We have more than one Genome

Inspired by a recently published article in the ZEIT (in German only), I did some further reads on the topic of mosaicism. The bottom line: contrary to common belief and what is taught in text books (and University courses), the human body does not consist of cells with a single, personal genome, but instead each cell or cell-cluster has it’s own personal genome. A phenomenon that is also called “mosaicism”.

Until recently we needed a bunch of cells that were used to sequence our DNA, but today we are able to look on our genes on a single-cell basis. Findings now reveal a new theory on how our cells and tissue has evolved and allows for new theories on somatic and psychiatric illnesses.

From a review by Biesecker and Spinner (2013)1:

It has long been known that cancer is a mosaic genetic disorder, but mosaicism is now apparent in a diverse range of other clinical disorders, as indicated by their tissue distributions and inheritance patterns. Recent technical advances have uncovered the causative mosaic variant underlying many of these conditions and have provided insight into the pervasiveness of mosaicism in normal individuals.

This not only changes how we should think about the genetic basis of diseases but also about the genetic basis for personality and “normal” human behavior.

From this findings new theories of genetics and the genetic causes of human differences and diseases will emerge. We are not a single piece of cells with a pre-determined DNA, but a bunch of cells with different and still ongoing mutations in a DNA, that begun with only a single cell. This is fascinating and shows the ever-evolving nature of science and that we have by no means already “discovered everything that can be discovered”.

Further reads

Quartz: A tumor stole every memory I had.

Not directly related to my field of research, but a very interesting story from a patient who lost memories due to a craniopharyngioma and gains them back as the tumor is removed:

What eventually did happen was something none of the experts ever suggested would be possible. Over time I would lose my memory—almost completely—of things that happened just moments before, and become unable to recall events that happened days and years earlier. To the rest of the world, I would become a young man behaving bizarrely, perhaps drunkenly, and I lacked the ability to acknowledge it, or fully explain what was going on. As it grew, eventually to the size of a small egg, the tumor dug a hole in my consciousness, of ever-increasing depth. I became incapable of living the life I had made for myself.

– Source: Quartz

It’s quite a long read but you might want to save it later for your next afternoon or weekend read.

Re: Blog

Okay, schon wieder ein Blog. Ja, ich habe in den letzten Jahren immer wieder neue Blogs aufgemacht. Und ja, die haben selten länger als ein Jahr gehalten. Trotzdem habe ich noch mal einen neuen Anlauf gestartet.

Und wieso? Seit Anfang Oktober arbeite und promoviere ich in der Abteilung Methodenlehre, Diagnostik und Evaluation an der Uni Bonn. Das führt dazu, dass ich häufiger mal interessante Paper lese und da irgendwie meinen Senf zu abgeben möchte. In dieser Hinsicht richtet sich der Blog also an Interessierte jeglicher Herkunft und Fachrichtung.

Damit das alles aber nicht zu langweilig wird, könnten hier – bitte nicht erschrecken – auch mal Fotos oder ähnliches auftauchen. Und um die Komplexität Internationalität zu steigern, werden einige Posts sicherlich auch mal auf Englisch kommen.

Keine Ahnung, ob das jetzt länger als ein Jahr klappt, aber ich dachte mir: Ich versuch’s einfach mal wieder.