Cross Talk with the GAR-3 Receptor Contributes to Feeding Defects in Caenorhabditis elegans eat-2 Mutants

Genetics: A Periodical Record of Investigations Bearing on Heredity and Variation

Alena A. Kozlova^1¹ 

[1] Department of Biological Sciences, University of Illinois at Chicago, Illinois 60607^1

关键词: C. elegans;    pharynx;    GCaMP3;    nicotinic acetylcholine receptor;    muscarinic acetylcholine receptor;    peristalsis;    life span;    feeding;   

DOI  :  10.1534/genetics.119.302053

学科分类：医学（综合）

来源: Genetics Society of America

【 摘 要 】

Precise signaling at the neuromuscular junction (NMJ) is essential for proper muscle contraction. In the Caenorhabditis elegans pharynx, acetylcholine (ACh) released from the MC and M4 motor neurons stimulates two different types of contractions in adjacent muscle cells, termed pumping and isthmus peristalsis. MC stimulates rapid pumping through the nicotinic ACh receptor EAT-2 , which is tightly localized at the MC NMJ, and eat-2 mutants exhibit a slow pump rate. Surprisingly, we found that eat-2 mutants also hyperstimulated peristaltic contractions, and that they were characterized by increased and prolonged Ca²⁺ transients in the isthmus muscles. This hyperstimulation depends on cross talk with the GAR-3 muscarinic ACh receptor as gar-3 mutation specifically suppressed the prolonged contraction and increased Ca²⁺ observed in eat-2 mutant peristalses. Similar GAR-3-dependent hyperstimulation was also observed in mutants lacking the ace-3 acetylcholinesterase, and we suggest that NMJ defects in eat-2 and ace-3 mutants result in ACh stimulation of extrasynaptic GAR-3 receptors in isthmus muscles. gar-3 mutation also suppressed slow larval growth and prolonged life span phenotypes that result from dietary restriction in eat-2 mutants, indicating that cross talk with the GAR-3 receptor has a long-term impact on feeding behavior and eat-2 mutant phenotypes.

【 授权许可】

CC BY