Related Experiment Videos
Macrophage migration inhibitory factor (mif) transcription is significantly elevated in Caenorhabditis elegans dauer
A L Marson1, D E Tarr, A L Scott
1The W. Harry Feinstone Department of Molecular Microbiology and Immunology, The Johns Hopkins University, Bloomberg School of Public Health, 615 N. Wolfe Street, Baltimore, MD 21205, USA.
Abstract:
Macrophage migration inhibitory factor (MIF) from vertebrate species is a molecule that exerts a wide-range of effects in inflammatory responses, cell activation and cell differentiation. Several species of parasitic nematodes have been shown to express genes encoding orthologues of the mammalian MIF that appear to play a key role in immune evasion by modifying the activity of host cells. In addition, MIF accumulates in nematode somatic cells where its role has not yet been defined. In order to identify the role that MIF plays in the cell biology of nematodes, we have characterized the members of the mif gene family in the free-living species Caenorhabditis elegans. Unlike the single mif gene found in humans and mice, C. elegans expresses four distinct mif genes: Ce-mif-1, Ce-mif-2, Ce-mif-3 and Ce-mif-4. The Ce-MIF proteins are between 15-30% identical to each other, 34-38% identical to the MIFs from the parasitic nematode Brugia malayi, and 22-35% identical to mammalian MIFs. The transcription of Ce-mif-2 and Ce-mif-3, but not Ce-mif-1, was upregulated >100-fold compared to L2 levels when the worms entered the dauer stage. The transcription levels of Ce-mif-2 and Ce-mif-3 fell to near baseline a few hours after exit from dauer. Ce-MIF/GFP transgenic animals and immunostaining were used to demonstrate that the main sites of MIF production are in the hypodermis, body wall muscles and in the nuclei of developing embryos. The results suggest a role for C. elegans MIF in cellular maintenance during periods of adverse conditions that lead to developmental arrest.
Insights
The study identified four Macrophage Migration Inhibitory Factor (MIF) genes in C. elegans. Two of these genes are significantly upregulated during the dauer stage, suggesting a role in cellular maintenance during stress.
Area of Science:
- Molecular Biology
- Developmental Biology
- Nematology
Background:
- Macrophage Migration Inhibitory Factor (MIF) is crucial in vertebrate inflammatory responses.
- Parasitic nematodes utilize MIF orthologs for immune evasion.
- The function of MIF in nematode somatic cells remains largely undefined.
Purpose of the Study:
- To characterize the mif gene family in the free-living nematode Caenorhabditis elegans.
- To investigate the expression patterns and cellular localization of C. elegans MIF proteins.
- To elucidate the role of MIF in nematode cell biology, particularly during stress conditions.
Main Methods:
- Gene family characterization of mif genes in C. elegans.
- Quantitative analysis of Ce-mif gene transcription during different life stages.
- Localization studies using Ce-MIF/GFP transgenic animals and immunostaining.
Main Results:
- C. elegans possesses four distinct mif genes (Ce-mif-1, Ce-mif-2, Ce-mif-3, Ce-mif-4).
- Transcription of Ce-mif-2 and Ce-mif-3 dramatically increases during the dauer developmental arrest stage.
- MIF proteins are primarily produced in hypodermis, body wall muscles, and embryonic nuclei.
Conclusions:
- C. elegans MIF proteins exhibit sequence homology to both mammalian and parasitic nematode MIFs.
- Ce-mif-2 and Ce-mif-3 expression is tightly regulated by developmental stage, particularly dauer formation.
- Results suggest a role for C. elegans MIF in cellular maintenance and survival during adverse environmental conditions.