Cloning, characterization and chromosomal localization of a repeated sequence in Crypthecodinium cohnii, a marine dinoflagellate Autores/as Hervé Moreau Observatoire Océanologique de Banyuls, Laboratoire Arago, Banyuls-sur-Mer, France Marie-Line Géraud Observatoire Océanologique de Banyuls, Laboratoire Arago, Banyuls-sur-Mer, France Yvonne Bhaud Observatoire Océanologique de Banyuls, Laboratoire Arago, Banyuls-sur-Mer, France Marie-Odile Soyer-Gobillard Observatoire Océanologique de Banyuls, Laboratoire Arago, Banyuls-sur-Mer, France Palabras clave: Crypthecodinium cohnii, repeated sequence, dinoflagellates, chromosomal localization, genomic organization Resumen Genomic DNA of Crypthecodinium cohnii has been extracted in the presence of cetylmethylammonium bromide and hydrolysed by 13 restriction enzymes. No typical ladder-like pattern or isolated band of satellite sequences were found with any of these enzymes. A “mini” genomic DNA library had been made and screened by reverse hybridization to isolate highly repeated sequences. Seven such DNA fragments were sequenced. The copy number of one of them (Cc18), 226 bp long, was estimated at around 25,000, representing 0.06% of the total genome. Cc18 was found to be included in a higher fragment of 3.0 kb by Southern blot analysis after cleavage by PstI. This higher molecular weight fragment could be composed either of tandemly repeated Cc18 sequences, or by only one or a very low copy number of Cc18. In this latter case, these fragments, also repeated 25,000 times would represent 1 to 2% of the total genome. Genomic localization of Cc18 by in situ hybridization on squashed C. cohnii cells showed that it was widely distributed on the different chromosomes. All the chromosomes observed displayed Cc18 labeling, which appeared homogeneously distributed. The ability of Cc18 to be a specific molecular marker to distinguish sibling C. cohnii species is discussed. Descargas PDF (English) Publicado 2010-03-18 Número Vol. 1 Núm. 1 (1998) Sección Research Articles Licencia Submission of a manuscript to International Microbiology implies: that the work described has not been published before, including publication in the World Wide Web (except in the form of an Abstract or as part of a published lecture, review, or thesis); that it is not under consideration for publication elsewhere; that all the coauthors have agreed to its publication. The corresponding author signs for and accepts responsability for releasing this material and will act on behalf of any and all coauthors regarding the editorial review and publication process.If an article is accepted for publication in International Microbiology, the authors (or other copyright holder) must transfer to the journal the right–not exclusive–to reproduce and distribute the article including reprints, translations, photographic reproductions, microform, electronic form (offline, online) or any other reproductions of similar nature. Nevertheless, all article in International Microbiology will be available on the Internet to any reader at no cost. The journal allows users to freely download, copy, print, distribute, search, and link to the full text of any article, provided the authorship and source of the published article is cited. The copyright owner's consent does not include copying for new works, or resale. In these cases, the specific written permission of International Microbiology must first be obtained.Authors are requested to create a link to the published article on the journal's website. The link must be accompanied by the following text: "The original publication is available on LINK at <http://www.im.microbios.org>. Please use the appropiate URL for the article in LINK. Articles disseminated via LINK are indexed, abstracted, and referenced by many abstracting and information services, bibliographic networks, subscription agencies, library networks, and consortia.