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LLUÍS MONTOLIU AN. R. ACAD. NAC. FARM.

Palabras clave: Células troncales embrionarias.—Ratones mutantes.—Blasto-
cistos.—Recombinación homóloga.—Genómica funcional.

SUMMARY

Gene targeting in mice awarded with the 2007 Nobel Prize in Physiology
or Medicine

The Nobel Prize in Physiology or Medicine for 2007 has been awarded jointly,
well deserved, to the American scientists Mario Capecchi and Oliver Smithies,
and to the British scientist Sir Martin Evans, for their pioneer contributions and
experimental design resulting in the obtention of the first knockout mice with a
gene targeted event, with the specific inactivation of a gene, leaving the rest of the
genome intact. Martin Evans described, in 1981, the extraordinary plasticity of
pluripotent embryonic stem cells, from the inner cell mass of the blastocyst, thus
allowing their maintenance in culture indefinitely, their genetic manipulation and,
eventually, their reintroduction in a new blastocyst, without loosing their capacity
to differentiate to any of the cellular types found in an adult organism, including
the germ line. Mario Capecchi explored, in the 80s, the strategies that allowed him
to selectively alter a given genetic sequence, using the homologous recombination
procedure, and established, in 1988, the general method of positive-negative double
selection. Finally, Oliver Smithies, in 1989, modified a first gene (inactivated) in
embryonic stem cells in culture, later obtained a chimera and eventually, through
a number of crosses, an animal that, in all of its cells, was carrying the initial
mutation of the selected gene.

Keywords: Embryonic stem cells.—Knockout mice.—Blastocysts.—Homologous
recombination.—Functional genomics.

EL PREMIO NOBEL DE FISIOLOGÍA O MEDICINA DE 2007

El 8 de octubre de 2007, la Asamblea Nobel del Instituto Karolins-
ka (Estocolmo, Suecia) anunció su decisión de otorgar el premio
Nobel de Fisiología o Medicina de 2007 a tres destacados científicos,
de forma conjunta. Los científicos premiados, merecidamente, fueron
Mario Capecchi, Martin J. Evans y Oliver Smithies por sus logros y
descubrimientos de «los principios para la incorporación de modifi-
caciones genéticas específicas en ratones mediante el uso de células
troncales embrionarias» (Figura 1). Pocas veces un premio Nobel de
Medicina ha sido tan celebrado, a la par que esperado desde hace
tiempo, por la comunidad de investigadores en biomedicina como en

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