In memory of Juan Modolell Mainou

Last February 28th, Juan Modolell Mainou passed away in Madrid at the age of 85 due to a prostate tumor. Juan was an ad honorem CSIC Research Professor at the Centro de Biología Molecular Severo Ochoa (CBMSO), he started his research career at the Centro de Investigaciones Biológicas (CIB-CSIC), and is considered a pioneer and international reference in molecular and developmental biology.

Born in Barcelona in 1937, Juan obtained a degree in Biological Sciences from the University of Barcelona (1959), and in Chemical Sciences from the University of La Laguna (1962), followed by a Ph.D. in Biochemistry from Ohio State University in the United States (1966) and in Chemical Sciences from the Complutense University of Madrid (1971). In 1970 he began his research activity at the CSIC, joining the Institute of Cell Biology, at that time belonging to the CIB, located at 144 Velázquez Street in Madrid. There, he initiated studies on the mechanisms involved in protein synthesis using the bacterial model of Escherichia coli, including the interaction of the ribosome with the elongation factors EFG and EFT, and with aminoacyl-tRNA, as well as the stoichiometry of polypeptide chain elongation and the associated peptidyl-transferase and GTPase activities. Within David Vázquez's group, and together with the researchers Juan Pedro García Ballesta and Antonio Jiménez, he studied the mechanisms by which various antibiotics interact with the ribosome inhibiting protein synthesis and therefore bacterial proliferation. Thus, he was able to elucidate the inhibitory mechanism of the antibiotics streptomycin, neomycin, hygromycin, siomycin, fusidic acid, thiostrepton, and viomycin, among others.

In 1975 he left the CIB to move to the CBMSO at the campus of the Universidad Autónoma de Madrid, where he continued his research on the mechanisms of protein biosynthesis. In 1980, he set himself new scientific challenges and left the study of the bacterial ribosome to learn new techniques of genetic manipulation. With this objective in mind, he made a stay in Matt Messelson's laboratory (Harvard University, USA), and on his return to Madrid, he began to work on genes involved in the development and morphogenesis of the vinegar fly, Drosophila melanogaster. His conversations with Antonio García-Bellido, who, together with Ginés Morata, was a national pioneer in the field of genetics and developmental biology, were of special relevance in this turn of his career.

In his renovated laboratory at the CSIC, he worked together with his loyal and efficient collaborator Sonsoles Campuzano and with José Luis Gomez Skarmeta, his brilliant disciple who recently passed away, among other collaborators. The result of his research work is reflected in important scientific achievements such as: (i) molecular and functional characterization of the proneural genes of the achaete-scute complex (C-AS) and of its regulator extramacrochaetae; (ii) description of the genes of the iroquois complex and analysis of their function in the neural pre-pattern and in the specification of thorax and head; (iii) functional characterization of the charlatan, echinoid, msh and tail-up genes; (iv) physical mapping and sequencing of the Drosophila genome; and (v) identification and characterization of the Xiro genes, homologues of the iroquois complex genes in Xenopus.

The relevance of his scientific achievements led him to receive numerous awards throughout his career, including those of the Spanish Royal Academy of Exact, Physical and Natural Sciences (1993), the Carmen and Severo Ochoa Foundation (1994), the Narcís Monturiol Medal of the Generalitat de Catalunya (1996), the DuPont of Science (2000), the Rey Jaime I for Scientific Research (2002), and the Santiago Ramón y Cajal National Research Award (2006).

In addition to his successful career as a researcher, Juan Modolell will also be remembered for being a good person, kind and polite, and for his role as a teacher of many scientists who currently make up his school in various national and international research centers.

Written by Prof. Carmelo Bernabeu