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Quantitative Measurement of the Immune Response and Sleep in Drosophila
Published on: December 4, 2012
Genotype and gene expression associations with immune function in Drosophila
Timothy B Sackton1, Brian P Lazzaro, Andrew G Clark
1Field of Ecology and Evolutionary Biology, Cornell University, Ithaca, New York, United States of America. tbs7@cornell.edu
Plos Genetics
|January 13, 2010
Summary
Genetic variation in Drosophila melanogaster immune genes influences bacterial load. Polymorphisms in pathogen recognition genes significantly impact immunity, demonstrating how early genetic changes amplify through the immune cascade.
Area of Science:
- Immunology
- Genetics
- Drosophila melanogaster research
Background:
- Natural populations of Drosophila melanogaster exhibit significant genetic variation in immune function.
- Intermediate immune measures, like immune-related gene transcriptional activity, have not been fully explored as mediators of immunity variation.
Purpose of the Study:
- To investigate the association between genetic variation, bacterial load, and immune gene transcriptional dynamics in Drosophila melanogaster.
- To identify specific immune genes and genetic markers linked to phenotypic variation in immunity.
Main Methods:
- Infection of 94 third-chromosome substitution lines of D. melanogaster with four bacterial species.
- Measurement of bacterial load and transcriptional levels of 329 immune-related genes post-infection.
- Genotyping of substitution lines at 137 polymorphic markers across 25 genes.
Main Results:
- Genetic polymorphisms in pathogen recognition genes (PGRP-LC, GNBP1, GNBP2) strongly correlate with bacterial load variation.
- Transcriptional induction of effector proteins predicts bacterial load after E. faecalis infection.
- A marker upstream of PGRP-SD associates with variation in both bacterial load and transcriptional induction.
Conclusions:
- Polymorphisms in genes at the beginning of the immune signaling cascade can disproportionately affect organismal phenotype.
- Genetic variation in pathogen recognition genes plays a crucial role in modulating Drosophila melanogaster's immune response.
- Amplification of effects through the immune cascade explains the significant impact of upstream genetic variations.
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