March 13, 2012Mechanism for a self-incompatibility system to avoid self-fertilization
Dr. Takako Saito, Prof. Hitoshi Sawada and Assistant Prof. Lixy Yamada at Sugashima Marine Biological Laboratory, Nagoya University revealed a mechanism of self-incompatibility (SI) system in the ascidian Ciona intestinalis in collaboration with Prof. Kazuo Inaba and Assistant Prof. Kogiku Shiba at Shimoda Marine Research Center, University of Tsukuba. Many hermaphroditic organisms including ascidians have a SI system to avoid self-fertilization. Real-time Ca2+ imaging showed that Ca2+ increase in the sperm triggered by binding to self-egg coat led to the termination of flagellar movement and sperm detachment from the egg coat. These results suggest that s-Themis-B, one of genes responsible for self-sterility and encoding Ca2+ channel identified by Prof. Sawada and his colleagues, may function in rejecting self-fertilization via Ca2+ signals. Plants have similar molecular mechanism for SI system and Ca2+ signaling as ascidians. These findings will shed light on the common mechanism of SI system in plants and animals and can also be applied to many reproductive technologies. These results were published in Proceedings of the National Academy of Sciences of the United States of America (PNAS) on March 13, 2012. .
http://www.ncbi.nlm.nih.gov/pubmed/22357759
February 10, 2011 
An international research group including Assistant Professor Hiroaki Nakano at Shimoda Marine Research Center, University of Tsukuba, Professor Maximilian Telford at University College London, and other colleagues has shown that the marine invertebrate worms Acoelmorpha and Xenoturbella form a sister group within the deuterostomes. Although there are about 30 animal phyla known today, only three have been regarded as deuterostomes: hemichordates, echinoderms, and chordates, to which we humans belong. 'Xenacoelomorpha', consisting of Acoelmorpha and Xenoturbella, is the fourth living phylum of deuterostomes and further research on Xenacoelomorpha shall provide new insights into the evolution of deuterostomes. These results were published in Nature on February 10th, 2011.
January 3, 2011Drs. Takeo Horie, Yasunori Sasakura and their colleagues at the Shimoda Marine Research Center, University of Tsukuba published a manuscript entitled "Ependymal cells of chordate larvae are stem-like cells that form the adult nervous system" in the journal Nature in collaboration with Dr. Takehiro G. Kusakabe at the Konan University and Dr. Nori Satoh at the Okinawa Institute of Science and Technologies. This manuscript describes transition of the central nervous system during metamorphosis of urochordate ascidian. They showed that larval ependymal cells are the major cells constructing the adult nervous system and some of them are neural stem-like cells that produce adult neurons. These results were published in Nature.
December 17, 2010"Isolation of a novel lectin from feather star with an unique glycan-binding profile"
A novel lectin (glycan-binding protein) has been purified from feather star Oxycomanthus japonicus (Permatozoa: Crinoidea) by Prof. Yasuhiro Ozeki (Graduate School of Yokohama City University), Dr S.M. Abe Kawsar (JSPS Postdoctoral Research fellow), Dr Tomoko F. Shibata (Postdoctoral Research fellow, Department of Biology, University of Miami), technical support division of Misaki Marine Biological Station (Graduate School of the University of Tokyo, Prof. Koji Akasaka, Director) and Yokohama Science Frontier High school (Yokohama City, Japan, Mr. Haruo Sato, Principal) through the support with National BioResource Project (NBRP) MEXT Japan. Glycan-binding specificity of the lectin has been profiled as it recognized only oligosaccharides with type-2 N-acetyllactosamine structure by a glycomics approach using frontal affinity chromatography technology. An uniqueness of the glycan-binding specificity was expected to apply the lectin for the study on regulation of cell differentiation and novel diagnostics. It has been published as a research article as Matsumoto et al., Comparative Biochemistry and Physiology B 158, 266-273 (2011) doi:10.1016/j.cbpb.2010.12.004.
http://www.ncbi.nlm.nih.gov/pubmed/21176791
August 23, 2010
A research group of Professor Masumi Nozaki at Sado Marine Biological Station, Niigata University has identified the first and perhaps only gonadotropin (GTH) from the pituitary of the hagfish Paramyxine atami. The hagfish GTH consists of two subunits, α and β, which are synthesized and colocalized in the same cells of the adenohypophysis. The cellular and transcriptional activities of hagfish GTHα and β were significantly correlated with the developmental stages of the gonad. The purified native GTH induced the release of gonadal sex steroids in vitro. It is suggested that the identity of a single functional GTH of the hagfish provides critical evidence for the existence of a pituitary-gonadal system in the earliest divergent vertebrate that likely evolved from an ancestral, pre-vertebrate exclusively neuroendocrine mechanism by gradual emergence of a new control level, the pituitary, that is not found in the Protochordates. These results were published in Proceedings of the National Academy of Sciences of the United States of America (PNAS) on August 23, 2011.