Quantitative genetics of microbiome-mediated traits.

Area of Science:

• Evolutionary Biology
• Microbiology
• Quantitative Genetics

Background:

• Multicellular organisms harbor complex microbial communities (microbiomes) that can influence host fitness.
• The evolutionary impact of host-microbiome interactions is not fully understood due to a lack of integrated theoretical frameworks.
• Phenotypic variation arises from both host genetics and microbial associations.

Purpose of the Study:

• To extend quantitative genetic theory to incorporate host-associated microbes as a source of phenotypic variation.
• To develop a framework for predicting microbiome-mediated host responses to selection.
• To generalize heritability concepts to include microbial contributions.

Main Methods:

• Developed a quantitative genetic framework incorporating host alleles and microbiome components.
• Introduced methods to partition microbiomes for predicting selection responses.
• Applied the framework to a simulation model of microbiome inheritance.

Main Results:

• Host-associated microbes, alongside host genetics, explain quantitative trait variation.
• Microbiome-mediated selection responses can occur through vertical and non-vertical transmission modes.
• The contribution of non-vertical microbial transmission to host evolution depends on host life history.

Conclusions:

• This work provides a foundational framework for integrating microbiome effects into evolutionary biology.
• It enables a more comprehensive understanding of host variation and adaptation in the context of their associated microbes.
• Future research can build upon this framework to explore diverse host-microbiome systems.