Sexually antagonistic epigenetic marks that canalize sexually dimorphic development

Area of Science:

• Genetics
• Developmental Biology
• Epigenetics

Background:

• Sexual dimorphism arises from sex-specific gene expression, influenced by XX/XY karyotypes and testosterone (T) in mammals.
• Environmental factors can disrupt sexual development, but epigenetic marks (epimarks) canalize ontogeny.
• Epimarks can increase XY embryo sensitivity to T and decrease XX embryo sensitivity.

Purpose of the Study:

• To synthesize evidence for canalizing epimarks during early ontogeny.
• To describe evidence of epimark carryover across generations.
• To explore the consequences of sexually antagonistic epimarks (SA-epimarks).

Main Methods:

• Literature review and synthesis of existing evidence.
• Analysis of epigenetic mechanisms in sexual development.
• Integration of data on epimark inheritance and effects.

Main Results:

• Canalizing epimarks are produced during early development, influencing sex-specific gene expression.
• Epimarks can persist across generations, leading to mosaicism and gonad-trait discordances.
• SA-epimarks benefit the carrier but harm opposite-sex offspring.

Conclusions:

• Epimarks play a crucial role in canalizing sexual development and influencing gene expression.
• Transgenerational epimark inheritance can lead to sexually antagonistic effects and phenotypic variation.
• SA-epimarks have implications for sexual selection and medically relevant gonad-trait discordances.