Interest in epigenetics and epigenetic inheritance has grown rapidly over the last few decades, driven by fundamental biological discoveries with broad clinical and agricultural applications. Yet, a small group of established biological model organisms - particularly rodents, fruit flies, nematodes and plants such as Arabidopsis thaliana, rice and maize - has been widely used to investigate mechanisms underlying heritable, non-genetic changes in phenotype. Although they are powerful, relying exclusively on these models can also be limiting. We instead advocate for a question-driven approach for investigation of epigenetic inheritance, where research problems guide model selection and the consequent exploration of novel models - animal, plant and microbe. A prime example of this framework is the study of the 'dynamics' of epigenetic inheritance, that is, the rates at which epigenetically inherited marks, associated phenotypes and regulatory effects appear, persist and fade across generations. Investigation of this poorly understood phenomenon requires models that are suited to tracking multigenerational phenotypic changes. Thus, effective organismal model selection necessitates practical considerations, such as ease of husbandry, length of the lifespan, the existence of quantifiable phenotypes and permissiveness to epigenetic manipulation. To exemplify the exploration of novel biological systems, we present microalgae as an underutilized yet promising model system particularly suited to evaluating the dynamics of epigenetic inheritance, although other organisms may better suit questions focused on sexual reproduction or complex development. By offering microalgae as one illustrative case study, we emphasize the broader need to align organismal model choice with research questions and to expand beyond traditional systems.
Steadman et al. (Fri,) studied this question.