Characterization of the intergenic RNA profile at abdominal-A and Abdominal-B in the Drosophila bithorax complex. Author Esther Bae, Vincent Calhoun, Michael Levine, Edward Lewis, Robert Drewell Publication Year 2002 Type Journal Article Abstract The correct spatial expression of two Drosophila bithorax complex (BX-C) genes, abdominal-A (abdA) and Abdominal-B (AbdB), is dependent on the 100-kb intergenic infraabdominal (iab) region. The iab region is known to contain a number of different domains (iab2 through iab8) that harbor cis-regulatory elements responsible for directing expression of abdA and AbdB in the second through eighth abdominal segments. Here, we use in situ hybridization to perform high-resolution mapping of the transcriptional activity in the iab control regions. We show that transcription of the control regions themselves is abundant and precedes activation of the abdA and AbdB genes. As with the homeotic genes of the BX-C, the transcription patterns of the RNAs from the iab control regions demonstrate colinearity with the sequence of the iab regions along the chromosome and the domains in the embryo under the control of the specific iab regions. These observations suggest that the intergenic RNAs may play a role in initiating cis regulation at the BX-C early in development. Keywords Animals, Drosophila, Drosophila Proteins, Genes, Regulator, In Situ Hybridization, Transcription, Genetic, Genes, Insect, Transcription Factors, RNA, Messenger, Homeodomain Proteins, Nuclear Proteins Journal Proc Natl Acad Sci U S A Volume 99 Issue 26 Pages 16847-52 Date Published 12/2002 Alternate Journal Proc. Natl. Acad. Sci. U.S.A. Google ScholarBibTeXEndNote X3 XML