Related Experiment Video
Updated: Aug 11, 2026
10:46
Novel Metrics to Characterize Embryonic Elongation of the Nematode Caenorhabditis elegans
Published on: March 28, 2016
The evolution of tissue migration by parasitic nematode larvae
1Department of Ecology/Zoology, University of Tromsø, Norway.
Parasitology
|September 1, 1995
Summary
Nematode larvae migration through mammalian tissues, though risky, offers a growth advantage. This faster development leads to larger worms, increasing reproductive success and explaining the evolutionary persistence of this behavior.
Area of Science:
- Parasitology
- Evolutionary Biology
- Animal Physiology
Background:
- Nematode larval migration through mammalian tissues causes pathology, but its evolutionary drivers remain unclear.
- The extensive migrations of some nematode larvae, like Ascaris and Strongylus, appear paradoxical as they begin and end in the same location.
- While tissue migration is often considered a developmental necessity, it incurs significant biochemical and morphological costs and risks for the larvae.
Purpose of the Study:
- To investigate the evolutionary advantages of nematode larval tissue migration in mammalian hosts.
- To test the hypothesis that tissue migration is a selectively advantageous life-history strategy.
- To explore the relationship between juvenile habitat and adult nematode size.
Main Methods:
- Comparative analysis of nematode taxa with and without tissue migratory phases.
- Statistical assessment of the association between juvenile habitat and adult size, controlling for confounding factors.
- Examination of growth rates and time to reproduction in relation to migratory behavior.
Main Results:
- Nematode taxa that undergo tissue migration during development are, on average, significantly larger than their relatives developing solely in the gastrointestinal tract.
- This size increase is independent of adult habitat, life-cycle complexity, host characteristics, or generation time.
- Worms with a tissue phase exhibit faster growth rates, reaching reproductive maturity in the same timeframe as non-migratory counterparts.
Conclusions:
- Nematode larval tissue migration is a selectively advantageous strategy, providing a faster growth rate.
- The increased adult size resulting from faster growth enhances fecundity, offering a significant evolutionary benefit.
- This provides a compelling explanation for the maintenance of complex migratory behaviors in parasitic nematodes, analogous to pre-spawning migrations in fish.
Related Concept Videos
01:56Gastrulation
Gastrulation establishes the three primary tissues of an embryo: the ectoderm, mesoderm, and endoderm. This developmental process relies on a series of intricate cellular movements, which in humans transforms a flat, “bilaminar disc” composed of two cell sheets into a three-tiered structure. In the resulting embryo, the endoderm serves as the bottom layer, and stacked directly above it is the intermediate mesoderm, and then the uppermost ectoderm. Respectively, these tissue strata will form...
01:09Cell Migration
Cell migration, the process by which cells move from one location to another, is essential for the proper development and viability of organisms throughout their life. When cells are not able to migrate properly to their ordained locations, various disorders may occur. For example, disruption in cell migration causes chronic inflammatory diseases such as arthritis.
01:19Cell Migration
Cell migration is a process by which the cells move from one location to another, playing an essential role in embryological development, repair and regeneration, immune response, and metastasis. Cells migrate in response to chemical or mechanical signals generated by specific organs or tissues. The overall mechanism includes three steps - polarization, protrusion, and release. Polarization involves the formation of a distinct cell front and rear, which determines the direction of movement.
01:35Cancer Cell Migration through Invadopodia
Invadosome is a broad category of cell surface structures with proteolytic activity that degrades the extracellular matrix (ECM). Invadosomes are present in normal cell types, including macrophages, endothelial cells, and neurons, as well as tumor cells. Although the macrophage podosomes and tumor cell invadopodia are classified as invadosomes, they have different structures, molecular pathways, and functions. Podosomes are short structures that last for a few minutes. However, invadopodia can...
01:21Chemotaxis and Direction of Cell Migration
Cells can detect chemical cues in their environment and reorganize the cytoskeleton to migrate toward them or away from them. This directional migration, called chemotaxis, is essential during embryogenesis and development, immune response, tissue repair and regeneration, and reproduction. These chemical cues can either attract or repel the cell's movement. For example, axon development is determined by a combination of chemoattractants and chemorepellents that direct the growing axon towards...
01:32Cytoskeletal Coordination in Cell Migration
A migrating cell changes its shape during the cyclic events of attachment and detachment from the substratum and repositions the cell organelles correspondingly. These complex events are orchestrated by the dynamic cytoskeletal network comprising actin filaments, intermediate filaments, and microtubules. Cytoskeletal crosstalk — the direct and indirect communication between the different components — is crucial for this coordination. Direct communication involves various linker proteins that...