Project description:During embryonic development, the mesenchyme surrounding the brain (cranial mesenchyme) gives rise to several structures such as the meninges, calvaria, and the dermis of the scalp. It has been known that the two regions within the cranial mesenchyme, namely, SOM on the basolateral side and EMM on the apical side of the head, have different developmental fates. However, the molecular genetic basis underlying this difference had been unclear. To address this question, we sought to identify genes differentially expressed between EMM and SOM. Through RNAseq, we identified 1095 genes with higher expression in EMM than in SOM, and 398 genes with higher expression in SOM than in EMM (fold change>2, p<0.001, base mean count>50).
Project description:Chagas disease is one of the most important neglected diseases with an estimated number of 12 million infected individuals, the majority living in Central and South America. The Trypanosoma cruzi (T.cruzi) protozoan parasite is the etiological agent of Chagas disease. T.cruzi is highly genetically diverse and a new nomenclature assigned each strain to seven genetic groups (TcI-TcVI and Tcbat), named Discrete Typing Units (DTUs), based on their biochemical, immunological and phenotypical characteristics. T.cruzi DTUs have been correlated to diverse clinical outcomes highlighting the importance of molecular epidemiological screens. Despite the development of T.cruzi typing methods based on genetic signatures, each method presenting its own advantages and challenges. The work presented here shows the application of mass spectrometry for Trypanosoma cruzi Strain Typing Assay using MS2 peptide spectral libraries (Tc-STAMS2). The novelty of the method is based on the use of peptide fragmentation spectra as strain-specific fingerprints to classify and identify DTUs. Initially, a spectra library is generated from characterized T.cruzi strains. The library is subsequently inspected using MS/MS spectra from unknown strains and confidently assigned to a specific strain in an automated and computationally-driven approach. The Tc-STAMS2 method was challenged to test several variables such as sample type and preparation, instrument setup and identification platform. Tc-STAMS2 provided high confidence and robustness in T.cruzi strain typing. The Tc-STAMS2 method represents a proof-of-concept of a complementary strategy to the current DNA-based T. cruzi genotyping methods. Moreover, the method allows the identification of strain-specific features that could be related to the biology of T.cruzi strains and their clinical outcomes.
