Interesting and important findings (from 2018, but new to me!) 🐭⬇️
You'd expect phenotypic variance to be lower in inbred strains cuz genetic variance (Vg) = zero.
But because they are inbred (homozygous at all alleles) the ability of cellular systems to buffer noise or environmental fluctuations may be much lower
This means that the non-genetic sources of variance (here called Ve, but not necessaarily "environmental") may be much higher:
Homozygosity is BAD! (Not just cuz of specific deleterious recessive effects, but generally for the robustness of the whole system)
This has parallels in the slightly increased variance of males > females for all kinds of traits, most likely due to hemizygosity (having only one copy) of the X chromosome
Making the entire genome homozygous should have correspondingly larger effects on variance

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