HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE ADVANCED SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Watanabe, S. Articles by Akasaka, K. Search for Related Content PubMed PubMed Citation Articles by Watanabe, S. Articles by Akasaka, K.

¹ Aminal Genome Research Unit, Division of Animal Science, National Institute of Agrobiological Sciences, Ikenodai 2, Tsukuba, Ibaraki, 305-8602, Japan
² Department of Mathematical and Life Sciences, Graduate School of Science, Hiroshima University, Kagamiyama, Higashi-Hiroshima 739-8526, Japan
³ The Institute of Medical Sciences, Tokai University, Bohseidai, Isehara, Kanagawa, 259-1193, Japan

An insulator is a DNA sequence that has both enhancer-blocking activity, through its ability to modify the influence of neighboring cis-acting elements, and a barrier function that protects a transgene from being silenced by surrounding chromatin. Previously, we isolated and characterized a 582-bp-long element from the sea urchin arylsulfatase gene (Ars). This Ars-element was effective in sea urchin and Drosophila embryos and in plant cells. To investigate Ars-element activity in mammalian cells, we placed the element between the cytomegalovirus enhancer and a luciferase (luc) expression cassette. In contrast to controls lacking the Ars-element, NIH3T3 and 293T cells transfected with the element-containing construct displayed reduced luciferase activities. The Ars-element therefore acts as an enhancer-blocking element in mammalian cells. We assessed the barrier activity of the Ars-element using vectors in which a luc expression cassette was placed between two elements. Transfection experiments demonstrated that luc activity in these vectors was approximately ten-fold higher than in vectors lacking elements. Luc activities were well maintained even after 12 weeks in culture. Our observations demonstrate that the Ars-element has also a barrier activity. These results indicated that the Ars-element act as an insulator in mammalian cells.

Present addresses: ^aFrontier Science Research Center, Kagoshima University, Korimoto 1-21-40, Kagoshima 890–0065, Japan.

^bMisaki Marine Biological Station, Graduate School of Science, University of Tokyo, 1024, Koajiro, Misaki, Miura, Kanagawa 238–0225, Japan.

^* Correspondence: E-mail: kettle{at}affrc.go.jp