In March 2022, the Senate of the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) established the Priority Programme “CodeChi – Chitin, chitosan and chito-oligosaccharides and their interaction with proteins of the extracellular matrix and cellular signaling” (SPP 2416). The programme, which is designed to run for six years, started at the end of 2023. The present call invites proposals for the second three-year funding period.

Objectives and Scope of the Programme

Although notably absent in plants and vertebrates, chitin and chitosans (C/CS) rank among the most abundant and versatile polymers in nature, serving as essential components of extracellular matrices across a wide range of organisms, including arthropod cuticles and fungal cell walls. In these organisms, C/CS form the structural basis of diverse biomaterials with an exceptional range of physicochemical and mechanical properties. Moreover, C/CS and, in particular, C/CS-derived oligomers (COS) from C/CS-containing organisms interact with and affect other organisms, including non-C/CS-containing eukaryotic cells in plants, animals and humans, in multiple and profound ways. 

A growing body of evidence indicates that sugar polymers like C/CS encode biologically relevant information. It is the molecular fine structure of C/CS, defined by the degree of polymerisation (DP) as well as the degree and pattern of acetylation (DA and PA), which carries information and plays a decisive role in determining the physicochemical and biological properties of C/CS-containing matrices and functional materials. Beyond these widespread and diverse structural roles, COS – e.g. generated through the action of C/CS-degrading enzymes of C/CS-producing organisms, but also in the environment and host species – function as potent information-bearing molecules. Building on this premise, we hypothesised and showed that the fine-structure of C/CS and COS constitutes a molecular information system, herein referred to as “CodeChi”. This code is “written”, “enacted” and “interpreted” by a diverse repertoire of C/CS-synthesising and -modifying enzymes and C/CS-binding proteins in organisms that produce these polymers, as well as by C/CS-degrading enzymes and COS-binding receptors in environmental hosts that interact with C/CS-containing organisms. 

The overall aim of this Priority Programme is to decipher CodeChi, elucidating the molecular, structural and biophysical principles governing C/CS/COS function in biological systems. By integrating fundamental biological and chemical research with materials-orientated approaches, the programme seeks not only to advance a mechanistic understanding of C/CS/COS biology but also to leverage this knowledge for the rational design and fabrication of novel functional materials. In the first funding period, the Priority Programme was centred around two main questions, which were addressed in different synthetic models as well as in biological systems including protists, fungi, plants, insects and mammals: (1) How are C/CS-based matrices organised into higher-order structures by C/CS-binding proteins interpreting CodeChi to generate a large variety of extracellular matrices with different physicomechanical properties? (2) How are COS generated in biological systems, and which precise CodeChi characteristics (i.e. DP, DA and PA) trigger their recognition by immune receptors? To facilitate this research, the Priority Programme established three central Service Projects, providing chemically defined COS and chitosan polymers, as well as recombinant C/CS-binding proteins, and enabling interaction analyses of defined C/CS/COS with chitin-binding proteins/receptors. 

In the second funding period, the Priority Programme will continue elucidating the biological significance of CodeChi in established and new biological systems and expanding structure-function analyses between defined C/CS/COS and binding proteins/receptors. In addition, the knowledge gained about writing, enacting and interpreting CodeChi will be utilised for the preparation of novel functional materials, e.g. for drug-delivery, tissue engineering and plant protection. The Service Projects will continue to support the programme’s research projects by providing defined C/CS/COS and analytical capabilities, while further refining techniques to improve and broaden synthesis and analysis efficiencies. 

Successful proposals are expected to advance the overarching scientific goals of the Priority Programme by elucidating the role of CodeChi in regulating the biosynthesis, modification and degradation of C/CS, uncovering the design principles of C/CS-containing extracellular matrices and defining the structure-function relationships of C/CS-interacting proteins, enzymes and receptors, that mediate COS-triggered immune reactions. In this second round, we are particularly seeking projects which build on substantial prior work strongly suggesting a role for CodeChi in the system investigated. We encourage researchers to submit proposals going beyond the goals of the first funding period by addressing CodeChi’s higher-order roles in, for instance, remodelling extracellular matrices or regulating immune responses, implementing CodeChi into functional materials or investigating CodeChi by systems biology approaches. Detailed information on the research programme, its interdisciplinary approach and scientific community can be obtained on the website of the programme (see link below). Projects limited to descriptive approaches of only identifying new C/CS-related enzymes, binding proteins or receptors, or to approaches focusing on C/CS-based materials without addressing CodeChi principles, are outside the scope of the Priority Programme.

Preparatory Meeting

Scientists who are interested in submitting a proposal for an individual or a joint project in the second funding period are invited to a preparatory meeting hosted by the programme committee and held on 21 April 2026, which will take place online and be announced on the CodeChi website. In this meeting, the background and the organisational structure of the Priority Programme will be presented. Furthermore, break-out sessions will facilitate networking amongst potential applicants. Participation in this meeting is not a prerequisite but highly recommended for the submission of proposals under this programme. Scientists who are interested are requested to register by 10 April 2026 via the CodeChi website. We strongly encourage all interested parties to submit a short outline of the project idea together with the contact data, a summary of expertise and two to three references of relevant articles by this date. These data will be made accessible to all PIs who have registered via a protected area of the CodeChi website.

Proposal Submission

Please submit your proposal to the DFG by 24 June 2026. Proposals are to be submitted solely via the elan portal(externer Link) in order to ensure proposal-related data is recorded and documents are securely transmitted. To submit a new project within the existing Priority Programme, go to Proposal Submission – New Project/Draft Proposal – Priority Programmes and then select “SPP 2416” from the current list of calls. Previous applicants can submit a proposal for the renewal of an existing project under Proposal Submission – Proposal Overview/Renewal Proposal.

When preparing your proposal, please refer to the guideline (DFG form 50.05(interner Link), section B) and follow the proposal preparation instructions (DFG form 54.01(interner Link)). In addition to submitting your proposal through elan, please also send an electronic copy to the programme coordinator.

If this is the first time you are submitting a proposal to the DFG, please note that you must register in the elan portal before you can submit your proposal. You must do so by 17 June 2026. You will normally receive confirmation of your registration by the next working day.

Equity and Diversity

The DFG strongly welcomes proposals from researchers of all genders and sexual identities, from different ethnic, cultural, religious, ideological or social backgrounds, from different career stages, types of universities and research institutions, and with disabilities or chronic illness. With regard to the subject-specific focus of this call, the DFG encourages female researchers in particular to submit proposals.

Good Research Practice

According to a resolution of the DFG General Assembly, DFG funding may only be awarded to research institutions that have implemented the guidelines laid down in the Code of Conduct for Safeguarding Good Research Practice(externer Link) in their own regulations. The management of your institution is responsible for implementing the guidelines in a legally binding manner. In order to avoid delays in the disbursement of funding, please verify implementation within your institution in good time. For information regarding the implementation, please refer to the Research Integrity Portal(externer Link). If you have any questions on this subject, please contact the Research Integrity team(externer Link) at the DFG Head Office. 

Further Information 

Please find detailed information on the Priority Programme here(externer Link).

When submitting proposals, please use the elan portal(externer Link) and refer to the respective guidelines DFG form 50.05(interner Link) and DFG form 54.01(interner Link). The FAQ on Proposal Submission(externer Link) may also be helpful.

For scientific enquiries, please contact the Priority Programme coordinator:

Prof. Dr. Hans Merzendorfer, Department Chemie-Biologie, Abt. Molekularbiologie, Universität Siegen, 57068 Siegen, Tel.: +49 271 740 3917, hans.merzendorfer@uni-siegen.de(externer Link)

Contact Persons at the DFG Head Office

Programme contact: Dr. Nikolai Raffler, Tel. +49 228 885-2441, nikolai.raffler@dfg.de(externer Link)

Administrative contact: Sarah van Goch, Tel. +49 228 885-2373, sarah.goch@dfg.de(externer Link)

Privacy Policy

We, the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation), take the protection of your personal data and its confidential treatment extremely seriously. Therefore, please refer to the DFG’s Privacy Policy(interner Link). If you intend to transmit personal data of third parties, please make sure to do so only if the necessary legitimation under data protection law exist. Before transmitting data of third parties to the DFG, please forward the DFG’s Data Protection Notice to the individuals affected (data subjects). If there is a legitimate interest not to inform individuals beforehand (e.g. for reasons of secrecy or in case of a nomination or candidate proposal), these individuals should be informed no later than at the time of publication.