Glycoprotein (Glyco+protein) of the biomineralized eggshell in birds

Informations projet

GlycoEggshell

N° de convention de subvention: 101106296

DOI

10.3030/101106296

Projet clôturé

Date de signature de la CE 15 Mars 2023

Date de début 1 Juin 2023

Date de fin 31 Mai 2025

Financé au titre de

• Marie Skłodowska-Curie Actions (MSCA)

Coût total

Aucune donnée

Contribution de l’UE

€ 214 934,40

Coordonné par

KOBENHAVNS UNIVERSITET
Denmark

Periodic Reporting for period 1 - GlycoEggshell (Glycoprotein (Glyco+protein) of the biomineralized eggshell in birds)

Période du rapport: 2023-06-01 au 2025-05-31

Résumé du contexte et des objectifs généraux du projet

The GlycoEggshell aims to describe and elucidate specific roles of glycosylation on eggshell proteins across birds and evolutionary times, using modern and sub-fossil samples. The project has three main research objectives:
• RO1: Characterize glycosylated proteins in eggshells to assess the glycosylation patterns across different bird clades and understand the correlation between glycosylation and eggshell characteristics.
• RO2: Characterize the glycosaminoglycan (GAG) compositions and structures in eggshells to trace changes in GAG types, sulfation status, and sulfation positions across evolutionary time and among bird groups.
• RO3: Investigate GAG–protein interactions to identify GAG structures that bind to lectins, thereby elucidating the potential role of lectins in the eggshell matrix.
The impact of the GlycoEggshell project is substantial and far-reaching. It:
1. Provides a novel platform for sugar characterization in environmental samples;
2. Develops a comprehensive avian glycome database accessible to academia, industry, and the public;
3. Opens new avenues for the emerging field of Palaeoglycomics, with applications in archaeology and palaeontology;
4. Trains the next generation of European scientists to drive glycoscience-based research on ancient biomolecules.

Travail effectué depuis le début du projet jusqu’à la fin de la période considérée dans le rapport et principaux résultats atteints jusqu’à présent

Work Package 1:
I characterized glycan structures across different bird clades using western blot and mass spectrometry. We identified the presence of sulfated O-glycans in mineralized tissues of birds - an observation that, to our knowledge has not been previously documented. Additionally, we observed species-specific variations in P1 lectin staining.
Work Package 2:
I analyzed the GAG components and compositions in both modern and ancient bird eggshells. The GAGs identified include heparan sulfate (HS), chondroitin sulfate (CS), hyaluronic acid (HA), and keratan sulfate (KS). We proved that GAGs could survive in the ancient eggshell (at least 1,000 years and we are in the final process to verify this in 6 million years old sample). Our analysis showed that chondroitin sulfate was the most abundant across all bird groups. Within CS, chondroitin 4-sulfate and non-sulfated chondroitin were the most dominant disaccharide subtypes.
Work Package 3:
This work package was not initiated during the fellowship period due to time constraints. However, the results from RO1 and RO2 are robust and publishable, laying the foundation for RO3. We aim to explore GAG–protein interactions in the coming months to further understand the functional roles of these biomolecules in the eggshell matrix.

Progrès au-delà de l’état des connaissances et impact potentiel prévu (y compris l’impact socio-économique et les conséquences sociétales plus larges du projet jusqu’à présent)

The GlycoEggshell project pioneers the characterization of sugars in bird eggshells with the aim of developing a glycomic database to trace avian evolution and support species identification across time periods. Our data demonstrates that GAG can survive in eggshells for at least 1,000 years. This resilience is likely because relatively few organisms metabolize these specific sugar types. In addition, from our heat modelling assay, the GAGs are heat resistant and hence increase the chance of their survival in ancient context.
If GAGs can be detected in eggshells as old as 6 million years, they may serve as valuable biomarkers for reconstructing avian diets, ecologies, and species identification during the Miocene period and beyond.
The project's first major outcome is the creation of accessible glycomic resources for academic researchers, industrial stakeholders, and the general public. In the long term, these glycans may serve as novel biomarkers for species identification and provide new insights into ancient dietary behaviors and ecological conditions.
As the calcareous egg is the universal reproductive medium for birds, GlycoEggshell investigates the main organic matrix component—glycoproteins—which are crucial for eggshell biomineralization. These data also support the development of subsequent studies, such as using stable isotope analysis to investigate avian diets and potential environmental contamination during the breeding season. This work could offer valuable tools for understanding the past and present global environmental changes.

GlycoEggshell Concept