The large structure in this video is the cell nucleus. Yellow dots signify mRNA molecules, each containing a red and a green fluorescent protein, which results in the color yellow. In the course of the five-second video, increasing numbers of red dots can be seen outside the nucleus, in the cell's cytoplasm. The red color indicates that the mRNAs are being translated into proteins. The large blue blobs are granules that sequester mRNAs when cells are stressed. (Credit: Science/AAAS)
