Judith Reichmann, of the Ellenberg group at EMBL Heidelberg, will receive this year’s Paul Ehrlich and Ludwig Darmstaedter Prize for Young Researchers. The prize, awarded by the Paul Ehrlich Foundation, is given to scientists from all over the world who have achieved outstanding results in biomedical research – the field of work of Paul Ehrlich, a Nobel Prize-winning German doctor and serologist. The Prize is one of Germany’s highest scientific accolades. Following tradition, the prize-giving ceremony will be held on 14 March, Paul Ehrlich’s birthday.
Reichmann has shown why mouse embryos sometimes have the wrong number of chromosomes, or have more than one nucleus per cell. Her findings in mice on the sources of errors in the formation of egg and sperm cells, and during the first cell division after fertilisation, are also of interest for improving human fertility treatments.
She was able to show that the protein Tex19.1 in mice monitors the protracted and error-prone halving of the chromosome set during the formation of egg and sperm cells, and ensures that the correct number of chromosomes is passed on to the offspring. If the function of this protein is disturbed or missing completely, many embryos among the offspring will have the wrong number of chromosomes.
Reichmann was also able to show that paternal and maternal chromosome sets are distributed to the two daughter cells via two separate spindles during the first cell division after fertilisation, instead of via a common spindle as previously assumed. As a result, the maternal and paternal chromosomes remain separate during the first cell division and do not mix until subsequent divisions. The formation of two separate spindles could also explain part of the high error rate in cell divisions in the early embryo. However, it is not yet known whether the same is true in humans.
Video revealing how the two parental genomes (labelled in pink and blue) remain spatially separate throughout the first cell division.