Control of the expression of the bithorax complex genes abdominal-A and abdominal-B by cis-regulatory regions in Drosophila embryos.
The abdominal-A (abd-A) and Abdominal-B (Abd-B) genes of the bithorax complex (BX-C) specify the identity of most of the Drosophila abdomen. Six different classes of infraabdominal (iab) mutations within the BX-C transform a subset of the parasegments affected by the lack of these two genes. It is thought that these mutations define parasegmental cis-regulatory regions that control the expression of abd-A and Abd-B. By staining embryos mutant for different iab mutations with anti-abd-A and anti-Abd-B antibodies I show here that the expression of Abd-B (and probably also abd-A) exhibit a parasegmental regulation. I have also studied the significance of the chromosomal order of parasegmental iab regulatory sequences, and the possible presence of chromosomal 'boundaries' between them, by looking at the expression of abd-A and Abd-B in embryos carrying the Uab and Mcp mutations. These data are discussed in the light of models of parasegmental-specific regulatory regions within the BX-C.
Centro de Biología Molecular, Facultad de Ciencias, Universidad Autónoma de Madrid, Spain.
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Sánchez-Herrero
D000818:Animals; D004247:DNA / Q000235:genetics*; D004330:Drosophila; D005786:Gene Expression Regulation / Q000235:genetics*; D005801:Genes, Homeobox / Q000235:genetics*; D016253:Microscopy, Immunoelectron; D009154:Mutation / Q000235:genetics; D012045:Regulatory Sequences, Nucleic Acid / Q000502:physiology*
D004247:DNA