RESEARCH INTERESTS

Rodrigo GONZALEZ-ROMERO

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BACKGROUND

Rodrigo Gonzalez-Romero is a Ph. D. student in the Department of Cellular and Molecular Biology. He received his B.S. in Biology in 2005 (with Honors in 2007) at the University of A Coruna. He is doing doctoral work as a researcher in the XENOMAR group within the Genetics Area at the University of A Coruna. His research line focuses on the molecular evolutionary mechanisms underlying the differentiation and diversification of the members of the histone multigene family (chromatin-associated proteins) in mollusc organisms, as well as the use of histone proteins as genotoxicity biomarkers.

RESEARCH FOCUS

Long-term evolution of genes encoding histone proteins

Histones constitute a group of small basic proteins involved in the packaging of DNA in the eukaryotic nucleus and, subsequently, also in the regulation of gene expression. There are five histone families which can be classified in two major groups according to structural and functional features: core histones (H2A, H2B, H3 and H4 families) and linker histones (H1 family). The former organize DNA into nucleosome core particles (which constitute the basic chromatin subunit) and the latter bind to the regions contacting adjacent nucleosomes in the chromatin fiber. From an evolutionary point of view, histones represent highly conserved proteins with critical roles and their long-term evolution has been classically explained by a concerted evolution model, responsible for the homogenization of the family members through interlocus recombination or gene conversion. However, a high degree of variation and diversification in histone genes have been demonstrated during the last 10 years, suggesting the birth-and-death model as the major mechanism guiding histone evolution. We are studying the relative importance of the different evolutionary pathways followed by different types of histones, showing that the birth-and-death mechanism of evolution is the major process responsible for histone diversification/differentiation, instead of a classical concerted evolution process. 

Histone proteins as genotoxicity biomarkers

Histone variants are used by the cell to build specialized nucleosomes, replacing canonical histones at different stages of the cell cycle and generating an architecturally and functionally distinct chromatin structure. The exchange of canonical histones for certain histone variants can be related with defined cellular responses to diverse toxic components which may represents an useful and novel marker of toxicity. In this regard, we are interested in the study of the histone variants H2A.X (directly involved in the quick response to double strand breaks in DNA) and H1.2 (involved in the release of apoptotic factors from mitochondria) in lower invertebrates, specially bivalve molluscs, given the exposure of these organisms to natural (i.e., red tides) and antropogenic (i.e., fuel spills) pollutants. The characterization of genotoxicity biomarkers in marine organisms relevant for food industry represents a very important objective, both for conservation biology as well as to analyze the possible effects of the consumption of these contaminated specimens on human health.