Quantitative Live Imaging Describes Morphogenetic Nuclear Movements Prior to Gastrulation.
1) Life Sciences and Genomics Division, Lawrence Berkeley National Laboratory, Berkeley, CA.
2) Computer Science Division, University of California, Berkeley, CA.
3) Institute for Data Analysis and Visualization, University of California, Davis, CA.
4) Computer Science Department, University of Kaiserslautern, Germany.
As part of the Berkeley Drosophila Transcription Network Project we are creating a three-dimensional atlas of gene expression and embryo morphology at cellular resolution (see Fowlkes et al., Knowles et al., Keränen et al.). One novel observation we have made is that there is a systematic change in nuclear packing densities during stage 5 (interphase cycle 14) when fixed embryos of different ages are compared (see Fowlkes et al.). To further understand this nuclear movement, we have studied this process in live histone2A-GFP embryos. By tracking nuclear positions during the ~50 minutes between the 13th cleavage cycle and gastrulation for multiple embryos in different orientations, we have composed whole-embryo maps of the vector flow-fields, which describe the movement of nuclei, and the nuclear packing densities throughout stage 5 on large parts of the embryo surface. The density maps produce patterns which correlate with the dorsal-ventral orientation of the embryo and the future location of the ventral furrow. There is a good correlation between the density maps derived from fixed embryos and live embryos.
Last modified March 9, 2006.