Genomic imprinting and conflict-induced decanalization.

Area of Science:

• Genetics
• Evolutionary Biology
• Developmental Biology

Background:

• Genomic imprinting involves allele expression dependent on parental origin.
• Parental conflict at imprinted loci drives an evolutionary "arms race" for expression levels.

Purpose of the Study:

• To model the consequences of escalating expression at maternally and paternally expressed imprinted loci.
• To investigate the phenomenon of "conflict-induced decanalization" and its impact on population fitness and disease.

Main Methods:

• Theoretical modeling of gene expression dynamics.
• Analysis of selection pressures on imprinted loci and gene expression modifiers.
• Derivation of population-level consequences of genetic conflict.

Main Results:

• Escalation in expression at imprinted loci increases variance in gene expression and phenotypic variance.
• Selection favoring modifiers that canalize gene expression leads to further escalation and net decanalization.
• This feedback loop reduces population mean fitness.

Conclusions:

• Conflict-induced decanalization, driven by genomic imprinting, increases phenotypic variance.
• This process may contribute to the high incidence of diseases including preterm birth, schizophrenia, and autism.
• Understanding this genetic conflict is crucial for explaining disease etiology and evolutionary dynamics.