Caenorhabditis elegans

Definition

Caenorhabditis elegans is a small, transparent nematode (roundworm) that is widely used as a model organism in developmental biology and genetics. This tiny worm, about 1 mm in length, has a simple body plan and a well-mapped genome, making it an invaluable tool for studying mechanisms of cell fate determination and understanding the origins and evolution of developmental processes.

5 Must Know Facts For Your Next Test

1. C. elegans has a fixed number of cells (approximately 1,000), which makes it easier to study the exact lineage and fate of each cell during development.
2. This organism undergoes distinct developmental stages: embryo, larval stages (L1 to L4), and adult, allowing for the observation of cell differentiation and fate determination.
3. C. elegans is particularly known for studies involving RNA interference (RNAi), which has provided insights into gene function and regulation.
4. Research on C. elegans has revealed key insights into conserved developmental pathways that are relevant to more complex organisms, including humans.
5. The simplicity of its nervous system, consisting of only 302 neurons, makes C. elegans an excellent model for studying neural development and function.

Review Questions

• How does the fixed cell number in C. elegans facilitate the study of cell fate determination?
  • The fixed number of cells in C. elegans, approximately 1,000, allows researchers to trace the lineage and fate of each individual cell throughout development. This unique feature enables detailed studies on how specific cells differentiate and what factors influence their fates. By understanding these processes in such a simple organism, scientists can draw parallels to more complex organisms where the mechanisms may be similar but more difficult to dissect.
• Discuss the role of C. elegans in advancing our understanding of apoptosis and its implications in developmental biology.
  • C. elegans has been crucial in elucidating the genetic pathways governing apoptosis, which is essential for proper development. Research has shown that specific genes are involved in triggering programmed cell death, highlighting how apoptosis contributes to shaping tissues and organs during growth. The findings from C. elegans have broad implications, as the core mechanisms of apoptosis are conserved across many species, including humans.
• Evaluate how studies on C. elegans contribute to our understanding of the evolution of developmental processes across different organisms.
  • Studies on C. elegans provide key insights into conserved developmental processes that have persisted throughout evolution, highlighting similarities among diverse species. By mapping its simple developmental pathways and genetic networks, researchers can identify fundamental principles that govern development in more complex organisms. This comparative approach enhances our understanding of evolutionary biology by illustrating how certain traits have evolved while retaining essential functions across various lineages.

Related terms

Model Organism: A species that is extensively studied to understand particular biological phenomena, often because it shares many characteristics with other organisms.

Apoptosis: The process of programmed cell death that occurs in multicellular organisms, playing a crucial role in development and maintaining tissue homeostasis.

Cell Lineage: The history of cell divisions and differentiation from a single cell to its descendant cells, which helps to understand the development of tissues and organs.