Chromosomal binding sites of Ultrabithorax homeotic proteins.
Drosophila homeotic genes and their vertebrate cognates, the Hox genes, encode homeodomain proteins that are thought to control segment-specific morphogenesis by regulating subordinate target genes. Although expression of many genes is thought to be influenced by homeotic/Hox function, little is known about the genes they directly regulate in the developing embryo. One of the Drosophila homeotic genes is Ultrabithorax (Ubx) that specifies the identity of specific thoracic and abdominal metameres. Towards identifying genes directly regulated by Ubx we have mapped the binding sites of Ubx proteins (UBX) in polytene chromosomes. We found that the UBX isoforms Ia and IVa accumulate in about 100 discrete chromosomal sites. Most, if not all, the sites are the same for the two UBX isoforms. These sites are all euchromatic, include both bands and interbands and are reproducible from chromosome to chromosome. Some of these sites correspond to the locations of known genes that are good candidates, or are known to be, under direct Ubx control.
Botas
J
J
Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA.
Auwers
L
L
D000818:Animals; D030801:Animals, Genetically Modified; D001665:Binding Sites; D002874:Chromosome Mapping; D002875:Chromosomes / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental; D005801:Genes, Homeobox; D017344:Genes, Insect; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism*; D007814:Larva; D009024:Morphogenesis / Q000235:genetics; D011401:Promoter Regions, Genetic; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012469:Salivary Glands / Q000378:metabolism; D014157:Transcription Factors
D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D018840:HSP70 Heat-Shock Proteins; D018398:Homeodomain Proteins; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors; C066177:Ubx protein, Drosophila