UMass Chan Medical School Faculty Publications

UMMS Affiliation

UMass Metabolic Network; Department of Biochemistry and Molecular Pharmacology

Publication Date


Document Type



Biochemical Phenomena, Metabolism, and Nutrition | Cellular and Molecular Physiology | Developmental Biology | Genetic Phenomena | Genetics and Genomics


Bleaching gravid C. elegans followed by a short period of starvation of the L1 larvae is a routine method performed by worm researchers for generating synchronous populations for experiments. During the process of investigating dietary effects on gene regulation in L1 stage worms by single-worm RNA-Seq, we found that the density of resuspended L1 larvae affects expression of many mRNAs. Specifically, a number of genes related to metabolism and signalling are highly expressed in worms arrested at low density, but are repressed at higher arrest densities. We generated a GFP reporter strain based on one of the most density-dependent genes in our dataset - lips-15 - and confirmed that this reporter was expressed specifically in worms arrested at relatively low density. Finally, we show that conditioned media from high density L1 cultures was able to downregulate lips-15 even in L1 animals arrested at low density, and experiments using daf-22 mutant animals demonstrated that this effect is not mediated by the ascaroside family of signalling pheromones. Together, our data implicate a soluble signalling molecule in density sensing by L1 stage C. elegans, and provide guidance for design of experiments focused on early developmental gene regulation.


chemical signaling, density effects, development, gene expression

Rights and Permissions

Copyright © 2018. G3 applies a Creative Commons Attribution License ( to all its published material, per

DOI of Published Version



G3 (Bethesda). 2018 Mar 30. pii: g3.118.200056. doi: 10.1534/g3.118.200056. Link to article on publisher's site

Related Resources

Link to Article in PubMed

Journal/Book/Conference Title

G3 (Bethesda, Md.)

PubMed ID


Creative Commons License

Creative Commons Attribution 4.0 License
This work is licensed under a Creative Commons Attribution 4.0 License.