Interacting genes required for pharyngeal excitation by motor neuron MC in Caenorhabditis elegans.
Interacting genes required for pharyngeal excitation by motor neuron MC in Caenorhabditis elegans.
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DOI：
10.1093/genetics/141.4.1365
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发表时间：
1995-12
期刊：
影响因子：
3.3
通讯作者：
D. Raizen;Raymond Y. N. Lee;L. Avery
中科院分区：
文献类型：
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作者：
D. Raizen;Raymond Y. N. Lee;L. Avery
我们研究了秀丽隐杆线虫咽部兴奋的控制。通过激光消融咽部神经系统的亚群，我们发现MC神经元型对于快速咽泵是必要的，并且可能是足够的。咽电图显示MC传递兴奋性突触后电位，提示MC具有咽泵的神经源性起搏器作用。乙酰胆碱(ACh)释放所需基因的突变和尼古丁ACh受体(NAChR)的拮抗剂降低了泵送速率，表明nAChR是MC传递所必需的。为了确定MC神经传递所需的基因，我们筛选了导致泵送缓慢但没有其他缺陷的突变。两个基因Eat-2和Eat-18的突变消除了MC的神经传递。功能获得的EAT-18突变ad820sd和假定的功能丧失的Eat-18突变AD1110都减少了对nAChR激动剂尼古丁和卡巴胆碱的咽肌兴奋，这表明Eat-18是咽部nAChR功能所必需的。EAT-2基因的14个隐性突变可分为5个互补型。我们发现EAT-2和EAT-18之间的等位基因特异性遗传相互作用与EAT-2的互补类别相关。我们认为EAT-18和EAT-2在参与咽部nAChR功能的多亚单位蛋白复合体中发挥作用。
We studied the control of pharyngeal excitation in Caenorhabditis elegans. By laser ablating subsets of the pharyngeal nervous system, we found that the MC neuron type is necessary and probably sufficient for rapid pharyngeal pumping. Electropharyngeograms showed that MC transmits excitatory postsynaptic potentials, suggesting that MC acts as a neurogenic pacemaker for pharyngeal pumping. Mutations in genes required for acetylcholine (ACh) release and an antagonist of the nicotinic ACh receptor (nAChR) reduced pumping rates, suggesting that a nAChR is required for MC transmission. To identify genes required for MC neurotransmission, we screened for mutations that cause slow pumping but no other defects. Mutations in two genes, eat-2 and eat-18, eliminated MC neurotransmission. A gain-of-function eat-18 mutation, ad820sd, and a putative loss-of-function eat-18 mutation, ad1110, both reduced the excitation of pharyngeal muscle in response to the nAChR agonists nicotine and carbachol, suggesting that eat-18 is required for the function of a pharyngeal nAChR. Fourteen recessive mutations in eat-2 fell into five complementation classes. We found allele-specific genetic interactions between eat-2 and eat-18 that correlated with complementation classes of eat-2. We propose that eat-18 and eat-2 function in a multisubunit protein complex involved in the function of a pharyngeal nAChR.