Group Leader/s



Our Research Group is interested in the study of Ribosome Biogenesis in proliferating plant cells.

The name of the Group is due to the fact that this functional process is visualized in an outstanding domain of the cell nucleus, called Nucleolus; furthermore, the structural and morphological aspects that determine the in situ expression of the functional process have a prominent position among our experimental approaches.

The Nucleolus - its functional organization, its molecular architecture - is probably the best cellular model of a process of gene expression in eucaryotes, and its alterations result an excellent indicator of functional changes in the cell, especially of those changes related to cell proliferation and the cell division cycle.

These advantageous features have been used to investigate the alterations induced by the microgravity environment in the functions of plant cells. Weightlessness, existing on board od spaceships, is an unknown environment for terrestrial living beings, and may induce in them - and specifically in plants - an important stress, against which they develop countermeasures, whose cellular bases we are interested in investigating.

Christmas trees y Nucleolo


Spread transcribing plant ribosomal genes, at the electron microscope, with the shape of "Christmas trees".

(Greimers and Deltour, 1984; courtesy of Dr. R. Deltour)


Ultrathin section of the Nucleolus of Arabidopsis thaliana, at the electron microscope.

One nucleolus of Arabidopsis contains nearly one thousand ribosomal genes, together with their transcription products and the enzymatic and protein machinery necessary to build some 40 ribosomes per second.

The degree of packaging of the ribosome biosynthetic machinery in the nucelolus is extremely high; the two pictures at the right are at the same magnification (scale bar, in both cases, represents 1 µm)



Staff Scientists
Francisco Javier Medina Diaz
Malgorzata Ciska
Technical Staff
Raul Herranz Barranco
Predoctoral Students
Alicia Villacampa Calvo
Adela Villasante Fernandez


MINECO. Plan Estatal de I+D+i (Ref. ESP2015-64323-R


European Space Agency (ESA) y National Aeronautics and Space Agency (NASA) (Ref. ILSRA2009-0932/1177)


European Space Agency (ESA) (Ref. CORA-GBF-2011-009)


MINECO. Plan Nacional de I+D+i. (Ref. AYA2012-33982)


United Nations Office for Outer Space Affairs. Zero-Gravity Instrument Project (ZGIP)-United Nations Human Space Technology Initiative (UN-HSTI)


More info


Miguel Ángel Valbuena Crespo: "Interacción entre la percepción de la luz y la gravedad sobre el crecimiento y la proliferación celular en Arabidopsis thaliana: simulación en Tierra y definición del experimento espacial “Seedling Growth”. Complutense University of Madrid, Faculty of Biological Sciences. Supervisors: Raúl Herranz and Eugénie Carnero-Díaz (2016)

Khaled Youssef Kamal: “Alterations induced by gravity changes in proliferating cultured cells of Arabidopsis thaliana”. Complutense University of Madrid, Faculty of Biological Sciences. Supervisors: Raúl Herranz and F. Javier Medina (2014).

Ana Isabel Manzano Pérez: “Functional changes in proliferating cells of Arabidopsis thaliana grown in altered gravity environments”. Complutense University of Madrid, Faculty of Biological Sciences. Supervisors: Raúl Herranz and F. Javier Medina (2012).