Abel T, Michelson A M, Maniatis T
Department of Biochemistry and Molecular Biology, Harvard University, Cambridge, Massachusetts 02138.
Development. 1993 Nov;119(3):623-33. doi: 10.1242/dev.119.3.623.
We have identified a Drosophila transcription factor that binds a sequence element found in the larval promoters of all known alcohol dehydrogenase (Adh) genes. DNA sequence analysis of cDNA clones encoding this protein, box A-binding factor (ABF), reveals that it is a member of the GATA family of transcriptional regulatory factors. ABF-binding sites within the D. mulleri and D. melanogaster larval Adh promoters function as positive regulatory elements and in cotransfection experiments, ABF functions as a transcriptional activator. In further support of a role for ABF in the regulation of Adh expression, ABF mRNA is expressed in the embryonic fat body, a tissue that contains high levels of Adh mRNA. Our studies demonstrate that the fat body develops from segmentally repeated clusters of mesodermal cells, which later expand and coalesce to form the mature fat body. These observations establish ABF as the earliest known fat body precursor marker in the Drosophila embryo. Together with the established role of GATA factors during mammalian development, these results suggest that ABF may play a key role in the organogenesis of the fat body.
我们已经鉴定出一种果蝇转录因子，它能结合在所有已知乙醇脱氢酶（Adh）基因的幼虫启动子中发现的序列元件。对编码该蛋白的cDNA克隆（盒A结合因子，ABF）进行DNA序列分析，结果显示它是转录调节因子GATA家族的一员。在穆勒果蝇和黑腹果蝇幼虫Adh启动子内的ABF结合位点作为正调控元件发挥作用，并且在共转染实验中，ABF作为转录激活因子发挥作用。为进一步支持ABF在Adh表达调控中的作用，ABF mRNA在胚胎脂肪体中表达，脂肪体是一种含有高水平Adh mRNA的组织。我们的研究表明，脂肪体由中胚层细胞的节段性重复簇发育而来，这些细胞随后扩展并合并形成成熟的脂肪体。这些观察结果确立了ABF作为果蝇胚胎中已知最早的脂肪体前体标志物。结合GATA因子在哺乳动物发育过程中已确定的作用，这些结果表明ABF可能在脂肪体的器官发生中起关键作用。
