Gene duplication and recruitment of a specific tropomyosin into striated muscle cells in the jellyfish <I>Podocoryne carnea</I> Export

@article{citeulike:5433490, abstract = {Cnidaria are the most basal animal phylum in which smooth and striated muscle cells have evolved. Since the ultrastructure of the mononucleated striated muscle is similar to that of higher animals, it is of interest to compare the striated muscle of Cnidaria at the molecular level to that of triploblastic phyla. We have used tropomyosins, a family of actin binding proteins to address this question. Throughout the animal kingdom, a great diversity of tropomyosin isoforms is found in non-muscle cells but only a few conserved tropomyosins are expressed in muscle cells. Muscle tropomyosins are all similar in length and share conserved termini. Two cnidarian tropomyosins have been described previously but neither of them is expressed in striated muscle cells. Here, we have characterized a new tropomyosin gene from the hydrozoan . Expression analysis by RT-PCR and by whole mount in situ hybridization demonstrate that is exclusively expressed in striated muscle cells of the medusa. The Tpm2 protein is shorter in length than its counterparts from higher animals and differs at both amino and carboxy termini from striated muscle isoforms of higher animals. Interestingly, Tpm2 differs considerably from Tpm1 (only 19\% identity) which was described previously in . This divergence indicates a functional separation of cytoskeletal and striated muscle tropomyosins in cnidarians. These data contribute to our understanding of the evolution of the tropomyosin gene family and demonstrate the recruitment of tropomyosin into hydrozoan striated muscles during metazoan evolution. {\copyright} 1999 Wiley-Liss, Inc.}, address = {Institute of Zoology, University of Basel, CH-4051 Basel, Switzerland; Department of Biology and Biochemistry, University of Houston, Houston, Texas 77204-5513; Biozentrum, University of Basel, CH-4056 Basel, Switzerland}, author = {Gr\"{o}ger, Hans and Callaerts, Patrick and Gehring, Walter J. and Schmid, Volker}, citeulike-article-id = {5433490}, citeulike-linkout-0 = {http://dx.doi.org/10.1002/(SICI)1097-010X(19991215)285:4%3C378::AID-JEZ5%3E3.0.CO;2-C}, citeulike-linkout-1 = {http://www3.interscience.wiley.com/cgi-bin/abstract/67501598/ABSTRACT}, doi = {10.1002/(SICI)1097-010X(19991215)285:4%3C378::AID-JEZ5%3E3.0.CO;2-C}, issn = {1552-5015}, journal = {The Journal of Experimental Zoology}, keywords = {coiled-coils, tropomyosin}, number = {4}, pages = {378--386}, posted-at = {2009-08-13 22:35:04}, priority = {2}, title = {Gene duplication and recruitment of a specific tropomyosin into striated muscle cells in the jellyfish <I>Podocoryne carnea</I>}, url = {http://dx.doi.org/10.1002/(SICI)1097-010X(19991215)285:4%3C378::AID-JEZ5%3E3.0.CO;2-C}, volume = {285}, year = {1999} }

TY - JOUR ID - citeulike:5433490 L3 - citeulike-article-id:5433490 N2 - Cnidaria are the most basal animal phylum in which smooth and striated muscle cells have evolved. Since the ultrastructure of the mononucleated striated muscle is similar to that of higher animals, it is of interest to compare the striated muscle of Cnidaria at the molecular level to that of triploblastic phyla. We have used tropomyosins, a family of actin binding proteins to address this question. Throughout the animal kingdom, a great diversity of tropomyosin isoforms is found in non-muscle cells but only a few conserved tropomyosins are expressed in muscle cells. Muscle tropomyosins are all similar in length and share conserved termini. Two cnidarian tropomyosins have been described previously but neither of them is expressed in striated muscle cells. Here, we have characterized a new tropomyosin gene from the hydrozoan . Expression analysis by RT-PCR and by whole mount in situ hybridization demonstrate that is exclusively expressed in striated muscle cells of the medusa. The Tpm2 protein is shorter in length than its counterparts from higher animals and differs at both amino and carboxy termini from striated muscle isoforms of higher animals. Interestingly, Tpm2 differs considerably from Tpm1 (only 19% identity) which was described previously in . This divergence indicates a functional separation of cytoskeletal and striated muscle tropomyosins in cnidarians. These data contribute to our understanding of the evolution of the tropomyosin gene family and demonstrate the recruitment of tropomyosin into hydrozoan striated muscles during metazoan evolution. © 1999 Wiley-Liss, Inc. IS - 4 JF - The Journal of Experimental Zoology SN - 1552-5015 AD - Institute of Zoology, University of Basel, CH-4051 Basel, Switzerland; Department of Biology and Biochemistry, University of Houston, Houston, Texas 77204-5513; Biozentrum, University of Basel, CH-4056 Basel, Switzerland EP - 386 TI - Gene duplication and recruitment of a specific tropomyosin into striated muscle cells in the jellyfish <I>Podocoryne carnea</I> VL - 285 SP - 378 KW - coiled-coils KW - tropomyosin AU - Gröger, Hans AU - Callaerts, Patrick AU - Gehring, Walter AU - Schmid, Volker PY - 1999/// UR - http://dx.doi.org/10.1002/(SICI)1097-010X(19991215)285:4%3C378::AID-JEZ5%3E3.0.CO;2-C ER -