...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Molecular and Cellular Biology >Heat-sensitive mutant strain of Neurospora crassa, 4M(t), conditionally defective in 25S ribosomal ribonucleic acid production.
【24h】

Heat-sensitive mutant strain of Neurospora crassa, 4M(t), conditionally defective in 25S ribosomal ribonucleic acid production.

机译：Neurospora crassa的热敏突变株4M（t）在25S核糖体核糖核酸生产中有条件地存在缺陷。

获取原文
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

A heat-sensitive mutant strain of Neurospora crassa, 4M(t), was studied in an attempt to define its molecular lesion. The mutant strain is inhibited in conidial germination and mycelial extension at the nonpermissive temperature (37 degrees C). Macromolecular synthesis studies showed that both ribonucleic acid (RNA) and protein syntheses are inhibited when 4-h cultures are shifted from 20 to 37 degrees C. Density gradient analysis of ribosomal subunits made at 37 degrees C indicated that strain 4M(t) is deficient in the accumulation of 60S ribosomal subunits in that the ratio of 60S/37S subunits was 0.29:1 compared with 1.6:1 for the parental strain. This phenotype was shown to be the result of a slow rate of processing of, and a deficiency in the amount of, the immediate precursor to 25S ribosomal RNA (the large RNA of the 60S subunit) in the sequence of events constituting the production of mature ribosomal RNAs from the primary transcript of the ribosomal deoxyribonucleic acid, the precursor ribosomal RNA molecule. Analysis of polysomes suggested that the heat-sensitive gene product might function in both the assembly and the function of the 60S ribosomal subunit, since there was a smaller proportion of newly made 60S subunits synthesized at 37 degrees C in the polysome region of the gradients than in the monosome-plus-subunit region. The ribosomal RNA processing defect is apparently responsible for the observed defects in germination and macromolecular synthesis at 37 degrees C, but the precise molecular lesion is not known. On the basis of these results, the heat-sensitive mutant allele in the 4M(t) strain is considered to define the rip1 (ribosome production) gene locus.
机译：为了确定其分子损伤，研究了一种神经孢霉热敏感突变株4M（t）。在不允许的温度（37摄氏度）下，突变菌株的分生孢子萌发和菌丝体延伸受到抑制。高分子合成研究表明，当4小时培养物从20摄氏度移至37摄氏度时，核糖核酸（RNA）和蛋白质合成均受到抑制。在37摄氏度下进行的核糖体亚基的密度梯度分析表明，菌株4M（t）不足在60S核糖体亚基的积累中，60S / 37S亚基的比例为0.29：1，而亲本菌株为1.6：1。该表型显示为25S核糖体RNA（60S亚基的大RNA）的直接前体的加工速度慢和数量不足的结果，该事件的顺序是构成成熟产物的事件序列核糖体脱氧核糖核酸（核糖体RNA的前体）的初级转录本中的核糖体RNA。对多核糖体的分析表明，热敏感的基因产物可能在60S核糖体亚基的组装和功能中起作用，因为在梯度多核糖体区中在37°C合成的新产生的60S亚基比在单核糖体加亚基区域。核糖体RNA加工缺陷显然是造成37℃下发芽和大分子合成中观察到的缺陷的原因，但确切的分子病变尚不清楚。根据这些结果，认为4M（t）菌株中的热敏突变体等位基因定义了rip1（核糖体生成）基因位点。

著录项

相似文献

  • 外文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号