Transgenerational response to early spring warming in Daphnia

Kenji Toyota,Antonio Suppa,John K Colbourne,Maria Cambronero Cuenca,Valeria Rossi,Luisa Orsini,Vignesh Dhandapani

doi:10.1038/s41598-019-40946-3

Abstract

Temperature and photoperiod regulate key fitness traits in plants and animals. However, with temperature increase due to global warming, temperature cue thresholds are experienced at shorter photoperiods, disrupting the optimal seasonal timing of physiological, developmental and reproductive events in many species. Understanding the mechanisms of adaptation to the asynchrony between temperature and photoperiod is key to inform our understanding of how species will respond to global warming. Here, we studied the transgenerational mechanisms of responses of the cyclical parthenogen Daphnia magna to different photoperiod lengths co-occurring with warm temperature thereby assessing the impact of earlier spring warming on its fitness. Daphnia uses temperature and photoperiod cues to time dormancy, and to switch between sexual and asexual reproduction. Daphnia life cycle offers the opportunity to measure the relative contribution of plastic and genetic responses to environmental change across generations and over evolutionary time. We use transgenerational common garden experiments on three populations ‘resurrected’ from a biological archive experiencing temperature increase over five decades. Our results suggest that response to early spring warming evolved underpinned by a complex interaction between plastic and genetic mechanisms while a positive maternal contribution at matching environments between parental and offspring generation was also observed.

Highlights

Organisms respond to changing environments by shifting their distribution, via genetic adaptation or through plasticity of fitness related traits[1]
Www.nature.com/scientificreports role of adaptive transgenerational plasticity is key to predict the consequences of parental effects on population dynamics, and to inform our understanding of how species will respond to rapid environmental change[18]
Plastic changes in age at maturity were significantly associated with the rhodopsin g-protein coupled receptor; plastic changes in fecundity were significantly associated with the Histone deacetylase complex subunit SAP18; variation in male offspring proportion was significantly associated with Amino-oxidase, SAP18, Phosphotyrosine (PTB), and Aldo/keto reductase; plastic change in size at maturity was significantly associated with Pyridine nucleotide-disulphide oxidoreductase, PTB, SAP18, and an RNA binding protein (Table S3). Investigating both plasticity and genetic adaptation across generations enables to establish a link between evolutionary potential and TGP52–54

Summary

Introduction

Organisms respond to changing environments by shifting their distribution, via genetic adaptation or through plasticity of fitness related traits[1]. Within-generation plasticity (WGP) is advocated as the main mechanism of response to environmental change, allowing for rapid adjustments to novel environmental conditions[4,5,6] This consensus is subject to a scarcity of studies on the mechanisms of genetic adaptation to environmental change, because of the significant challenges at identifying the genetic elements underpinning adaptive phenotypic trait variation in nature[1,3,7]. Www.nature.com/scientificreports role of adaptive transgenerational plasticity is key to predict the consequences of parental effects on population dynamics, and to inform our understanding of how species will respond to rapid environmental change[18]. We study within-generation plastic and genetic responses, as well as the cross-generational responses of fitness-linked life history traits to environmental conditions that mimic early spring warming (warm temperature and short photoperiod) as compared to a typical spring environment (warm temperature and long photoperiod)

Methods

Results

Conclusion