Schöck F, Purnell B A, Wimmer E A, Jäckle H
Lehrstuhl für Genetik, Universität Bayreuth, Universitätsstrasse 30, NW1, 95447, Bayreuth, Germany.
Mech Dev. 1999 Dec;89(1-2):125-32. doi: 10.1016/s0925-4773(99)00215-4.
The Drosophila gene buttonhead (btd) is required for the formation of the mandibular, the intercalary and the antennal head segments of the embryo. The btd protein (BTD) is functionally and structurally related to the human C(2)H(2) zinc finger transcription factor Sp1. A second Sp1-like Drosophila gene, termed Drosophila Sp1 (D-Sp1), had been identified on the basis of a partial sequence showing that the gene encodes a characteristic zinc finger domain, composed of three finger motifs similar to both Sp1 and btd. D-Sp1 is located in the same cytological location as btd in chromosome band 9A on the X-chromosome. It had been proposed that D-Sp1 and btd are likely to act as a gene pair and function in a at least partially redundant manner. Here we report the molecular analysis of D-Sp1 and its expression pattern during embryonic and larval development. We show that D-Sp1 acts as a transcriptional regulator. Lack-of-function analysis combined with rescue and gain-of-function studies indicates that btd and D-Sp1 play essential and redundant roles for mechanosensory organ development. However, D-Sp1 lacks the specific features of BTD required for embryonic intercalary and antennal segment formation.
果蝇基因钮头（btd）是胚胎下颌、节间和触角头部节段形成所必需的。btd蛋白（BTD）在功能和结构上与人类C(2)H(2)锌指转录因子Sp1相关。基于一个部分序列已鉴定出第二个类似Sp1的果蝇基因，称为果蝇Sp1（D-Sp1），该序列表明该基因编码一个特征性锌指结构域，由三个与Sp1和btd相似的指基序组成。D-Sp1位于X染色体9A染色体带中与btd相同的细胞学位置。有人提出D-Sp1和btd可能作为一个基因对发挥作用，且至少部分以冗余方式发挥功能。在此我们报告D-Sp1的分子分析及其在胚胎和幼虫发育过程中的表达模式。我们表明D-Sp1作为一种转录调节因子发挥作用。功能缺失分析与拯救和功能获得研究相结合表明，btd和D-Sp1对机械感觉器官发育起着至关重要的冗余作用。然而，D-Sp1缺乏胚胎节间和触角节段形成所需的BTD的特定特征。
