Thermal conditioning of quail embryos has transgenerational and reversible long‑term effects

Background In the current context of global warming,thermal manipulation of avian embryos has received increasing attention as a strategy to promote heat tolerance in avian species by simply increasing the egg incubation temperature.However,because of their likely epigenetic origin,thermal manipulation effects may last more than one generation with consequences for the poultry industry.In this work,a multigenerational and transgenerational analysis of thermal manipulation during embryogenesis was performed to uncover the long-term effects of such procedure.Results Thermal manipulation repeated during 4 generations had an effect on hatchability,body weight,and weight of eggs laid in Japanese quails,with some effects increasing in importance over generations.Moreover,the effects on body weight and egg weight could be transmitted transgenerationally,suggesting non-genetic inheritance mechanisms.This hypothesis is reinforced by the observed reversion of the effect on growth after five unexposed generations.Interestingly,a beneficial effect of thermal manipulation on heat tolerance was observed a few days after hatching,but this effect was not transgenerational.Conclusions Our multigenerational study showed that thermal conditioning of quail embryos has a beneficial effect on post-hatch heat tolerance hampered by transgenerational but reversible defects on growth.Assuming that no genetic variability underlies these changes,this study provides the first demonstration of epigenetic inheritance of traits induced by environmental temperature modification associated with long-term impacts in an avian species.

表观遗传学与表型变异

鸡的基因组是农业领域首批被测序和注释（尽管不完全）的动物基因组之一,其特点是基因组相对较小、存在表观遗传属性迥异的微型和大型染色体以及哺乳动物不同的性别决定方式。