Article thumbnail
Location of Repository

The Oogenic Germline Starvation Response in C. elegans

By Hannah S. Seidel and Judith Kimble

Abstract

Many animals alter their reproductive strategies in response to environmental stress. Here we have investigated how L4 hermaphrodites of Caenorhabditis elegans respond to starvation. To induce starvation, we removed food at 2 h intervals from very early- to very late-stage L4 animals. The starved L4s molted into adulthood, initiated oogenesis, and began producing embryos; however, all three processes were severely delayed, and embryo viability was reduced. Most animals died via ‘bagging,’ because egg-laying was inhibited, and embryos hatched in utero, consuming their parent hermaphrodites from within. Some animals, however, avoided bagging and survived long term. Long-term survival did not rely on embryonic arrest but instead upon the failure of some animals to produce viable progeny during starvation. Regardless of the bagging fate, starved animals showed two major changes in germline morphology: All oogenic germlines were dramatically reduced in size, and these germlines formed only a single oocyte at a time, separated from the remainder of the germline by a tight constriction. Both changes in germline morphology were reversible: Upon re-feeding, the shrunken germlines regenerated, and multiple oocytes formed concurrently. The capacity for germline regeneration upon re-feeding was not limited to the small subset of animals that normally survive starvation: When bagging was prevented ectopically by par-2 RNAi, virtually all germlines still regenerated. In addition, germline shrinkage strongly correlated with oogenesis, suggesting that during starvation, germline shrinkage may provide material for oocyte production. Finally, germline shrinkage and regeneration did not depend upon crowding. Our study confirms previous findings that starvation uncouples germ cell proliferation from germline stem cell maintenance. Our study also suggests that when nutrients are limited, hermaphrodites scavenge material from their germlines to reproduce. We discuss our findings in light of the recently proposed state of dormancy, termed Adult Reproductive Diapause

Topics: Research Article
Publisher: Public Library of Science
OAI identifier: oai:pubmedcentral.nih.gov:3229504
Provided by: PubMed Central

Suggested articles

Citations

  1. (2006). DAF-16/FOXO regulates transcription of cki1/Cip/Kip and repression of lin-4 during C. elegans L1 arrest.
  2. (1998). Developmental regulation of a cyclindependent kinase inhibitor controls postembryonic cell cycle progression in Caenorhabditis elegans.
  3. (2000). Effect of a neuropeptide gene on behavioral states in Caenorhabditis elegans egg-laying.
  4. (2000). egl-4 acts through a transforming growth factor-beta/SMAD pathway in Caenorhabditis elegans to regulate multiple neuronal circuits in response to sensory cues.
  5. (2004). Facultative vivipary is a life-history trait in Caenorhabditis elegans.
  6. (1987). glp-1 is required in the germ line for regulation of the decision between mitosis and meiosis in C.
  7. (2006). Maintenance of C.
  8. (2009). MSP and GLP-1/Notch signaling coordinately regulate actomyosin-dependent cytoplasmic streaming and oocyte growth in C.
  9. (1999). On the control of oocyte meiotic maturation and ovulation in Caenorhabditis elegans.
  10. (2003). PAR proteins regulate microtubule dynamics at the cell cortex in C.
  11. (2003). Plasticity in butterfly egg size: Why larger offspring at lower temperatures?
  12. (2002). Regulation of diapause.
  13. (2001). Slow aging during insect reproductive diapause: why butterflies, grasshoppers and flies are like worms.
  14. (2009). Starvation protects germline stem cells and extends reproductive longevity in
  15. (2006). Stress-induced germ cell apoptosis by a p53 independent pathway in Caenorhabditis elegans.
  16. (2003). Systematic functional analysis of the Caenorhabditis elegans genome using RNAi.
  17. (1975). The dauerlarva, a post-embryonic developmental variant of the nematode Caenorhabditis elegans.
  18. (1999). The evolutionary genetics of an adaptive maternal effect: Egg size plasticity in a seed beetle.
  19. (2003). Why Caenorhabditis elegans adults sacrifice their bodies to progeny.

To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.