Data from: Air-borne genotype by genotype indirect genetic effects are substantial in the filamentous fungus Aspergillus nidulans

Genotype by genotype indirect genetic effects (G × G IGEs) occur when the
phenotype of an individual is influenced by an interaction between its own
genotype and those of neighbour individuals. Little is known regarding the
relative importance of G × G IGEs compared with other forms of direct and
indirect genetic effects. We quantified the relative importance of IGEs in
the filamentous fungus Aspergillus nidulans, a species in which IGEs are
likely to be important as air-borne social interactions are known to
affect growth. We used a collection of distantly related wild isolates,
lab strains and a set of closely related mutation accumulation lines to
estimate the contribution of direct and indirect genetic effects on
mycelium growth rate, a key fitness component. We found that indirect
genetic effects were dominated by G × G IGEs that occurred primarily
between a focal genotype and its immediate neighbour within a vertical
stack, and these accounted for 11% of phenotypic variation. These results
indicate that G × G IGEs may be substantial, at least in some systems, and
that the evolutionary importance of these interactions may be
underappreciated, especially in microbes. We advocate for a wider use of
the IGE framework in both applied (for example, choice of varietal
mixtures in plant breeding) and evolutionary genetics (kin selection/kin
competition studies).