When they make milk they have signals for turning on the betagalactoglobulin promoter and expressing the gene of interest.

泌乳的时候,β-乳球蛋白启动子受信号调控而开启,目的基因得以表达

耶鲁公开课 - 生物医学工程探索课程节选

There are molecules in cells that give the DNA the signal that it's time to transcribe and express a gene, those are called transcription factors, we'll talk about them a bit later.

在细胞中有些分子能够,给DNA发出信号告诉它,是时候转录和表达某基因了,这些分子叫做转录因子,晚些时候我们会讲它们

耶鲁公开课 - 生物医学工程探索课程节选