Max Planck Institutes and Experts

Life in concentrated brines under extreme conditions of nutrition requires extreme adaptation. By molecular and functional analysis of cellular constituents of halophilic archaea it is possible to gain insight into the biology of these fascinating organisms on a systems level of the cell.

Nature hasn’t made things easy for mammals. Admittedly, as any other vertebrate – they develop from a fertilised egg, but unlike fish or frogs, the embryo cannot prosper by itself. Only if it succeeds, after having divided a couple of times, in implanting with its outer cells in the womb, its inner cells will create a foetus. It has long been unclear as to when and how the cells of an embryo pursue various lineages. Scientists of the MPI for Molecular Biomedicine in Münster have now advanced a great deal towards unravelling this mystery.

Animal embryos specify four early cell types. Determining the underlying mechanism is one central question of developmental biology. At present, it is studied how the crustacean Parhyale hawaiensis manages such developmental program at the eight-cell stage. Specification of germ cells, e.g., depends on the genes vasa and nanos, however, in a different way than in Drosophila melanogaster , demonstrating change of gene function during evolution.

MicroRNAs (miRNAs) are genome-encoded, about 22 nucleotide-long RNAs that silence gene expression post-transcriptionally by binding to 3’-untranslated regions of messenger RNAs. Although much information has been obtained about miRNA biogenesis and biological functions, the mechanisms allowing miRNAs to silence gene expression in animal cells remain controversial. Our goal is to understand the molecular mechanism of miRNA-mediated gene silencing.

The atomic structures of a bacterial succinate:quinone oxidoreductase and of mechanistically interesting variants have been determined by X-ray crystallography. Together with complementary functional studies, these results have yielded unequivocal evidence for a novel type of essential transmembrane proton transfer driving transmembrane electron transfer in this protein complex.