Fuss B, Hoch M
Max-Planck-Institut für biophysikalische Chemie, Abt. Molekulare Entwicklungsbiologie, Göttingen, Germany.
Mech Dev. 1998 Dec;79(1-2):83-97. doi: 10.1016/s0925-4773(98)00172-5.
We have identified and cloned a novel type of homeobox gene that is composed of two homeodomains and is expressed in the Drosophila endoderm. Mutant analysis reveals that its activity is required at the foregut/midgut boundary for the development of the proventriculus. This organ regulates food passage from the foregut into the midgut and forms by the infolding of ectoderm and endoderm-derived tissues. The endodermal outer wall structure of the proventriculus is collapsed in the mutants leading to a failure of the ectodermal part to invaginate and build a functional multilayered organ. Lack-of-function and gain-of-function experiments show that the expression of this homeobox gene in the proventriculus endoderm is induced in response to Wingless activity emanating from the ectoderm/endoderm boundary whereas its expression in the central midgut is controlled by Dpp and Wingless signalling emanating from the overlying visceral mesoderm.
我们已经鉴定并克隆了一种新型的同源异型框基因，该基因由两个同源结构域组成，在果蝇内胚层中表达。突变分析表明，其活性在前肠/中肠边界对于前胃的发育是必需的。这个器官调节食物从前肠进入中肠，并由外胚层和内胚层衍生组织的内陷形成。在前胃突变体中，内胚层外壁结构塌陷，导致外胚层部分无法内陷并构建功能性多层器官。功能缺失和功能获得实验表明，该同源异型框基因在前胃内胚层中的表达是对外胚层/内胚层边界发出的无翅活性的响应而诱导的，而其在中肠中部的表达则受来自上方内脏中胚层发出的Dpp和无翅信号的控制。
