Hülskamp M, Tautz D
Institut für Genetik und Mikrobiologie, Universität München, Germany.
Bioessays. 1991 Jun;13(6):261-8. doi: 10.1002/bies.950130602.
Gap genes stand at the top of the zygotic segmentation hierarchy in Drosophila. Their expression domains are set up by a combination of maternal regulatory signals and interactions among themselves. In addition, these regulatory pathways are partially redundantly specified by the maternal and zygotic genomes, or by multiple zygotic gene products. The gap genes code for transcription factors which exert their function by forming short-range morphogenetic gradients; differential concentrations of these transcription factors can either act as activators or as repressors for the expression domains of neighboring genes. It is possible to view the gap genes as a system of genes that subdivides the embryo by forming an activation-repression cascade proceeding from anterior towards posterior.
间隙基因处于果蝇合子分割层级的顶端。它们的表达域由母体调控信号以及它们之间的相互作用共同建立。此外，这些调控途径部分由母体基因组和合子基因组冗余指定，或者由多个合子基因产物指定。间隙基因编码转录因子，这些转录因子通过形成短程形态发生梯度发挥其功能；这些转录因子的不同浓度既可以作为相邻基因表达域的激活剂，也可以作为抑制剂。可以将间隙基因视为一个基因系统，该系统通过形成从前向后的激活-抑制级联来细分胚胎。
