Surface lipids in nematodes are developmentally dependent and species-specific

Abstract

Chemical signalling facilitates organismal communication and coordinates physiological and behavioural processes. In nematodes, chemical signalling has focused on secreted molecules leaving the surface's communicative potential unexplored. Utilising 3D-OrbiSIMS surface-sensitive mass spectrometry, we directly characterise the molecular surface composition of Caenorhabditis elegans and Pristionchus pacificus. Their surfaces consist of a complex, lipid-dominated landscape with distinct developmental profiles and species-specific characteristics. These surface-anchored chemistries depend on the peroxisomal fatty acid beta-oxidation component daf-22 and are essential for interaction-based behaviours including predation and kin-recognition. Specific lipid molecules identified as putative kin-recognition associated surface components include diglyceride (DG O-50:13), ceramide phosphate (CerP 41:1;O3), and hexosylceramide (HexCer 40:2;O3). Thus, we reveal the nematode surface is a dynamic signalling interface, pivotal for deciphering molecular mechanisms regulating development, identity and contact-dependent behaviour.