Project description:In recent years, sediments from cave environments have provided invaluable insights into ancient hominids, as well as past fauna and flora. Unfortunately, locations with favourable conditions for ancient DNA (aDNA) preservation in sediments are scarce. In this study we analysed a set of samples obtained from sediments adhered to different human skeletal elements, originating from Neolithic to Medieval sites in England, and performed metagenomics and metaproteomics analysis. From them, we were able to reconstruct a partial human genome. The genetic profile of those human sequences matches the one recovered from the original skeletal element. Additionally, aDNA sequences matching the genomes of endogenous gut and oral microbiome bacteria were identified. We also found the presence of genetic sequences corresponding to animals and plants. In particular we managed to retrieve the partial genome and proteome of a Black Rat (Rattus rattus), sharing close genetic affinities to other medieval Rattus rattus. Our results demonstrate that material usually discarded, as it is sediments adhering to human remains, can be used to get a glimpse of the environmental conditions at the time of the death of an individual.
Project description:Major urinary proteins (MUP) are the major component of the urinary protein fraction in house mice (Mus spp.) and rats (Rattus spp.). The structure, polymorphism and functions of these lipocalins have been well described in the western European house mouse (Mus musculus domesticus), clarifying their role in semiochemical communication. The complexity of these roles in the mouse raises the question of similar functions in other rodents, including the Norway rat, Rattus norvegicus. Norway rats express MUPs in urine but information about specific MUP isoform sequences and functions is limited. In this study, we present a detailed molecular characterization of the MUP proteoforms expressed in the urine of two laboratory strains, Wistar Han and Brown Norway, and wild caught animals, using a combination of manual gene annotation, intact protein mass spectrometry and bottom-up mass spectrometry-based proteomic approaches. Detailed sequencing of the urinary MUP isoforms reveals a less complex pattern of primary sequence polymorphism in the rat than the mouse. However, rat MUPs exhibit added complexity in the form of post-translational modifications, including the phosphorylation of Ser4 in some isoforms, and exoproteolytic trimming of specific isoforms.