Max Planck Institutes and Experts

Faithful distribution of the genetic material during cell division relies on the folding of DNA into discrete and compact bodies called chromatids. SMC protein complexes have evolved to deal with the tangly nature of long DNA molecules. They act as molecular clamps that bring together selected DNA segments. The researchers determined the architecture of the ancestral SMC complex and elucidated its dynamic localization on the bacterial chromosome. The results indicate that SMC rings are not merely DNA linkers but active machines, which step-by-step enlarge DNA loops to organize chromosomes.

Haploid gametes are produced in meiosis, a special form of cell division where DNA replication is followed by two rounds of chromosome segregation and gametogenesis. Homologous chromosomes segregate in meiosis I, whereas chromatids disjoin in meiosis II. Scientists of the research group Chromosome Biology now revealed how the conserved Hrr25 kinase of yeast coordinates production and packaging into gametes of the single-copy genome in meiosis II.

Ageing is not a random process. Biological ageing processes are instead regulated by metabolic and genetic mechanisms. Single gene mutations can markedly extend the life span of various organisms. The biology of ageing can be investigated in simple yeast cells, flies, round worms, and also in mice. Gene mutations that extend life span also protect against age-associated diseases such as neurodegeneration, cancer, heart disease, and diabetes. A deeper understanding of molecular mechanisms of longevity can open new avenues for therapies or prevention of these highly relevant diseases.

Pluripotent stem cells represent an amazing tool box for generating virtually any cell tissue of the human body such as, for instance, spontaneously beating cardiac muscle tissue. How this actually works and how the process can be controlled better was recently revealed. Two regulatory switches inside the cells need to be manipulated at the right time. This surprisingly simple procedure may be used for studying the mechanisms underlying genetic cardiac disorders and for evaluating putative drugs.

Connectomes are wiring diagrams of neural networks showing the specific connections between neurons. The research group Neurobiology of marine zooplankton is working on the complete wiring diagram of a small marine larva to understand how neuronal circuits mediate behaviour.