Expression and localization of adreno-corticotropic-hormone (ACTH) and NeuN in myxomycete plasmodia

Abstract

The myxomycete life-cycle mainly consists of cellular uninucleate amoeboflagellates, stationary spore-bearing sporophores, and acellular multinucleate plasmodia. The plasmodium is able to regulate complex behavior, but no differentiated signaling structures have been detected. As a basal lineage eukaryote, research on any neuron-like substances may contribute to our understanding of the origin of the nervous system in complex organisms. We examined the expression and localization of the neuropeptide adreno-cortico-tropic-hormone (ACTH) and the neuroprokaryotic protein (NeuN) in two species of Physarum under different culture conditions were studied by immunofluorescence and western blotting. ACTH was expressed in the cytoplasm of the plasmodium of Physarum flavicomum, and NeuN was expressed in the nuclear membrane of the plasmodium of P. polycephalum and in the cytoplasm of that of P. flavicomum. This demonstrates the occurrence of neuropeptides in the myxomycete plasmodium for the first time and contributes to the understanding of intercellular communication in Myxomycetes.