Three‐dimensional reconstruction of the pharyngeal gland cells in the predatory nematode Pristionchus pacificus. (12th September 2017)

• Record Type: Journal Article
• Authors: Riebesell, Metta; Sommer, Ralf J.
• Is Part Of: Journal of morphology. Volume 278:Number 12(2017)
• Page Start: 1656
• Page End: 1666
• Publication Date: 2017-09-12
• Subjects: Caenorhabditis elegans -- gland cells -- pharynx -- predatory feeding -- Pristionchus pacificus; Morphology -- Periodicals; Physiology -- Periodicals; Anatomy -- Periodicals; 571.3
• DOI: 10.1002/jmor.20739
• Languages: English
• ISSNs: 0362-2525

Abstract

Abstract: Pristionchus pacificus is a model system in evolutionary biology and for comparison to Caenorhabditis elegans . As a necromenic nematode often found in association with scarab beetles, P. pacificus exhibits omnivorous feeding that is characterized by a mouth‐form dimorphism, an example of phenotypic plasticity. Eurystomatous animals have a dorsal and a sub‐ventral tooth enabling predatory feeding on other nematodes whereas stenostomatous animals have only a dorsal tooth and are microbivorous. Both mouth forms of P. pacificus, like all members of the Diplogastridae family, lack the grinder in the terminal bulb of the pharynx resulting in a fundamentally different organization of several pharynx‐associated structures. Here, we describe the three‐dimensional reconstruction of the pharyngeal gland cells in P. pacificus based on serial transmission electron microscopical analysis of 2527 sections of 50 nm thickness. In comparison to C. elegans, P. pacificus lacks two gland cells (g2) usually associated with grinder function, whereas the three gland cells of g1 (g1D, g1VL, and g1VR) are very prominent. The largest expansion is seen for g1D, which has an anterior process that opens into the buccal cavity through a canal in the dorsal tooth. We provide the morphological description and fine structural analysis of the P. pacificus gland cells, the behavior of the pharynx and preliminary insight into exocytosis of gland cell vesicles in P. pacificus . Abstract : Three‐dimensional reconstruction of the pharyngeal gland cells in the predatory nematode Pristionchus pacificus . In comparison to Caenorhabditis elegans, P. pacificus has only three gland cells, all of which show massive expansions of their cell bodies. The dorsal gland cell has a long anterior process that opens through the dorsal tooth into the buccal cavity, whereas the two ventral glands open into the posterior metacorpus.