Influence of symbiotic and non-symbiotic bacteria on pheromone production in Steinernema nematodes (Nematoda, Steinernematidae)

Abstract

In this study, we assessed the effect of symbiotic (cognate and noncognate) and non-symbiotic bacteria on ascaroside production of firstgeneration adults in two Steinernema spp.: S. carpocapsae All strain and S. feltiae SN strain. Each nematode species was reared under three bacterial scenarios: (1) cognate symbiotic, (2) non-cognate symbiotic strain and (3) non-cognate symbiotic species. Our results showed S. carpocapsae produced four quantifiable ascaroside molecules: asc-C5, asc-C6, asc-C7 and asc-C11, whereas in S. feltiae only three molecules were detected: asc-C5, asc-C7 and asc-C11. Bacterial conditions did not significantly affect the quantity of the secreted ascarosides in first-generation adults of S. carpocapsae. However, in S. feltiae, Xenorhabdus nematophila All strain influenced the production of two ascaroside molecules: asc-C5 and asc-C11.

CRISPR-Cas9 genome editing inSteinernemaentomopathogenic nematodes

“…A signature phenotype of the daf-22 mutation in nematodes is a defect in dauer larvae (paralleled stage of IJ) development, a process dependent on dauer pheromone production (Butcher et al, 2009; Cohen et al, 2022; Golden & Riddle, 1982; Markov et al, 2016). Entomopathogenic nematodes also produce ascarosides that affect IJ development and dispersal behavior (Choe et al, 2012; Kaplan et al, 2012; Noguez et al, 2012; Roder et al, 2019), however, the composition and function of ascarosides in EPN is limited, and the function of daf-22 is unknown, due to the lack of genetic tools. As a proof of concept, I performed in vivo dauer (IJ) entry assay by infecting Galleria insect larvae (waxworm) with S. hermaphroditum IJs of wild type and Sh-daf-22 (mc0006) .…”

“…As a proof of concept, I performed in vivo dauer (IJ) entry assay by infecting Galleria insect larvae (waxworm) with S. hermaphroditum IJs of wild type and Sh-daf-22 (mc0006) . In a normal life cycle, entomopathogenic nematodes reproduce in the infected insects and emerge as IJs in response to environmental cues including pheromones (Roder et al, 2019). I collected and examined the population of nematodes that emerged from the Galleria insects (Fig.…”