Neuromuscular target recognition by a homophilic interaction of connectin cell adhesion molecules in Drosophila.
Drosophila Connectin (CON) is a cell surface protein of the leucine-rich repeat family. During the formation of neuromuscular connectivity, CON is expressed on the surface of a subset of embryonic muscles and on the growth cones and axons of the motoneurons that innervate these muscles, including primarily SNa motoneurons and their synaptic targets (lateral muscles). In vitro, CON can mediate homophilic cell adhesion. In this study, we generated transgenic lines that ectopically expressed CON on all muscles. In the transformant embryos and larvae, SNa motoneurons often inappropriately innervated a neighboring non-target muscle (muscle 12) that ectopically expressed CON. Furthermore, the ectopic synapse formation was dependent on the endogenous CON expression on the SNa motoneurons. These results show that CON can function as an attractive and homophilic target recognition molecule in vivo.
Nose
A
A
National Institute for Basic Biology, Myodaiji-cho, Ohazaki, Japan. nose@nibb.ac.jp
Umeda
T
T
Takeichi
M
M
D000818:Animals; D030801:Animals, Genetically Modified; D002448:Cell Adhesion; D015815:Cell Adhesion Molecules / Q000502:physiology*; D002462:Cell Membrane / Q000378:metabolism; D064211:Connectin; D004331:Drosophila melanogaster / Q000196:embryology*; D017261:Glycosylphosphatidylinositols; D009046:Motor Neurons / Q000166:cytology*; D009124:Muscle Proteins / Q000502:physiology*; D018482:Muscle, Skeletal / Q000196:embryology*; D018995:Myosin Heavy Chains / Q000235:genetics; D009469:Neuromuscular Junction / Q000196:embryology*; D011401:Promoter Regions, Genetic; D011494:Protein Kinases / Q000502:physiology*; D013569:Synapses / Q000648:ultrastructure
D015815:Cell Adhesion Molecules; D064211:Connectin; D017261:Glycosylphosphatidylinositols; D009124:Muscle Proteins; D011494:Protein Kinases; D018995:Myosin Heavy Chains