Project description:Recent improvements in the analysis ancient biomolecules from human remains and associated dental calculus have provided new insights into the prehistoric diet and past genetic diversity of our species. Here we present a “multi-omics” study, integrating genomic and proteomic analyses of two post-Last Glacial Maximum (LGM) individuals from San Teodoro cave (Italy), to reconstruct their lifestyle and the post-LGM resettlement of Europe. Our analyses show genetic homogeneity in Sicily during the Palaeolithic, representing a hitherto unknown Italian genetic lineage within the previously identified “Villabruna cluster”. We argue that this lineage took refuge in Italy during the LGM, followed by a subsequent spread to central-western Europe. Analyses of dental calculus using genomics and proteomics showed a similar oral microbiome composition as Neandertals, but distinct from later foragers and farmers, revealing also a diet based on mammals, fish and plants. Our results demonstrate the power of using a multi-omics approach in the study of prehistoric human populations.
Project description:The little skate, a cartilaginous fish evolutionarily distal from tetrapods, displays walking-like behavior and has conserved genetic programs and neuronal substrates for land-walking. Studies on little skate have been limited due to lack of high-quality genome assembly. Here, we generated an improved genome assembly of little skate reflecting precise gene annotation and structures and performed integrated analysis of gene expression and chromatin accessibility to investigate molecular mechanisms of fin motor neuron development. Through interspecies comparison of RNA expression, common and species-specific genes expressed in fin/limb/wing level motor neurons were identified. Moreover, by performing chromatin accessibility analysis with a pure fin motor neuron population the potential regulators controlling the gene expression in fin motor neurons were identified. Interspecies comparison of genomic data, gene expression, and chromatin accessibility assay suggest that the little skate has highly conserved gene regulatory mechanisms controlling tetrapod locomotion, which was not previously expected.
Project description:The archetypical venomous lizard species are the helodermatids, the Gila Monster (Heloderma suspectum) and the Beaded Lizards (Heloderma horridum). In the present study, the gila monster venom proteome was characterized using 2D-gel electrophoresis and tandem mass spectrometry-based de novo peptide sequencing followed by protein identification based on sequence homology. A total of 39 different proteins were identified out of the 58 selected spots that represent the major constituents of venom. Of these proteins, 19 have not previously been identified in helodermatid venom. The data showed that helodermatid venom is complex and that this complexity is caused by genetic isoforms and post-translational modifications including proteolytic processing. In addition, the venom proteome analysis revealed that the major constituents of the gila monster venom are kallikrein-like serine proteinases (EC 3.4.21) and phospholipase A2 (type III) enzymes (EC 3.1.1.4). A neuroendocrine convertase 1 homolog that most likely converts the proforms of the previously identified bioactive exendins into the mature and active forms was identified suggesting that these peptide toxins are secreted as proforms that are activated by proteolytic cleavage following secretion as opposed to being activated intracellularly. The presented global protein identification-analysis provides the first overview of the helodermatid venom composition.
Project description:YerA41 is a myoviridae bacteriophage that was originally isolated due its ability to infect Yersinia ruckeri bacteria, the causative agent of enteric redmouth disease of salmonid fish. Several attempts to determine its genomic DNA sequence using traditional and next generation sequencing technologies failed, indicating that the phage genome is modified such way that it is an unsuitable template for PCR amplification and sequencing. To determine the YerA41 genome sequence we isolated RNA from phage-infected Y. ruckeri cells at different time points post-infection, and sequenced it. The host-genome specific reads were substracted and de novo assembly was performed on the unaligned reads.