A Caenorhabditis elegans RNA polymerase II gene, ama-1 IV, and nearby essential genes.
A Caenorhabditis elegans RNA polymerase II gene, ama-1 IV, and nearby essential genes.
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秀丽隐杆线虫 RNA 聚合酶 II 基因、ama-1 IV 和附近的必需基因。
DOI：
10.1093/genetics/118.1.61
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发表时间：
1988
期刊：
影响因子：
3.3
通讯作者：
Riddle,DL
中科院分区：
文献类型：
--
作者：
Rogalski,TM;Riddle,DL
秀丽线虫RNA聚合酶II的Amanitin结合亚基由ama-1基因编码，位于dpy-13 IV右侧约0.05个图位单位。在被检测的六个甲烷磺酸乙酯诱导的突变体中，有两个在胚胎发育后期被阻止。其中之一是一个很大的缺陷mDf9，但第二个可能是一个新的点突变。其他四个突变体是亚型，可能会产生具有一些残留功能的改变的RNA聚合酶II酶。其中两个突变株在20度的温度下发育成不育的成虫，但在25度的温度下作为幼虫停滞，另外两个突变株在20度的温度下可育，在25度的温度下不育。对成体不育突变体ama-1(M118m238ts)进行的温度漂移实验表明，性腺发生后期有一个温度敏感期，以产卵开始为中心。在25度的温度下，胚胎后发育会减慢30%。相比之下，AMA-1的Amanitin抗性等位基因对发育率或生育力的影响很小。在围绕ama-1的4.5个图谱单元中，我们已经确定了15个必需基因，以及4个伽马射线诱导的缺陷和包括ama-1基因的两个重复。更大的复制，mDp1，可能包括IV染色体的整个左臂，它以较低的频率与正常同源物重组。最小的缺失，mDf10，除了三个已识别的基因：let-278，dpy-13和ama-1之外，补充了所有已识别的基因，这三个基因定义的间隔只有0.1个图谱单位。MDf10纯合子的最终表型是第一幼虫阶段的发育停滞，表明有足够的母体RNA聚合酶II完成胚胎发育。
The amanitin-binding subunit of RNA polymerase II in Caenorhabditis elegans is encoded by the ama-1 gene, located approximately 0.05 map unit to the right of dpy-13 IV. Using the amanitin-resistant ama-1(m118) strain as a parent, we have isolated amanitin-sensitive mutants that carry recessive-lethal ama-1 alleles. Of the six ethyl methanesulfonate-induced mutants examined, two are arrested late in embryogenesis. One of these is a large deficiency, mDf9, but the second may be a novel point mutation. The four other mutants are hypomorphs, and presumably produce altered RNA polymerase II enzymes with some residual function. Two of these mutants develop into sterile adults at 20 degrees but are arrested as larvae at 25 degrees, and two others are fertile at 20 degrees and sterile at 25 degrees. Temperature-shift experiments performed with the adult sterile mutant, ama-1(m118m238ts), have revealed a temperature-sensitive period that begins late in gonadogenesis and is centered around the initiation of egg-laying. Postembryonic development at 25 degrees is slowed by 30%. By contrast, the amanitin-resistant allele of ama-1 has very little effect on developmental rate or fertility. We have identified 15 essential genes in an interval of 4.5 map units surrounding ama-1, as well as four gamma-ray-induced deficiencies and two duplications that include the ama-1 gene. The larger duplication, mDp1, may include the entire left arm of chromosome IV, and it recombines with the normal homologue at a low frequency. The smallest deficiency, mDf10, complements all but three identified genes: let-278, dpy-13 and ama-1, which define an interval of only 0.1 map unit. The terminal phenotype of mDf10 homozygotes is developmental arrest during the first larval stage, suggesting that there is sufficient maternal RNA polymerase II to complete embryonic development.