Complementary genomic and epigenomic adaptation to environmental heterogeneity

Area of Science:

• Evolutionary biology
• Marine ecology
• Genetics and epigenetics

Background:

• Adaptation is traditionally linked to genetic variation, but epigenetic variation also plays a role.
• The interplay between genetic and epigenetic mechanisms in adaptation, especially under environmental change, requires further investigation.

Purpose of the Study:

• To investigate the genetic and epigenetic mechanisms underlying adaptation in Botryllus schlosseri populations.
• To determine the relative contributions of genetic and epigenetic variation to population persistence and invasion success in heterogeneous environments.

Main Methods:

• Screening of genomes and epigenomes from nine global populations of Botryllus schlosseri.
• Analysis of population differentiation at both genetic and epigenetic levels.
• Correlation of genetic and epigenetic patterns with local environmental variables, particularly sea surface temperature.

Main Results:

• Significant genetic and epigenetic population differentiation was observed.
• Environmental variables, especially minimum annual sea surface temperature, strongly influenced both genetic and epigenetic structures.
• Distinct patterns of population structure between genetic and epigenetic variation suggest potential epigenetic autonomy.
• Shared and specific genes/pathways were identified for both genetic and epigenetic loci linked to environmental factors.

Conclusions:

• Both genetic and epigenetic variations contribute to environmental adaptation in Botryllus schlosseri, with potentially complementary and independent roles.
• These combined mechanisms likely enhance population persistence under environmental change and support successful invasions.
• Epigenetic variation may offer an autonomous mechanism for adaptation alongside genetic variation.