Environmental change drives accelerated adaptation through stimulated copy number variation

Area of Science:

• Genetics
• Molecular Biology
• Epigenetics

Background:

• Copy number variation (CNV) is common in eukaryotic genomes and linked to human diseases like cancer.
• Transcription can disrupt DNA replication, increasing mutation rates at active genes.
• The role of environmental stimuli in directing genetic changes like CNV is not fully understood.

Purpose of the Study:

• To investigate if inducible promoters can stimulate CNV for reproducible, environment-specific genetic changes.
• To propose and validate a mechanism for environmentally-stimulated CNV.
• To explore the regulation of CNV by promoter activity and histone acetylation.

Main Methods:

• Analyzing individual yeast cells exposed to varying copper concentrations.
• Quantifying copy number variation (CNV) of the CUP1 gene.
• Investigating the role of histone H3 lysine 56 acetylation (H3K56ac) in CNV regulation.

Main Results:

• Environmental copper directly stimulates CNV of the CUP1 gene in budding yeast.
• CNV accelerates the adaptation to copper-rich environments by creating beneficial alleles.
• Promoter activity and H3K56ac regulate CNV, with H3K56ac being crucial for CUP1 CNV and copper adaptation.

Conclusions:

• Environmentally stimulated CNV is a controllable pathway for organismal adaptation.
• Transcription-associated DNA damage can be directed to specific loci by environmental cues.
• Histone acetylation, specifically H3K56ac, plays a key role in regulating environmentally stimulated CNV.