trithorax regulates multiple homeotic genes in the bithorax and Antennapedia complexes and exerts different tissue-specific, parasegment-specific and promoter-specific effects on each

Citations Over TimeTop 10% of 1993 papers

Abstract

The trithorax (trx) gene is required for normal development of the body plan in Drosophila embryos and adults. Mutations in trx cause homeotic transformations throughout the body. Genetic studies suggest that trx encodes a positive regulatory factor required throughout development for normal expression of multiple homeotic genes of the bithorax and Antennapedia complexes (BX-C and ANT-C). To determine how trx influences homeotic gene expression, we examined the expression of the BX-C genes Ultrabithorax, abdominal-A, Abdominal-B and the ANT-C genes Antennapedia, Sex combs reduced and Deformed in trx embryos. We show that trx does indeed exert its effects by positively regulating homeotic gene expression and that its effects on expression of individual homeotic genes are complex: each of the BX-C and ANT-C genes examined exhibits different tissue-specific, parasegment-specific and promoter-specific reductions in their expression. This implies that each of these genes have different requirements for trx in different spatial contexts in order to achieve normal expression levels, presumably depending on the promoters involved and the other regulatory factors bound at each of their multiple tissue- and parasegment-specific cis-regulatory sites in different regions of the embryo. These results also imply that those components of homeotic gene expression patterns for which trx is dispensable, require other factors, possibly those encoded by other trithorax-like genes.

Related Papers

• → trithorax regulates multiple homeotic genes in the bithorax and Antennapedia complexes and exerts different tissue-specific, parasegment-specific and promoter-specific effects on each(1993)120 cited
• → Molecular characterization of the trithorax gene, a positive regulator of homeotic gene expression in Drosophila(1991)82 cited
• → Ectopic expression of homeotic genes caused by the elimination of the Polycomb gene in Drosophila imaginal epidermis(1988)96 cited
• → Trans-regulation of thoracic homeotic selector genes of the Antennapedia and bithorax complexes by the trithorax group genes: absent, small, and homeotic discs 1 and 2(1995)65 cited
• → Hox genes: Losses, gains and targets(1992)