Bio

Professional Education


  • Diplom, Rheinische Friedrich-Wilhelms-Univ (2008)
  • Doctor, Rheinische Friedrich-Wilhelms-Univ (2012)

Stanford Advisors


Publications

All Publications


  • A K(+)-selective CNG channel orchestrates Ca(2+) signalling in zebrafish sperm. eLife Fechner, S., Alvarez, L., Bönigk, W., Müller, A., Berger, T. K., Pascal, R., Trötschel, C., Poetsch, A., Stölting, G., Siegfried, K. R., Kremmer, E., Seifert, R., Kaupp, U. B. 2015; 4

    Abstract

    Calcium in the flagellum controls sperm navigation. In sperm of marine invertebrates and mammals, Ca(2+) signalling has been intensely studied, whereas for fish little is known. In sea urchin sperm, a cyclic nucleotide-gated K(+) channel (CNGK) mediates a cGMP-induced hyperpolarization that evokes Ca(2+) influx. Here, we identify in sperm of the freshwater fish Danio rerio a novel CNGK family member featuring non-canonical properties. It is located in the sperm head rather than the flagellum and is controlled by intracellular pH, but not cyclic nucleotides. Alkalization hyperpolarizes sperm and produces Ca(2+) entry. Ca(2+) induces spinning-like swimming, different from swimming of sperm from other species. The "spinning" mode probably guides sperm into the micropyle, a narrow entrance on the surface of fish eggs. A picture is emerging of sperm channel orthologues that employ different activation mechanisms and serve different functions. The channel inventories probably reflect adaptations to species-specific challenges during fertilization.

    View details for DOI 10.7554/eLife.07624

    View details for PubMedID 26650356

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