title: Evidence that the Abdominal-B r element function is conferred by a trans-regulatory homeoprotein.
abstract: The Abdominal-B gene is a homeotic gene located in the distal-most region of the bithorax complex (BX-C). Based on complementation analysis it has been proposed that the gene contains two separable genetic elements, called the m and r elements. The r element has a chiefly regulatory function confined to parasegment 14. In a reverse Northern screen of the distal-most BX-C DNA, we found four distinct areas that are transcribed in the embryo. One of the transcripts spans a large genomic region which, upon disruption by rearrangement breakpoints, causes loss of r element function. This transcript is expressed in the early embryo in a single domain apparently corresponding to parasegment 14. We propose that the small homeoprotein encoded by the transcript acts as a trans-regulator to confer r element function.
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D003001:Cloning, Molecular; D004331:Drosophila melanogaster / Q000196:embryology / Q000235:genetics*; D005801:Genes, Homeobox; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D012333:RNA, Messenger / Q000235:genetics* / Q000378:metabolism; D015183:Restriction Mapping; D012689:Sequence Homology, Nucleic Acid; D014018:Tissue Distribution; D014157:Transcription Factors / Q000235:genetics*
chemical_list: D012333:RNA, Messenger; D014157:Transcription Factors