Complex Interactions Between D/V and A/P Patterning Systems Before Gastrulation Revealed by a 3-D Atlas of Gene Expression Patterns.
1) Computer Science Division, University of California, Berkeley, CA.
2) Life Sciences and Genomics Division, Lawrence Berkeley National Laboratory, Berkeley, CA.
3) Institute for Data Analysis and Visualization, University of California, Davis, CA.
4) Computer Science Department, University of Kaiserslautern, Germany.
Spatial patterns of gene expression in multicellular organisms are typically analyzed by visual inspection of images of in situ hybridizations. This approach is limited to providing only rough qualitative information about gene expression levels and captures relatively little 3-D structure. The Berkeley Drosophila Transcription Network Project (BDTNP) is developing a suite of methods to automatically convert images generated by laser scanning confocal microscopy into comprehensive 3-D maps of gene expression at cellular resolution. The resulting maps provide a quantitative description of embryo morphology and gene expression levels which is amenable to automated statistical analysis. We report on the results of registering 3-D expression data from different Drosophila embryos stained for overlapping subsets of target genes in order to build a composite atlas containing co-expression data for more than 20 early regulatory genes in stage 5 blastoderm. In analyzing this detailed 3-D data, we have made several interesting observations: (1) a complex pattern of variation in nuclear packing density which changes over the course of stage 5 (see also poster by Keränen et al., (2) d/v variation in gap gene expression which is not reflected in pair-rule genes (as in a standard model of pair-rule regulation) and (3) differences between d/v expression patterns and the location of the ventral midline predicted by blastula morphology. These findings suggest that the interaction between the d/v and a/p patterning systems and blastula morphology is more complex than suggested by simple 1-D models of pattern formation.
Last modified March 9, 2006.