Günter Plickert

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Metamorphosin A (MMA) isolated from the anthozoan Anthopleura elegantissima has recently been shown to interfere with developmental control in the colonial hydroid Hydractinia echinata. In order to identify the functional homologue in this species we have cloned cDNAs of the precursor protein from Hydractinia and, for comparison, precursor sequences from(More)
Wnt/Frizzled/ss-catenin-based signaling systems play diverse roles in metazoan development, being involved not only in the establishment of body axes in embryogenesis but also in regulating stem cell fate in mammalian post-embryonic development. We have studied the role the canonical Wnt cascade plays in stem cell fate determination in Hydractinia, a member(More)
We have studied the role the canonical Wnt pathway plays in hydroid pattern formation during embryonic development and metamorphosis. Transcripts of Wnt and Tcf were asymmetrically deposited in the oocyte and subsequent developmental stages, marking the sites of first cleavage, posterior larval pole and the upcoming head of the metamorphosed polyp. To(More)
Peptides of the RFamide family occur in neurosecretory cells of all nervous systems of Cnidaria so far studied. Photoreceptive organs – if evolved in a cnidarian species – are always associated with neural cells showing RFamide immunoreactivity. Experimental evidence for the function of RFamides and other neuropeptides in nervous systems and photoreceptive(More)
Hydractinia, a representative marine colonial hydroid, was the first organism in the history of biology in which migratory precursors of germ cells were described and termed "stem cells" (Weismann, 1883). These stem cells, now known as interstitial cells (i-cells), are thought to remain pluripotent throughout their life. Using animals depleted of their own(More)
The evolutionary origin of stem cell pluripotency is an unresolved question. In mammals, pluripotency is limited to early embryos and is induced and maintained by a small number of key transcription factors, of which the POU domain protein Oct4 is considered central. Clonal invertebrates, by contrast, possess pluripotent stem cells throughout their life,(More)
Peptides are increasingly attracting attention as primary signals in the control of development. Even though a large number of peptides have been characterized in cnidarians, little experimental evidence addresses their endogenous role. The life cycle of Hydractinia echinata includes metamorphosis from planula larva into the adult stage of the polyp. This(More)
 In order to facilitate in situ detection of biomolecules in large sample series the processing of whole-mount specimens has been automated. A freely programmable liquid handling system is described by which embryos or similar biological materials are processed. Possible applications include in situ hybridization (ISH), immunocytochemistry (ICC) or reporter(More)
To analyse cell migration and the differentiation potential of migratory stem cells in Hydractinia, we generated animals with an eGFP reporter gene stably expressed and transmitted via the germline. The transgene was placed under the control of two different actin promoters and the promoter of elongation factor-1α. One actin promoter (Act-II) and the EF-1α(More)
Astacin-like metalloproteases are ubiquitous in the animal kingdom but their phylogenetic relationships and ancient functions within the Metazoa are unclear. We have cloned and characterized four astacin-like cDNAs from the marine hydroid Hydractinia echinata and performed a database search for related genes in the draft genome sequence of the sea anemone(More)