Measure of the Ecological influence in Epigenetic-mediated Learning and memory formation in the Honeybee

Project Information

MeeLiH

Grant agreement ID: 798082

DOI

10.3030/798082

Project closed

EC signature date 4 April 2018

Start date 2 May 2018

End date 16 December 2020

Funded under

• EXCELLENT SCIENCE - Marie Skłodowska-Curie Actions

Total cost

€ 152 653,20

EU contribution

€ 152 653,20

Coordinated by

EREVNITIKO KENTRO VIOIATRIKON EPISTIMON ALEXANDROS FLEMINGK
Greece

Periodic Reporting for period 1 - MeeLiH (Measure of the Ecological influence in Epigenetic-mediated Learning and memory formation in the Honeybee)

Reporting period: 2018-05-02 to 2020-05-01

Summary of the context and overall objectives of the project

During the last decade, bee populations have suffered significant losses and collapse of entire colonies has increased dramatically around the world. Many factors appeared to be responsible for the weakening of bees and particularly due to the use of insecticides in agriculture. Given the dependence of agricultural crops on pollinators, there is a strong economic interest in anticipating the widespread decline of bees.
The memory and adaptation of bees are two cognitive skills that ensure the health and productivity of the colony. However, a growing number of scientific studies point toward an impairment of cognitive abilities in foragers when exposed chronically and even to low doses of pesticides from the neonicotinoid class. The difficulty in evaluating the impact of an exposure lies, in particular, in the lack of tools to evaluate the effects of pesticides under natural conditions and a limited knowledge of the fundamental mechanisms governing the molecular processes for the establishment of memory in honeybees.
The main objectives of this project were to 1/ develop a methodology able to directly assess under field condition the memory and behavioural adaptation capacities of honeybees exposed to pesticide, 2/ characterize the neuronal cells involved in the epigenetic remodelling during memory formation, 3/ Validate our observations by carrying out behavioural rescue experiments to mitigate the effects of the pesticide.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

In WP1, we tested the cognitive abilities of free-flying foragers and compared them to the cognitive abilities of foragers exposed to Sulfoxaflor, a pesticide recently released as an alternative to neonicotinoids. For this, we performed classical behavioural paradigms to test individual bee associative visual memory. We used learning and memory indexes combined with video tracking to identify the effects of the Sulfoximine-based pesticide on long-term memory.
Epigenetic marks are important genome remodelers in response to environmental changes and play an important role in establishing memory in honeybees. In WP2, we sought to characterize the neural network involved in epigenetic remodelling during memory formation. We have coupled super-resolution microscopy techniques allowing detection at the single cell level with methylome sequencing methods using the MinION (Oxford Nanopore Technology) portable sequencer, to identify the dynamic and positions of DNA methylations affected during exposure to a Sulfoximine-based pesticide.
Finally, in WP3, we tested two eco-innovative and field-based applicable approaches to mitigate the effects of Sulfoxalfor and improve the long-term memory of foragers. The restorative effects were demonstrated using the same memory evaluation indexes and molecular techniques described in the previous WPs.
As one of H2020's research priorities is to improve sustainable pollination, the dissemination of our work and our research interests were a priority during this fellowship. Specifically, the results of Dr Patalano's research to better understand the influence of the environment on the behaviour and epigenetics of social insects was shared within the scientific community, through the participation in international and national conferences, the establishment of collaborations within the host institute and the publication of scientific manuscripts (in progress). In addition, several actions of engagement with the general public were also carried out locally (with beekeepers and in schools) but also through public debates to promote the importance and the intelligence of the honey bee.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

Through this project we have contributed to the evaluation of sulfoximine-based insecticides recently introduced on the market and already widely used as an alternative to neonicotinoids by farmers. As the management and protection of pollinating insects is a priority for the European Union in order to ensure sustainable agricultural production, these results are likely to be used by the scientific community and integrated in the evaluation reports of Sulfoxaflor by European organizations such as the European Food Safety Agency (EFSA).
In addition, the socio-economic challenges for a transition to sustainable agriculture are significant and require the implementation of measures to mitigate the effects of environmental stressors such as pesticides. By testing strategies to limit the effects of sulfoximine on bee health, the MEELiH project participated in the environmental restoration measures of the EU Biodiversity Strategy for 2030 required by the new European Green Deal strategy.
Finally, the epigenetic mechanisms involved in the formation of memory described in this project contributed to the understanding of the fundamental processes of important cerebral functions conserved across species evolution. In the long term, the lines of research developed during this project will provide knowledge to the scientific community to better understand the impact of pesticide chronic exposure on cognition.

Foraging honeybee © P. Vardakas, BSRC ‘A. Fleming’