Involvement of winged eye encoding a chromatin-associated bromo-adjacent homology domain protein in disc specification.
How organ identity is determined is a fundamental question in developmental biology. In Drosophila, field-specific selector genes, such as eyeless (ey) for eyes and vestigial (vg) for wings, participate in the determination of imaginal disc-specific identity. We performed gain-of-function screening and identified a gene named winged eye (wge), which encodes a bromo-adjacent homology domain protein that localizes at specific sites on chromosomes in a bromo-adjacent homology domain-dependent manner. Overexpression of wge-induced ectopic wings with antero-posterior and dorso-ventral axes in the eye field in a region-specific Hox gene-(Antennapedia) independent manner. Overexpression of wge was sufficient for ectopic expression of vg in eye discs. A context-dependent requirement of wge was demonstrated for vg expression in wing discs and for expression of eyes absent (eya), a control gene for eye development downstream of ey, in eye discs. In contrast to vg, however, overexpression of wge inhibited EY-mediated expression of eya. Consistent with colocalization on polytene chromosomes of WGE and Posterior sex combs (PSC), a Polycomb group gene product, we demonstrated an antagonistic genetic interaction between wge and Psc. These findings suggest that wge functions in the determination of disc-specific identity, downstream of Hox genes.
Katsuyama
Tomonori
T
Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai 980-8578, Japan.
Sugawara
Tomo
T
Tatsumi
Masanobu
M
Oshima
Yoshiteru
Y
Gehring
Walter J
WJ
Aigaki
Toshiro
T
Kurata
Shoichiro
S
D000818:Animals; D001483:Base Sequence; D002843:Chromatin / Q000378:metabolism; D002868:Chromosomal Proteins, Non-Histone / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000235:genetics; D004330:Drosophila / Q000235:genetics* / Q000254:growth & development; D029721:Drosophila Proteins / Q000235:genetics*; D005123:Eye / Q000254:growth & development; D051858:Forkhead Transcription Factors / Q000235:genetics*; D018507:Gene Expression Regulation, Developmental; D008969:Molecular Sequence Data; D009024:Morphogenesis / Q000235:genetics; D009928:Organ Specificity / Q000235:genetics*; D014921:Wings, Animal / Q000254:growth & development
D002843:Chromatin; D002868:Chromosomal Proteins, Non-Histone; D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D051858:Forkhead Transcription Factors; C506268:wge protein, Drosophila