Researchers' portraits

Conrad Hal Waddington

• * born Nov. 8, 1905 Eversham, England
• 1926 Graduated in geology at Sidney Sussex College Cambridge
• From 1926 Studied philosophy, modern art and Morris dancing; studied Hans Spemann's research on amphibious embryos
• 1930 Specialized in embryology
• 1935 Cambridge ScD (Doctor of Science)
• 1936 Fellow of Christ's College Cambridge
• 1936 Albert Brachet Prize in embryology
• 1947 Professor and head of the Institute for Animal Genetics at the University of Edinburgh
• 1957 Published the essay on The Strategy of the Genes
• † 26.09.1975 Edinburgh, Scotland

Epigenetic landscape

Illustration: Epigenetic landscape as original
Source: Website Dave Tang

Waddington's original definition of epigenesis referred to changes during cell differentiation and the way in which the ability of cells to transform becomes limited with time. He was particularly interested in the stabilization of stages during the development process. To illustrate these processes, he used the metaphor of the epigenetic landscape and presented it in a model: The cell – represented by a ball – rolls through valleys of a hilly landscape and strives to reach the point of minimal energy expenditure. Waddington described how these developmental paths are influenced by genes but are also characterized by environmental factors. Because of the valley walls between the individual paths, the course cannot be easily changed. However, induction from outside can be strong enough to overcome a valley flank in the epigenetic landscape (large jump). The ball then enters an adjacent valley, development is channeled differently. The concept remains valid until today, even though epigenetics has changed its definition and today refers to various regulatory options that can influence the activity of genes independently of the DNA sequence.

Illustration: Landscape of development, differentiation and reprogramming: Four germ layers, trophectoderm, ectoderm, mesoderm and endoderm, in which cells mainly develop, are shown. Transitions (jumps) when cells change into cells of another cotyledon or put into the "initial state" (reprogramming) are difficult to achieve. Source: EuroStemCell: Cell replacement therapies: iPS technology or transdifferentiation?

Search terms: Epigenetic landscape, channeling, buffering and genetic assimilation, EvoDevo-Research (evolution and development)

Emmanuelle Charpentier

Director at the Max Planck Institute for Infection Biology Berlin, honorary professor at the Institute of Biology at the Humboldt University in Berlin, Research Group Leader and guest professor at the University of Umeå, Sweden, Alexander von Humboldt

Emmanuelle Charpentier
Source: Hallbauer & Fioretti/Wikimedia

• born Dec. 11,1968 Juvisy-sur-Orge, France
• 1986-1992 Studied biology, microbiology, biochemistry and genetics at University Pierre et Marie Curie, Paris (UPMC)
• 1992-1997 Doctoral student at Pasteur Institute, post-doctoral student at Pasteur Institute and Rockefeller University, New York
• 1997-1999 Assistant Research Scientist at New York University Medical Center
• 1999-2002 Research Associate at St. Jude Children‘s Research Hospital, Memphis and at the Skirball Institute of Biomolecular Medicine, New York
• 2002-2004 Research Group Leader and visiting professor at the Institute of Microbiology and Genetics, University of Vienna
• 2004-2006 Research Group Leader and Assistant Professor, University of Vienna
• 2006 Senior Lecturer for microbiology and habilitation at the Centre for Molecular Biology, University of Vienna
• 2006-2009 Research Group Leader and Associate Professor at Max F. Perutz Laboratories, Vienna
• 2009-2014 Research Group Leader and Associate Professor at the Laboratory for Molecular Infection Medicine Sweden (MIMS), University of Umeå, Sweden
• 2013 Lecturer in Medical Microbiology, University of Umeå
• 2013-2015 Head of Department at the Helmholtz Center for Infection Research, Braunschweig and W3 professor at Hannover Medical School
• seit 2015: Director at the Max Planck Institute for Infection Biology Berlin

The article A Programmable Dual-RNA-Guided DNA Endonuclease in Adaptive Bacterial Immunity was published in 2012. On five pages, the authors Emmanuelle Charpentier and Jennifer Doudna describe the defense system of the scarlet fever bacterium Streptococcus pyogenes: it uses a molecule-sized instrument that consists of a viewfinder and a kind of DNA scissor. The acronym for this defense system is CRISPR/Cas9, generally abbreviated to: CRISPR [pronounced: kris :: per]. The gene scissors of the streptococcal bacterium can be reconstructed, and its viewfinder set on any targets of the DNA sequence.