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 INRA Clermont Auvergne University


Joint Research Unit 1095 Genetics, Diversity and Ecophysiology of Cereals

Task 1 : Evolution

Principle : Modern species are paleopolyploids deriving from diploid extinct ancestors.

Paleogenomics, the study of ancestral genome structure of modern species, allows the identification and characterization of mechanisms (i.e. duplications, translocations, and inversions) that have shaped the genome of present-day living species during their evolution. Two scientific approaches can be investigated to address this issue. The first consists in sequencing (at least partially) fossil DNA from recovered ancestral genome structures. The second approach, when fossil DNA is not available, can be performed through large-scale comparative analyses of modern species and then ancestor modeling in term of its paleo-chromosome structure and gene content. The ancestor modeling procedure consists in identifying the minimal genomic structure (gene content and order) considered to be ancestral, based on the synteny-based comparison of present-day genomes. Unlike mammals, paleogenomics is still little studied in plants, and more specifically in angiosperms that have undergone a large number of segmental or even global genome duplications (polyploidization) as well as local rearrangements (gene inversion, tandem duplication or conversion), making difficult to carry out robust comparative genomics studies in monocotyledons (mainly cereals) and eudicotyledons.  

The development of bioinformatics, statistical and combinatorial mathematical tools has enabled us to characterize and validate syntenic and duplication relationships in plant genomes (Arabidopsis, soybean, poplar, papaya, vine, rice, maize, sorghum, barley, Triticeae, Brachypodium…) and made then possible to characterise ancestral duplication events (that are by sense common to the considered genomes), as well as duplication events specific to each of them. For the first time, the integration of duplication and syntenic relationships offers the opportunity to characterise seven paleoduplications present in the studied genomes. We have thus been able to model both the genome of extinct plant ancestors, as well as an evolutionary scenario that has shaped the genome of modern plant species.

Our research has established in the field of plant paleogenomics that:

  • Monocotyledons arise from an ancestor structured with seven protochromosomes carrying 9138 protogenes, and the eudicotyledons come from an ancestor with seven protochromosomes carrying 9731 protogenes.
  • Based on these ancestors, the evolutionary paleohistory of present-day plants involves four major events.
  • Of these events, whole genome duplication (polyploidy) appears as a major force for the adaptation of plants to their environment.

Evolutionary scenario of the plant genomes (Salse et al. 2012) The present-day monocot (right) and eudicot (left) genomes (bottom) are represented with color codes to illustrate the evolution of segments from their founder ancestors with seven protochromosomes according to the time scale (left in mya). The WGD events that have shaped the structure of the modern plant genomes during their evolution are indicated as red dots.