The Mass Spectrometry society of Japan - The 68th Annual Conference on Mass Spectrometry, Japan

Abstract

Oral Sessions

Day 3, June 24(Fri.) 15:40-16:00 Room A (Main Hall)

Peptidomics and single cell transcriptome reveal the evolutional origin of nervous system

(1OIST, 2Univ. Tsukuba)
oEisuke Hayakawa1, Christine Guzman1, Osamu Horiguchi1, Chihiro Kawano1, Ryotaro Nakamura1, Kazuo Inaba2, Hiroshi Watanabe1

Nervous system has a deep evolutionary root and plays critical roles in transmitting information and coordinating behaviors in the life of animals. Understanding the diversification and origin of nervous system and its underlying molecular machinery is therefore particularly important. Although the genomic information of basal metazoans has been accumulated in recent years, physiological and molecular origins of neurons are still largely unclear. To identify the molecular properties of ancient nervous system, we focused on neuropeptides which are the most common neurotransmitters in animal kingdom. We systematically analyzed neuropeptides employing mass spectrometry-based peptidomics, together with single cell transcriptome data to dissect the molecular machineries of neuropeptide-related functions for early-branching lineages Cnidaria, Porifera and Ctenophora. Using nano-LC based extensive MS/MS analytical platform, we successfully identified a number of novel neuropeptides from Ctenophora, the most ancient phylum possessing nervous system, for the first time. The identified neuropeptides were then incorporated into the single cell transcriptome data, to identify the cell clusters of functional neurons. Neuropeptide expressing cell clusters co-express vast majority of genes essential for the processing of neuropeptides known in Bilateria. These strong similarities of molecular properties between Ctenophora and other metazoans indicate the common evolutionary origin of metazoan nervous systems.