PT  - JOURNAL ARTICLE
AU  - Bertanne Visser
AU  - Hans T. Alborn
AU  - Suzon Rondeaux
AU  - Manon Haillot
AU  - Thierry Hance
AU  - Darren Rebar
AU  - Jana M. Riederer
AU  - Stefano Tiso
AU  - Timo J.B. van Eldijk
AU  - Franz J. Weissing
AU  - Caroline M. Nieberding
TI  - Phenotypic plasticity explains apparent reverse evolution of fat synthesis in parasitoid insects
AID  - 10.1101/2020.07.17.208876
DP  - 2021 Jan 01
TA  - bioRxiv
PG  - 2020.07.17.208876
4099  - http://biorxiv.org/content/early/2021/02/09/2020.07.17.208876.short
4100  - http://biorxiv.org/content/early/2021/02/09/2020.07.17.208876.full
AB  - Over the last few decades, numerous examples have been described where a trait that was once lost during the course of evolution had been regained. Here, we argue that such reverse evolution can also become apparent when trait expression is plastic in response to the environment. We tested this hypothesis for the loss and regain of fat synthesis in parasitic wasps. Wasps from lineages that supposedly regained lipogenic ability ~80 million years ago were grown under a fat-poor or fat-rich environment. In line with our hypothesis, it turned out that fat synthesis had not been lost and regained, but was only switched on in low-fat environments. Functional protein domains of key lipogenesis genes were also found in other parasitoid species, suggesting that plasticity of fat synthesis may be more widespread in parasitoids. Individual-based simulations then revealed that a switch for plastic expression can remain functional in the genome for thousands of generations, even if it is only used sporadically. The evolution of plasticity may thus also explain other examples of apparent reverse evolution.Competing Interest StatementThe authors have declared no competing interest.