Phenotypic plasticity, trade-offs and gene expression changes accompanying dietary restriction and switches in Bactrocera dorsalis (Hendel) (Diptera: Tephritidae)

Er-Hu Chen,Dan-Dan Wei,Qiu-Li Hou,Jin-Jun Wang,Hong-Bo Jiang

doi:10.1038/s41598-017-02106-3

Abstract

In this study, we investigated the effects of dietary restriction (DR) and variable diets on phenotypes and gene expression in oriental fruit fly, Bactrocera dorsalis (Hendel), one of the most economically important pests in the family Tephritidae around the world. As expected, we found that DR altered the B. dorsalis phenotypes by significantly increasing stress resistance and lifespan, but reduced egg production when compared with the control diet. The results suggested a trade-off between reproduction versus somatic maintenance (stress resistance) and lifespan in B. dorsalis. Diet also had a significant effect on hatchability, and DR could increase the egg hatching success of B. dorsalis. Furthermore, DR up-regulated metabolic pathways involved in energy homeostasis and down-regulated pathways in egg production, which might mediate trade-offs between somatic maintenance and reproduction under DR regimes. The gene expression profiles in response to the acute dietary switches indicated that the digestive and metabolic pathways maybe involved in the adaptability of flies to variable dietary resources. In summary, the research facilitates a better understanding of the molecular mechanisms responsible for the B. dorsalis’ phenotypic adjustments to the different qualities of the available diets.

Highlights

Phenotypic plasticity, the ability of animals to adjust their developmental, physiological or behavioural phenotypes to variable environments, is critical for their survival[1]
B. dorsalis developed on the dietary restriction (DR) treatment had longer survival times than flies developed on the control diets (CD) (Kolmogorov-Smirnov test, nDR = 42; nCD = 35, Z = 3.13, P < 0.001) (Fig. 1A), with mean survival times of 7.73 ± 0.41 and 2.32 ± 0.08 days, respectively (P < 0.001) (Fig. 1B)
The current study strongly suggested a trade-off between reproduction and stress resistance, as well as lifespan, depending on the quality of the available diet, which confirmed the theory of energy or resource allocation trade-offs in B. dorsalis

Summary

Introduction

Phenotypic plasticity, the ability of animals to adjust their developmental, physiological or behavioural phenotypes to variable environments, is critical for their survival[1]. The responses of stress resistance, life-history traits and reproduction to dietary quality are important and familiar examples of phenotypic plasticity[2]. Little is known about the effects of DR and dynamic diets on the phenotypes (the responses of stress resistance and hatchability to DR; the responses of lifespan and fecundity to dynamic diets) and gene expressions in B. dorsalis. We investigated the effects of chronic DR and control diets (CD) on the plasticity of lifespan, fecundity, stress resistance (starvation, desiccation, heat and cold resistance), hatchability and gene expression in B. dorsalis. The aim of this study was to facilitate a better understanding of the molecular mechanisms responsible for phenotypic adjustments in B. dorsalis to the nutritional stress and fluctuating dietary conditions

Objectives

Methods

Results

Discussion

Conclusion