Shared Genomic Regions Underlie Natural Variation in Diverse Toxin Responses

Area of Science:

• Genetics
• Toxicology
• Developmental Biology

Background:

• Phenotypic complexity arises from environmental factors and multiple genetic loci, often interacting.
• In metazoans, many heritable components of phenotypic variation remain undetected, termed 'missing heritability'.
• Detecting loci requires high replication and precise measurements to overcome statistical power limitations.

Purpose of the Study:

• To identify genetic loci underlying responses to diverse toxins in a metazoan model.
• To dissect the relative contributions of additive and interactive genetic variance components.
• To identify potential common genetic factors influencing responses across multiple toxin classes.

Main Methods:

• Utilized a panel of 296 recombinant inbred advanced intercross lines of *Caenorhabditis elegans*.
• Employed a high-throughput fitness assay to measure responses to 16 different toxins.
• Applied linkage mapping to identify quantitative trait loci (QTL) and generated near-isogenic lines for validation.

Main Results:

• Identified 82 QTL associated with variation in responses to heavy metals, chemotherapeutics, pesticides, and neuropharmaceuticals.
• Predicted the relative contributions of additive loci and genetic interactions to phenotypic variation.
• Discovered three genomic regions (QTL hotspots) influencing responses to multiple toxin classes, suggesting shared genetic underpinnings.

Conclusions:

• Additive and interactive genetic loci significantly contribute to toxin-response variation in *C. elegans*.
• QTL hotspots represent potential common genetic factors involved in detoxification or response pathways.
• This study provides a framework for dissecting missing heritability in metazoan models.