From owner-dros@hgmp.mrc.ac.uk Thu Oct 12 22:51:43 2000 Return-Path: Received: by mercury.hgmp.mrc.ac.uk (Postfix, from userid 110) id BAEBB17B9A; Thu, 12 Oct 2000 22:51:42 +0100 (BST) Received: by mercury.hgmp.mrc.ac.uk (Postfix, from userid 6020) id 29A7317AF6; Thu, 12 Oct 2000 22:51:40 +0100 (BST) Received: by mercury.hgmp.mrc.ac.uk (Postfix, from userid 60001) id E4AED17AA4; Thu, 12 Oct 2000 21:43:23 +0100 (BST) To: bionet-drosophila@net.bio.net From: Michael_McKeown@brown.edu (Michael McKeown) Newsgroups: bionet.drosophila Subject: Gal4 feedback loop Organization: BIOSCI/MRC Human Genome Mapping Project Resource Centre Message-ID: <39E62281.A36295CE@brown.edu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; x-mac-type="54455854"; x-mac-creator="4D4F5353" Content-Transfer-Encoding: 7bit X-Received: by mercury.hgmp.mrc.ac.uk (Postfix, from userid 6024) id 0CCBF17A65; Thu, 12 Oct 2000 21:43:20 +0100 (BST) X-Received: from vega.brown.edu (vega.services.brown.edu [128.148.19.202]) by mercury.hgmp.mrc.ac.uk (Postfix) with ESMTP id DF279415D5 for ; Thu, 12 Oct 2000 21:43:19 +0100 (BST) X-Received: from brown.edu (biomed-jww-238.biomed.brown.edu [128.148.57.238]) by vega.brown.edu (8.9.3/8.9.3) with ESMTP id QAA09396 for ; Thu, 12 Oct 2000 16:43:19 -0400 (EDT) X-Mailer: Mozilla 4.73C-CCK-MCD {C-UDP; EBM-APPLE} (Macintosh; U; PPC) X-Accept-Language: en X-To: dros@net.bio.net Date: Thu, 12 Oct 2000 22:51:40 +0100 (BST) Sender: owner-dros@hgmp.mrc.ac.uk Precedence: bulk I am interested in using a system in which an enhancer, which may be transciently on, induces the expression of Gal4 which then activates a positive feedback loop such that Gal4 continues to be expressed even after expression from the enhancer of interest has ended. Such a system, or a system based on a similar idea, allows the identification of what a particular set of cells in an imaginal disc or a the CNS becomes or contacts after differentiation. I heard multiple people talk about such systems at the CSH Drosophila Neurobiology meeting a year ago, but can find no references. If you know of such a system, or a reference, or someone who is using such a system, I would appreciate hearing about it. Thanks, Mike McKeown Molecular Biology, Cell Biology and Biochemistry G-J363 Brown University 69 Brown Street Providence,RI Michael_McKeown@Brown.edu 401-863-9807 --- .