Max Planck Institutes and Experts

When chromosomes mis-segregate during cell division, cells lose their balance. The resulting cells are aneuploid, they contain fewer or more chromosomes than usual. Aneuploidy is generally harmful for the cell and characteristic for pathological conditions such as Down syndrome or cancer. Scientists are currently investigating why aneuploidy is so harmful. Presumably, an imbalance of proteins present in aneuploid cells plays an important role in the process. Nevertheless, many questions regarding the origin of aneuploidy and its consequences still remain unanswered.

A reduced caloric intake increases life expectancy in many species. But how diet prolongs the lives of model organisms such as fruit flies and roundworms has remained a mystery until recently. Scientists at the institute discovered that hormone receptors are one of the links between nutrition and life expectancy in roundworms. It may be possible that related receptors are also responsible for regulating life expectancy in human beings.

Our heart pumps blood through an interconnected network of tubules to all parts of our body. This is important for the optimal availability of oxygen to every organ. How does the vasculature ensure the optimal connectivity between blood vessels? Scientists from the Max Planck Institute for Molecular Biomedicine show that differences in blood flow can control the proper sprouting and pruning of blood vessels. These discoveries could provide answers to the question why in certain disease settings, blood is not delivered efficiently.

In eukaryotic cells DNA and transcription of RNAs are separated from protein biosynthesis occurring in the cytoplasm. Nucleus and cytoplasm are only connected via the nuclear pores. Transport between the compartments is aided by dedicated shuttling proteins, the karyopherins. Most karyopherins carry cargo only in one direction, either into (importins) or out of the nucleus (exportins), and then return empty handed. Importin 13 is an unusual karyopherin that can both import and export cargo. Our work revealed how Imp13 recognizes its cargoes and functions as a bidirectional transport factor.

Planarians are known as masters of regeneration: they can re-build any part of their body after amputation. This ability relies on a large amount of pluripotent stem cells. To further investigate the mechanisms of how planarians maintain their stem cell pool over generations, scientists have now established a method for analyzing the composition of planarian stem cells and the turnover of their proteins. They discovered a protein that is not only required for the maintenance of the stem cell pool in planarians, but which might also be active in the pluripotent stem cells of mammals.