A queen's tale: An experimental palaeoproteomic study of a honey bee queen cell specimen from Natural History Museum Denmark.

BACKGROUND: Natural history museum specimens of historical honey bees have been successfully used to explore the genomic past of the honey bee, indicating fast and rapid changes between historical and modern specimens, possibly as a response to current challenges. In our study we explore a potential untapped archive from natural history collections - specimens relating to historical beeswax. METHODS: We examine an Apis mellifera mellifera queen cell specimen from the 19th century. The intact and closed cell was analysed by X-ray Computed Tomography (CT) to reveal a perfectly preserved queen bee inside her cell. Subsequently, a micro-destructive approach was used to evaluate the possibility of protein extraction for a palaeoproteomic approach. RESULTS: Using proteomics by liquid-chromatography-tandem mass spectrometry, we were able to recover 120 non-contaminant proteins, mostly bee-related, including major royal jelly proteins (MRJPs) crucial for queen nutrition and development, and silk fibroin proteins. Analysis of the protein modifications indicate their endogenous source and show the presence of in vivo glycosylation. This probably helped protein preservation and allows for the study of antimicrobial and metabolic functions of bees in the past. CONCLUSION: Our exploratory results show that studies on specimens such as these can provide biomolecular information. Such specimens can inform future research on queen development, diet, and hive conditions, providing valuable context for understanding how honey bee populations have responded to changing environments and pressures over time. This highlights further the scientific potential of natural history collections in addressing contemporary challenges in honey bee conservation and health.