A transcriptomic investigation of heat-induced transgenerational plasticity in beetles

Abstract

AbstractIn response to environmental stressors, parents can shape the developmental outcomes of their offspring by contributing non-genetic but heritable factors. The transmission of such factors can potentially allow offspring, from the beginning of their lives, to express phenotypes that match their anticipated environments. In this study, I ask whether enhanced growth in larvae of Onthophagus taurus (the bull-headed dung beetle) is modified by parental exposure to heat or by exposure of the offspring to heat during early life. I find that, irrespective of the early environment of the offspring, individuals produced by parents exposed to heat grow larger. Furthermore, taking a transcriptomic approach, I find that ecdysone signalling might mediate the transgenerational effect and that increased insulin signalling or reduced production of heat shock proteins might be responsible for the enhanced growth in larvae derived from parents exposed to heat. Together, my results provide evidence for a thermally induced transgenerational effect and a foundation for functional testing of candidate mechanisms mediating the effect.