Imaging Embryonic Morphogenesis in C. elegans - Caenorhabditis Elegans: Molecular Genetics and Development - page 378

ii. The bead mixture should then be resuspended with a pipette tip prior to use
and added to the coverslip as above. Embryos can then be pipetted into the
drop of bead slurry.
iii. No grease feet are needed using this method. Instead, seal the edges as
described above for the standard agar mount, using Valap.
B. 4D Nomarski Imaging of Morphogenesis
1. Introduction
By its very nature, developmental biology requires thinking in four dimensions.
Not only do embryos change dramatically over time, as the seemingly featureless
single-celled zygote is transformed into an embryo with recognizable body axes and
organ systems, but this remarkable transformation occurs in three spatial dimen-
sions. The coordinated changes that occur within the developing embryo include
carefully orchestrated signaling events, changes in gene expression, and morphoge-
netic movements, that is, regulated cell divisions and cell movements that sculpt the
basic body plan as a recognizable organism emerges.
Fig. 2 4D acquisition script running within MicroManager. A screen shot of the Micro-Manager Beanshell
script for 4D acquisition running under Mac OS X 10.5. The script is available at http://worms.zoology.wisc.
edu/4d/4d.html . (For color version of this figure, the reader is referred to the web version of this topic.)