The mouse Hox-1.3 gene is functionally equivalent to the Drosophila Sex combs reduced gene.
To test whether the mouse Hox-1.3 gene is a cognate of the Drosophila Sex combs reduced (Scr) gene, we inserted a hsp 70-Hox-1.3 fusion gene into the Drosophila genome. Transgenic flies displayed Scr-like homeotic transformations after ectopic expression of Hox-1.3 induced by heat shock. In larvae, the thoracic segments T2 and T3 are transformed toward T1. In adults, head structures are dramatically disrupted, including transformation of antenna towards leg. Transformations are not the result of ectopic activation of the endogenous Scr gene. Rather, Hox-1.3 appears to directly regulate Scr target genes, as demonstrated by the ectopic activation of fork head by Hox-1.3. The results suggest that mouse Hox-1.3 cannot only substitute functionally for Drosophila Scr in the determination of external structures but also can participate in the regulatory hierarchy of insect organogenesis.
Zhao
J J
JJ
Brookdale Center for Molecular Biology, Mount Sinai School of Medicine, New York, New York 10029-6574.
Lazzarini
R A
RA
Pick
L
L
D000595:Amino Acid Sequence; D000818:Animals; D030801:Animals, Genetically Modified; D001483:Base Sequence; D004330:Drosophila / Q000235:genetics* / Q000254:growth & development; D004625:Embryo, Nonmammalian / Q000502:physiology; D015870:Gene Expression; D005786:Gene Expression Regulation; D005801:Genes, Homeobox; D006360:Heat-Shock Proteins / Q000235:genetics*; D006358:Hot Temperature; D007814:Larva; D051379:Mice; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides; D016366:Open Reading Frames; D010641:Phenotype; D011993:Recombinant Fusion Proteins; D015183:Restriction Mapping; D017386:Sequence Homology, Amino Acid; D014170:Transformation, Genetic
D006360:Heat-Shock Proteins; D009838:Oligodeoxyribonucleotides; D011993:Recombinant Fusion Proteins