Work

Steroid hormone pathways coordinate developmental diapause and olfactory remodeling in Pristionchus pacificus

Year: 2021

Type: article

Abstract: Developmental and behavioral plasticity allow animals to prioritize alternative genetic programs during fluctuating environments. Behavioral remodeling may be acute in animals that interact with host organisms, since reproductive adults and the developmentally arrested larvae often have different ethological needs for chemical stimuli. To understand the genes that coordinate the development and host-seeking behavior, we used the entomophilic nematode Pristionchus pacificus to characterize dauer-constitutive mutants (Daf-c) that inappropriately enter developmental diapause to become dauer larvae. We found two Daf-c loci with dauer-constitutive and cuticle exsheathment phenotypes that can be rescued by the feeding of Δ7-dafachronic acid, and that are dependent on the conserved canonical steroid hormone receptor Ppa-DAF-12. Specifically at one locus, deletions in the sole hydroxysteroid dehydrogenase (HSD) in P. pacificus resulted in Daf-c phenotypes. Ppa-hsd-2 is expressed in the canal-associated neurons (CANs) and excretory cells whose homologous cells in Caenorhabditis elegans are not known to be involved in the dauer decision. While in wildtype only dauer larvae are attracted to host odors, hsd-2 mutant adults show enhanced attraction to the host beetle pheromone, along with ectopic activation of a marker for putative olfactory neurons, Ppa-odr-3. Surprisingly, this enhanced odor attraction acts independently of the Δ7-DA/DAF-12 module, suggesting that Ppa-HSD-2 may be responsible for several steroid hormone products involved in coordinating the dauer decision and host-seeking behavior in P. pacificus.

Source: Genetics

DOI: 10.1093/genetics/iyab071

Authors: Heather R Carstensen, Reinard M Villalon, Navonil Banerjee, Elissa A Hallem, Ray L Hong

Institutions: California State University, Northridge, University of California, Los Angeles

Language: English

Topic: Nematode management and characterization studies

Subfield: Plant Science

Field: Agricultural and Biological Sciences

Domain: Life Sciences

Open Access status: bronze

Funders: National Institutes of Health, National Institute on Deafness and Other Communication Disorders, National Institute of General Medical Sciences, National Institute of Allergy and Infectious Diseases