Choline acetyltransferase-deficient mutants of the nematode Caenorhabditis elegans.
Choline acetyltransferase-deficient mutants of the nematode Caenorhabditis elegans.
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DOI：
10.1093/genetics/106.2.227
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发表时间：
1984-02
期刊：
影响因子：
3.3
通讯作者：
J. Rand;R. L. Russell
中科院分区：
文献类型：
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作者：
J. Rand;R. L. Russell
我们已经确定了五个独立的等位基因突变，定义了基因 cha-1，导致秀丽隐杆线虫胆碱乙酰转移酶 (ChAT) 活性降低。其中四个突变等位基因，当纯合时，会导致 ChAT 减少超过 98%，以及行为不协调、体积小、生长缓慢和对胆碱酯酶抑制剂具有抗性的隐性表型。第五个等位基因纯合的动物保留了大约 10% 的野生型酶水平；从该突变体纯化的酶改变了胆碱和乙酰辅酶A的Km值，并且比野生型酶更不耐热。这些定性改变与基因剂量数据一起表明 cha-1 是 ChAT 的结构基因。 cha-1 已被定位到连锁组 IV 的左臂，并且位于基因 unc-17 的 0.02 个图谱单位内，该基因的突变等位基因导致除 ChAT 缺陷外的 cha-1 突变体的所有表型。对 cha-1 和 unc-17 等位基因的广泛互补研究揭示了复杂的互补模式，表明这两个基因座可能是单个复杂基因的一部分。
We have identified five independent allelic mutations, defining the gene cha-1, that result in decreased choline acetyltransferase (ChAT) activity in Caenorhabditis elegans. Four of the mutant alleles, when homozygous, lead to ChAT reductions of greater than 98%, as well as recessive phenotypes of uncoordinated behavior, small size, slow growth and resistance to cholinesterase inhibitors. Animals homozygous for the fifth allele retain approximately 10% of the wild-type enzyme level; purified enzyme from this mutant has altered Km values for both choline and acetyl-CoA and is more thermolabile than the wild-type enzyme. These qualitative alterations, together with gene dosage data, argue that cha-1 is the structural gene for ChAT. cha-1 has been mapped to the left arm of linkage group IV and is within 0.02 map unit of the gene unc-17, mutant alleles of which lead to all of the phenotypes of cha-1 mutants except for the ChAT deficiency. Extensive complementation studies of cha-1 and unc-17 alleles reveal a complex complementation pattern, suggesting that both loci may be part of a single complex gene.