twin of eyeless, a second Pax-6 gene of Drosophila, acts upstream of eyeless in the control of eye development.
The Drosophila Pax-6 gene eyeless (ey) plays a key role in eye development. Here we show tht Drosophila contains a second Pax-6 gene, twin of eyeless (toy), due to a duplication during insect evolution. Toy is more similar to vertebrate Pax-6 proteins than Ey with regard to overall sequence conservation, DNA-binding function, and early expression in the embryo, toy and ey share a similar expression pattern in the developing visual system, and targeted expression of Toy, like Ey, induces the formation of ectopic eyes. Genetic and biochemical evidence indicates, however, that Toy functions upstream of ey by directly regulating the eye-specific enhancer of ey. Toy is therefore required for initiation of ey expression in the embryo and acts through Ey to activate the eye developmental program.
Czerny
T
T
Research Institute of Molecular Pathology, Vienna, Austria.
Halder
G
G
Kloter
U
U
Souabni
A
A
Gehring
W J
WJ
Busslinger
M
M
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D002490:Central Nervous System / Q000196:embryology / Q000378:metabolism; D018983:DNA Footprinting; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000196:embryology / Q000235:genetics* / Q000378:metabolism; D004742:Enhancer Elements, Genetic / Q000235:genetics; D004843:Epistasis, Genetic; D019143:Evolution, Molecular; D005123:Eye / Q000196:embryology / Q000378:metabolism; D005136:Eye Proteins; D005246:Feedback; D018507:Gene Expression Regulation, Developmental; D020131:Genes, Duplicate / Q000235:genetics; D017344:Genes, Insect / Q000235:genetics; D018398:Homeodomain Proteins; D019476:Insect Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation; D009928:Organ Specificity; D000071841:PAX6 Transcription Factor; D051761:Paired Box Transcription Factors; D012097:Repressor Proteins; D015534:Trans-Activators / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism
D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D005136:Eye Proteins; D018398:Homeodomain Proteins; D019476:Insect Proteins; D000071841:PAX6 Transcription Factor; D051761:Paired Box Transcription Factors; D012097:Repressor Proteins; D015534:Trans-Activators; C113278:ey protein, Drosophila; C118464:toy protein, Drosophila