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

Btk toxins influence progenitor cell fate of intestinal stem cell

Friday, April 13 - 11:00 - Sophia Antipolis - Inra PACA - Room A010

Séminaire scientifique
As part of the scientific animation of Institut Sophia Agrobiotech, , Rouba JNEID, PhD in BES team, will present: "Btk toxins influence progenitor cell fate of intestinal stem cell"


In order to reduce the use of chemical pesticides, organic farming are using biopesticides.
Bacillus thuringiensis var kurstaki (Btk) is the most used biopesticide around the world. Btk is a Gram positive soil bacterium. When resources are limited, vegetative Bt cells undergo sporulation, synthesizing a protein crystal during spore formation. Proteins in these crystals are called Cry endotoxins and have been known for decades to display insecticidal activity against specific insect groups by destroying their gut and leading to their death by septicemia.
My PhD project aims to study the impacts of Btk on the gut homeostasis of non-target organisms. For that, I will use the powerful laboratory model Drosophila melanogaster.
In the Drosophila midgut, Intestinal Stem Cells (ISCs) are required for maintenance of the proper cell composition in the adult intestine. To ensure permanent recruitment of newly differentiated cells, ISCs undergoe asymmetric cell division that generates an ISC itself and a progenitor cell. Then, the level of Notch pathway activation in progenitor cells will commit them toward enterocytes (at high Notch activation) or enteroendocrine cells (at low Notch activation) differentiation. Upon a bacterial intoxication that causes gut damages, intestinal cell renewing is accelerated and most of progenitor cells differentiate into enterocytes to replenish the damaged ones.
Strikingly, our work revealed that the number of enteroendocrine cells (EEC) increases after an intoxication by the commercialized form of Btk despite the damages caused to the enterocytes. We have shown that this EEC increase is dependent on the Cry toxins.
My work is to understand how Btk induces an increase in EECs at the expense of enterocyte differentiation and the putative link between Cry toxins and the inhibition of Notch pathway. 


Bioinsecticides, Bacillus thuringiensis (Bt), Drosophila melanogaster, intestinal homeostasis , Cry toxins , Notch pathway .