PhD Students Day III

Searching for Universal Peptide Biomarkers in Planetary Exploration

Rita Severino (Molecular Evolution Dpt. CAB)

In order to search for signs of life on other planets of the Solar System, our hypothesis assume an universal terrestrial-like biochemistry, from which proteins or proto-proteins should have be present since the beginning. In particular, our hypothesis considers that Earth and Mars shared similar habitable environments in their early histories and, perhaps, interchange of life occurred during the Late Heavy Bombardment period. To search for peptide biomarkers, we use antibody microarray technology, given that antibodies bind peptides in a highly specific manner. Using ancestral protein resurrection, metaproteomics, and antibody microarrays, my goal is to identify peptide biomarkers, conserved throughout evolution, present in a variety of different protein, and test them in an early Earth and Early Mars analog environments. By targeting well-preserved peptide sequences, identified in ancestral proteins, with different functions, and architectures, we constrain the peptide biomarker space of sequences to search for. Using this methodology, we identified peptide analogs to two hypothetical ancestral proteins, aged from three to four billion-years old, in El Tatio hydrothermal system, an ancient Mars analog.  

The lithium-rotation connection in open clusters

Diego Cuenda (Astrophysics Dpt. CAB)

Lithium is a fragile element and it is destroyed over time at the base of the convective envelope of stars like the Sun. As a consequence, lithium abundance is an age indicator for G and K spectral types, but the influence of rotation in this process is not completely characterized. Open clusters, which are associations of stars formed from the same molecular cloud, constitute an optimal scenario for studying this connection since their members are all the same age. In this talk I will briefly explain my PhD thesis project which aims at characterizing the lithium-rotation link in open clusters of different ages and to improve this technique as an age chronometer.

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