Fluorescent fusion proteins encoded by mRNAs, transcribed in vitro, are used to label appropriate portions of cells (i.e., chromosomes via H2B-GFP or membranes). Mixes of mRNA are microinjected with glass needles directly into the embryo at the four-cell stage by use of a picospritzer (see 1 in the figure). For analysis of the early neural plate, the two dorsal cells are injected. Embryos are then grown to stage 13 for early neural plate development. Embryos were imaged on a Zeiss LSM 510 using a 40X objective.