Genetic conflicts, multiple paternity and the evolution of genomic imprinting

Area of Science:

• Evolutionary genetics
• Developmental biology

Background:

• Genomic imprinting, the differential expression of alleles based on parental origin, plays a crucial role in mammalian development.
• Existing models often predict specific imprinting patterns (e.g., paternal imprinting of growth inhibitors) driven by genetic conflicts.

Purpose of the Study:

• To investigate the evolution of genomic imprinting using novel diallelic genetic conflict models.
• To examine the influence of mating systems (monogamy vs. bigamy) and multiple paternity on imprinting evolution.

Main Methods:

• Development of nine diallelic genetic conflict models with one imprintable and one non-imprintable allele.
• Analysis of maternal and paternal imprinting dynamics under varying degrees of female mating fidelity.

Main Results:

• Genetic conflicts do not necessitate specific imprinting patterns; maternal and paternal imprinting dynamics can be identical under strict monogamy.
• Multiple paternity is not essential for imprinting evolution and has no effect on maternal imprinting dynamics.
• Multiple paternity favors paternal imprinting of growth inhibitors and hinders maternal imprinting of growth enhancers.
• Stable polymorphism of imprinting status and potential decreases in mean fitness over time were observed, outcomes not predicted by prior models.

Conclusions:

• The evolution of genomic imprinting is more complex than previously modeled, with mating systems significantly influencing imprinting patterns.
• Novel predictions regarding imprinting dynamics and their potential fitness consequences are presented.