Know more

Our use of cookies

Cookies are a set of data stored on a user’s device when the user browses a web site. The data is in a file containing an ID number, the name of the server which deposited it and, in some cases, an expiry date. We use cookies to record information about your visit, language of preference, and other parameters on the site in order to optimise your next visit and make the site even more useful to you.

To improve your experience, we use cookies to store certain browsing information and provide secure navigation, and to collect statistics with a view to improve the site’s features. For a complete list of the cookies we use, download “Ghostery”, a free plug-in for browsers which can detect, and, in some cases, block cookies.

Ghostery is available here for free:

You can also visit the CNIL web site for instructions on how to configure your browser to manage cookie storage on your device.

In the case of third-party advertising cookies, you can also visit the following site:, offered by digital advertising professionals within the European Digital Advertising Alliance (EDAA). From the site, you can deny or accept the cookies used by advertising professionals who are members.

It is also possible to block certain third-party cookies directly via publishers:

Cookie type

Means of blocking

Analytical and performance cookies

Google Analytics

Targeted advertising cookies


The following types of cookies may be used on our websites:

Mandatory cookies

Functional cookies

Social media and advertising cookies

These cookies are needed to ensure the proper functioning of the site and cannot be disabled. They help ensure a secure connection and the basic availability of our website.

These cookies allow us to analyse site use in order to measure and optimise performance. They allow us to store your sign-in information and display the different components of our website in a more coherent way.

These cookies are used by advertising agencies such as Google and by social media sites such as LinkedIn and Facebook. Among other things, they allow pages to be shared on social media, the posting of comments, and the publication (on our site or elsewhere) of ads that reflect your centres of interest.

Our EZPublish content management system (CMS) uses CAS and PHP session cookies and the New Relic cookie for monitoring purposes (IP, response times).

These cookies are deleted at the end of the browsing session (when you log off or close your browser window)

Our EZPublish content management system (CMS) uses the XiTi cookie to measure traffic. Our service provider is AT Internet. This company stores data (IPs, date and time of access, length of the visit and pages viewed) for six months.

Our EZPublish content management system (CMS) does not use this type of cookie.

For more information about the cookies we use, contact INRA’s Data Protection Officer by email at or by post at:

24, chemin de Borde Rouge –Auzeville – CS52627
31326 Castanet Tolosan CEDEX - France

Dernière mise à jour : Mai 2018

Menu Institut Sophia Agrobiotech Logo Marque Etat - République Française Logo_INRAE_noir Logo Université Côte d'Azur CNRS

Home page

Institut Sophia Agrobiotech

UMR INRA - Univ. Nice Sophia Antipolis - Cnrs

Project team "Genetics, Environment and Plasticity"

Insect models to understand the molecular mechanisms controlling phenotypic adaptation to the fluctuating environment.
Illustration of GEP team research

Etude des variations phénotypique et épigénétique du cycle de vie chez la drosophile

Phenotypic and epigenetic variation in D. melanogaster and in A. pisum.

(A) Drosophila life cycle and distribution of frequency- and density-dependent foraging (for) alleles depending on rearing conditions. Dark triangles: forR alleles. Red triangles: forS alleles. At high density (A and middle alignment of boxes) the forR allele predominates, whereas at low density (B and bottom alignment) the forS allele does. (B) An aphid ovariole stained in green for anti HRP (antibody which regognizes an epitope on the membrane). (C) Phenotypic variation of colors obtained from a single aphid mother founder. At 8°C, aphids change from orange to green. (D) Methyl-collected fragment analyzed by bisulfite sequencing to obtain the statistical analysis of methyl cytosine on multiple sites.

Research topics

A striking feature of insects is their ability to adapt rapidly to environmental changes, even for species as aphids that mostly reproduce clonally, reducing genetic variability. Aphids show indeed a high level of phenotypic plasticity, as illustrated by their aptitude to shift their reproduction mode depending on seasons, plant hosts and abiotic factors such as the temperature. However, mechanisms underlying this behavioral plasticity remain largely unknown.

Up to now, the dogma postulates that evolution and genome plasticity are written in the genetic code. In contrast, many recent reports describe that identical genomes might lead to different heritable characters depending on environmental factors. This leads to the new paradigm that environment induces heritable variants that might vanish with time when the conditions having induced them have disappeared. By which mechanisms a gene can be made durably active or inactive through generations when the genome sequences are identical? Recent advances to this question constitute the new active field of epigenetics.

Epigenetic marks are chemical modifications of DNA and histones that occur in all living organisms, mainly through methylation. We are interested in investigating the potential of stable epigenetic marks that might contribute to lasting and heritable phenotypes in insects. Although efficient transgenesis techniques do not yet exist for aphids as they do for Drosophila, the aphid Acyrthosiphon pisum model used in this proposal has a major advantage for epigenetic studies: aphids undergo parthenogenetic reproduction in spring and summer and sexual reproduction in fall, leading to fertilized eggs entering diapause during winter. We found that clonality in A. pisum generates a repertoire of phenotypic variants presenting a high degree of molecular polymorphism that seems stochastically produced and from which individual profiles are environmentally selected. We demonstrated that aphid variants in clonality context are correlated with methylation of the aphid genome and methylation of endosymbionts (unpublished data).


One objective of the team is to use the aphid model to determine the components of epigenetic regulation leading to adaptation to the environment. Our aim is to determine whether epigenetic marks, in particular genome methylation, induced by an extreme climate phase might be heritable across clonality (spring and summer) and also whether this heritability might pass the sexual barrier (fall and winter) to be transmitted in the newly emerged clonal generations the next spring, in order to achieve adaptation.

Although fascinating and important, the aphid model has limited genetic tools to decipher the mechanisms of epigenetic variation. Thus, we aim to couple aphid biology to Drosophila genetics in order to elucidate the underlying mechanisms at stake in insects. We plan, as a first step, to develop in Drosophila a genetic mutant-based approach to determine the role of known genes involved in DNA methylation on the regulation of “frequency- and density-dependent genes”. Another strategy will be to identify Drosophila homologous genes of aphid genes involved in epigenetic variations to unravel the underlying molecular mechanisms. The integration of these two models might highlight the molecular pathways leading to adaptation to fluctuating environments and the heredity of epigenetic marks in insects.