# Signals and circuits that regulate developmental timing

> **NIH NIH R01** · NORTHWESTERN UNIVERSITY · 2024 · $413,690

## Abstract

PROJECT SUMMARY
Deviations from the order or timing of developmental events often result in abnormalities. Understanding how
such well-regulated process can remain plastic, that is, be able to flexibly change depending on the environment
is an important question. Social signals exchanged by members of the same species constitute a prominent
class of environmental effects that can alter development. A representative example of such social effects is the
observation that female mammals attain sexual maturity faster if exposed to adult males. We found that males
of the classic model species C. elegans also excrete signals that hasten sexual maturation of the opposite sex.
Our preliminary studies revealed the following features of this process. (A) Developmental acceleration occurs
late indicating that the onset of adulthood is specifically hastened. (B) Developmental acceleration involves faster
progression of events in multiple cell lineages suggesting that it is systemic. (C) Developmental acceleration is
accompanied by appropriately accelerated organismal growth. (D) Males excrete small-molecule signals that
belong to two distinct chemical classes. Either molecule alone can accelerate development implying redundancy.
(E) Sensory neurons are required for acceleration, suggesting that they may detect the acceleration-inducing
pheromones. (F) In addition to causing accelerated growth and development, these pheromones also alter
behaviors involved in obtaining food, presumably to provide additional resources to sustain faster development.
These findings serve as a foundation for our research program that will pursue the following goals. (1) Taking
advantage of the unique strengths of C. elegans as a model system, delineate neuronal circuits required to
accelerate development in response to pheromones. These circuits are expected to consist of multiple neurons
that signal to each other via specific transmitters and receptors. Major impact of this work will be the identification
of ways in which the nervous system non-autonomously regulates organismal growth and development. The
promise of this approach is the ability to alter the rate of development and growth by opto- and chemogenetic
manipulation of specific neurons. (2) To identify components of signaling pathways that are required for
acceleration, particularly those that coordinate development and growth. (3) An unexpected theme emerging
from our work is that regulation of developmental events and appropriate behaviors are coupled because both
rely on the same neuronal circuits. We are using machine-vision to simultaneously monitor behavior,
development, and growth to test this hypothesis. Our quantitative and innovative approach bridges concepts and
tools from several distinct fields. We aim to provide an undertesting of developmental processes enriched by
considerations of social interactions that are emerging as a major contributor to inter-individual developmental
variation, including as poss...

## Key facts

- **NIH application ID:** 10856315
- **Project number:** 1R01GM153791-01
- **Recipient organization:** NORTHWESTERN UNIVERSITY
- **Principal Investigator:** Ilya Ruvinsky
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $413,690
- **Award type:** 1
- **Project period:** 2024-07-15 → 2028-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10856315

## Citation

> US National Institutes of Health, RePORTER application 10856315, Signals and circuits that regulate developmental timing (1R01GM153791-01). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10856315. Licensed CC0.

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