Wimmer E A, Simpson-Brose M, Cohen S M, Desplan C, Jäckle H
Abteilung Molekulare Entwicklungsbiologie, Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany.
Mech Dev. 1995 Oct;53(2):235-45. doi: 10.1016/0925-4773(95)00439-8.
The Drosophila gene buttonhead (btd) encodes a zinc-finger protein related to the human transcription factor Sp1. btd is expressed in the syncytial blastoderm embryo in a stripe covering the anlagen of the antennal, intercalary and mandibular head segments. btd has been characterized as a head gap gene, since these segments are deleted in btd mutant embryos. We report here that the cis-acting elements required for btd head stripe expression are contained in a 1 kb DNA fragment, located about 3 kb upstream of the promoter. The four maternal coordinate systems are necessary for correct btd head stripe expression, likely by acting through the 1 kb cis-acting control region. Expression of the btd head stripe depends on the anterior morphogen encoded by the gene bicoid (bcd). bcd-dependent activation also involves the activity of the morphogens of the posterior and dorsoventral systems, hunchback and dorsal, respectively, which act together to control the spatial limits of the expression domain. Finally, the terminal system takes part in the regulation of btd head stripe expression by enhancing activation at low levels of activity and repression at high levels of activity.
果蝇基因钮头（btd）编码一种与人类转录因子Sp1相关的锌指蛋白。btd在合胞体胚盘胚胎中表达，形成一条覆盖触角、间插和下颌头部体节原基的条带。btd被鉴定为一个头部间隙基因，因为在btd突变胚胎中这些体节缺失。我们在此报告，btd头部条带表达所需的顺式作用元件包含在一个1 kb的DNA片段中，该片段位于启动子上游约3 kb处。四个母体坐标系统对于btd头部条带的正确表达是必需的，可能是通过作用于1 kb的顺式作用控制区域。btd头部条带的表达依赖于由双胸（bcd）基因编码的前部形态发生素。bcd依赖性激活还分别涉及后部和背腹系统的形态发生素驼背和背侧的活性，它们共同作用以控制表达域的空间界限。最后，末端系统通过在低活性水平增强激活和在高活性水平抑制来参与btd头部条带表达的调控。
