Cis-regulatory evolution shapes dehydration response in a desert-adapted house mouse

Area of Science:

• Genomics and Evolutionary Biology
• Environmental Adaptation
• Physiological Genetics

Background:

• Deserts present extreme environmental challenges, driving local adaptation in species like the house mouse (Mus musculus domesticus).
• Sonoran Desert house mice exhibit phenotypic adaptations to water scarcity, suggesting underlying genetic changes.
• Understanding the genetic basis of adaptation to dehydration is crucial for studying survival in extreme environments.

Purpose of the Study:

• To investigate the genetic mechanisms of adaptation to water deprivation in house mice.
• To compare gene expression responses to dehydration between desert and non-desert house mouse subspecies.
• To identify cis-regulatory differences contributing to transcriptional divergence in response to water stress.

Main Methods:

• Comparative gene expression analysis of desert and non-desert house mice (M. m. musculus) and their hybrids under dehydration stress.
• Surveying allele-specific expression in intersubspecific hybrids to detect cis-regulatory differences.
• Tissue-specific analysis (hypothalamus, liver, kidney) of transcriptional responses.

Main Results:

• Desert and non-desert mice show significantly divergent gene expression patterns in response to water deprivation.
• Cis-regulatory differences, particularly cis-by-environment interactions, drive these divergent transcriptional responses.
• These cis-regulatory changes are tissue-specific and impact genes involved in the arachidonic acid pathway and lipid metabolism.

Conclusions:

• Context-dependent cis-regulatory evolution is a key factor in the rapid adaptation of house mice to desert environments.
• Tissue-specific regulatory changes facilitate adaptation to extreme conditions like water scarcity.
• Identified candidate genes and pathways provide insights into the genetic basis of adaptation to arid environments.