Resumen
I) mRNA targeting and protein synthesis in axons.
A substantial number of studies over a period of four decades have indicated that axons contain mRNAs and ribosomes, and are metabolically active in synthesizing proteins locally. For the most part, little attention has been paid to these findings until recently when the concept of targeting of specific mRNAs and translation in subcellular domains in polarized cells emerged to contribute to the likelihood and acceptance of mRNA targeting to axons as well. Main contributions are: i) the finding of neuro-specific mRNAs in axons in vivo, providing one of the first evidences that transport of mRNA and protein synthesis could be occurring in mature myelinated axons; ii) the characterization of novel ribosome containing domains in myelinated axons as compartment-like structures specialized in mRNA localization and protein translation as a conserved domain from bony fishes to mammals, where Actin mRNAs, RNA binding proteins, molecular motors and ribosomes are localized. Current work aims to characterize the mRNAs present in motor and sensory axons and their translation and modulation of translation using genomic strategies.
II) Genomics.
During the postdoctoral period (2006-2010) I have trained in genomics at the National Cancer Institute-NIH, thanks to a PEW fellowship for Latin American scientists. The activities were centered in two areas: technology development and research using genomics approaches. In the first area, I collaborated in developing antibody arrays, microRNA arrays, virus detection arrays (using Affymetrix and Agilent platforms) to be used in a variety of projects. In the same venue mass sequencing approaches, for mutation detection from mRNA and evaluation of mRNA translation in polysomes were developed (Ribo-seq). On the research side, it was possible to establish for the first time that cMyc oncogene was regulated via TCF4/Catenin complex through an enhancer region located 300kB away from its promoter, in prostate and colon cancer.
Continuing with the development of this area in our community I have settled an integrated genomics department and a deep sequencing platform, together with hardware/software to handle and analyze data from diverse genomics platforms. Current research includes: transcriptome analysis of gene expression in several models, translation analysis using ribosome profiling (Ribo-seq) of different situations, and chromatin conformation studies of enhancer-promoter interactions using deep sequencing. The main contribution of this period is the determination, using ribosome profiling, that translation is a key regulatory step in controlling gene expression in the Chagas disease causing agent, the unicellular Trypanosome cruzi. This was done using high resolution translation quantiation for the first time in this parasite. In the same line, we are characterizing different aspects of gene expression regulation in this model. Additionally, through collaborative networks with different research groups in the country we are investigating global gene expression regulation in different models (eg, meiosis or nitrogen fixing bacteria).
Finally, several applied initiatives are being pursued with the aid of deep sequencers and genomic approaches: i) interactions with the clinical private sector to characterize genomic features in preimplantation embryos for in vitro fertilization procedures, or ii) T he detection of pathogens and metagenomics patterns from environmental samples (water).