Understanding the processes enabling adaptation to time-varying environments is critically relevant in evolutionary ecology. A way to cope with environmental fluctuations where predictable conditions affect several generations is through non-genetic transgenerational effects. Sexual reproduction in rotifers is inhibited in several generations after diapause, but no study relating this transgenerational effect to environmental predictability has been done, its molecular basis being also unknown. Hence, we studied (1) the proportion of sexual reproduction (PSR) along successive clonal generations from diapausing eggs in eight Brachionus plicatilis populations inhabiting ponds with different levels of environmental predictability, and (2) the expression level of genes related to sex in rotifers (17-β-estradiol dehydrogenase, edh) and epigenetic signaling mechanisms (DNA methyltransferase, dnmt) in a subset of populations in our study system. Results show that clones from more predictable ponds were unresponsive to sex-inducing cues for a higher number of generations after leaving diapause. Instead, clones from more unpredictable ponds did respond to sex-inducing cues from early generations, likely to ensure diapausing egg production. Besides, edh increased its expression across generations and correlated positively with PSR, suggesting that edh is involved in the manifestation of sex. Differences were neither found in the expression of dnmt among generations nor between populations, pointing out that methylation may not be involved in the observed transgenerational effect.

Primary Presenter: Noemi Colinas Vallejo, University of Valencia (noemi.colinas@uv.es)

Authors:

Noemi Colinas, University of Valencia  (noemi.colinas@uv.es)

María José Carmona, University of Valencia  (carmona@uv.es)

Manuel Serra, University of Valencia  (Manuel.serra@uv.es)

Javier Montero-Pau, University of Valencia  (Javier.montero@uv.es)

Raffaella Sabatino, National Research Council of Italy, Water Research Institute (CNR-IRSA)   (raffaella.sabatino@irsa.cnr.it)

Andrea Di Cesare, National Research Council of Italy, Water Research Institute (CNR-IRSA)  (andrea.dicesare@cnr.it)

Ester Maria Eckert, National Research Council of Italy, Water Research Institute (CNR-IRSA)  (estermaria.eckert@cnr.it)

Eduardo M García-Roger, University of Valencia  (eduardo.garcia@uv.es)