Dorsoventral patterning of the Drosophila hindgut is determined by interaction of genes under the control of two independent gene regulatory systems, the dorsal and terminal systems.
Dorsoventral (DV) patterning in the trunk region of Drosophila embryo is established through intricate molecular interactions that regulate Dpp/Scw signaling during the early blastoderm stages. The hindgut of Drosophila, which derives from posterior region of the cellular blastoderm, also shows dorsoventral patterning, being subdivided into distinct dorsal and ventral domains. engrailed (en) is expressed in the dorsal domain, which determines dorsal fate of the hindgut. Here we show that a repressor Brk restricts en expression to the dorsal domain of the hindgut. Expression domain of brk during early blastdermal stages is defined through antagonistic interaction with dpp, and expression domains of dpp and brk in the early blastoderm include prospective hindgut domain. After stage 9, dpp expression in the dorsal domain of the hindgut primordium disappears, but, the brk expression in the ventral domain continues. It was found that Dorsocross (Doc), which is a targe gene of Dpp, is responsible for restricting brk expression to the ventral domain of the hindgut. On the other hand, activation of en is under the control of brachyenteron (byn) that is regulated independently of dpp, brk, and Doc. The cooperative interaction of common DV positional cues with byn during hindgut development represents another aspect of mechanisms of DV patterning in the Drosophila embryo.
Department of Biology and Chemistry, Yamaguchi University, Yamaguchi 753-8512, Japan.
Takashi
T
Hamaguchi
Shigeo
S
Takashima
Aiko
A
Okamoto
Misa
M
Imaoka
Takashi
T
Okumura
Ryutaro
R
Murakami
D000818:Animals; D001756:Blastoderm / Q000254:growth & development; D019521:Body Patterning / Q000235:genetics*; D004330:Drosophila / Q000033:anatomy & histology / Q000235:genetics* / Q000254:growth & development; D029721:Drosophila Proteins / Q000235:genetics*; D018507:Gene Expression Regulation, Developmental; D018398:Homeodomain Proteins / Q000235:genetics; D012097:Repressor Proteins / Q000235:genetics; D015534:Trans-Activators / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics
D029721:Drosophila Proteins; C063459:En protein, Drosophila; D018398:Homeodomain Proteins; D012097:Repressor Proteins; D015534:Trans-Activators; D014157:Transcription Factors; C118082:brk protein, Drosophila; C451031:byn protein, Drosophila; C064196:dpp protein, Drosophila