picture modified from Goldstein Lab via flickr

Wer letztens Zeitung gelesen hat, konnte es kaum verpassen: die Süddeutsche Zeitung hat darüber geschrieben, aber auch die Zeit, der Standard, die Welt, tagesschau.de und sogar die Bild Zeitung: auf dem Mond soll es nun Leben geben! Die Fragen: seit wann? woher? und welcher Art? sind dabei leicht zu beantworten: seit April 2019, von der Erde und es handelt sich um Bärtierchen, auch Wasserbären oder Tardigraden genannt. Ich erinnere mich noch gut an mein Biologiestudium: Bärtierchen waren damals ein highlight! Seit meiner Spezialisierung auf molekulare Medizin, Entwicklungsbiologie und Genetik hatte ich dann aber leider nichts mehr mit diesen niedlichen mikroskopisch kleinen Kreaturen zu tun. Deshalb hab‘ ich mich umso mehr gefreut, innerhalb der letzten paar Jahre vermehrt Artikel zu Bärtierchen zu finden. Dabei war vor allem ihre unglaubliche Widerstandsfähigkeit gegenüber Strahlung von Interesse. Und diese Superkraft wird Bärtierchen vor allem durch das dieswöchige Gen Dsup, damage suppressor protein, verliehen. Achtung: das dsup Gen sollte dabei nicht mit dem sup Gen verwechselt werden. Denn sup codiert das SUPERMAN Gen der Acker-Schmalwand, dem wohl wichtigsten pflanzlichen Modellorganismus (aber dazu vielleicht irgendwann einmal mehr in einem anderen Artikel).

We have reached a stage where the amount of studies that describe the function of a particular gene in a particular model organism and under particular conditions has become unmanageable. At the same time, articles that describe a completely new cellular mechanism that may occur in all animal and plant cells, but has remained hidden so far, became extremely rare. That's why the two articles that appeared in the journal Nature last week are so special. And to understand what makes them special, we need to have a closer look on a paradoxical observation in the field of genetics that has become more prevalent over the last few years.

Genetic engineering methods such as CRISPR nowadays allow the targeted mutation of a gene, so that the function of the encoded protein is completely lost. This is called a genetic knock-out. Other methods, such as the use of RNA interference, allow the downregulation of gene function by blocking the mRNA transcript of the corresponding gene or initiate their degradation. As a result, the translation of these mRNA molecules is disturbed, so that much less of the corresponding protein is formed. However, a few functional molecules remain, which is why we call those methods knock-down procedures. Absurdly, however, it was repeatedly observed that these knock-down approaches lead to a stronger effect than the previously mentioned knock-out approaches, which nevertheless lead to a complete loss of the protein under investigation. How is that possible? This remained a mystery for quite some time…

Well, actually there are two BRCA (pronounced "Brakka") genes: BRCA1 and BRCA2. Few genes have caused so many headlines in recent years as they did. The BRCA genes are so hotly debated as an American biotech company was holding an extremely lucrative patent on these two genes. What that means I would like to explain later; but first, why are BRCA1 and 2 so important?

Virus: CowpeaMosaicVirus3D by Thomas Splettstoesser for wikimedia.org, CC-BY-SA-3.0

The year 2018 is about to end and it was yet another extremely eventful year for molecular biology and biomedicine. CRISPR has captured the headlines around the globe. But not every piece of research that has caused a sensation and astonishment this year has been directly related to CRISPR. As early as January 2018, two articles were published in the same issue of the journal Cell, which was jaw-dropping for several members of our working group, including myself. Back then - due to an acute lack of time - I did not manage to explain why these two articles had such an effect. Anyway, here finally is the long overdue article on the ARC gene and the question about whether an evolutionarily ancient virus(!), could be responsible for us being able to remember things so well.