coincidence can be explained by postulating that mutations at the singed locus sometimes release a genetic element capable of reinserting elsewhere in the chromosome. Alternately,snwinstability and lethal induction might be associated because they are the effects of a common cause, perhaps some mutation-inducing substance present in various amounts in the germ cells of dysgenic flies.—The lethals that occurred on chromosomes whosesnwallele had mutated tosnemapped preferentially close to singed. The lethals on thesnwandsn+chromosomes did not show this concentration on the map. Cytological analysis of samples of all three types of lethal chromosomes indicated that, with one exception, there was no detectable breakage at the singed locus itself. The single instance of breakage at singed was not associated with any change in the singed phenotype. Thus, the instability ofsnwapparently does not involve detectable breakage of the singed locus, or if it does, this breakage is not a common event.