International Mammalian Genome Society

logo18th International Mouse Genome Conference

17-22 October 2004, Seattle, USA


Walls JR 1, Sled JG 1, Bruneau BG 2, Sharpe J 3, Henkelman RM 1

1 Mouse Imaging Centre, Hospital for Sick Children, Toronto, Canada, 2 Hospital for Sick Children, Toronto, Canada, 3 Human Genetics Unit, Medical Research Council, Edinburgh, United Kingdom

The ability to visualize the 3D organization of biological tissue is essential to unravelling its complexities.  A new imaging technique called Optical Projection Tomography (OPT), essentially an optical version of X-Ray computed tomography (CT), fills a gap among current imaging modalities by creating molecularly specific, cellular resolution images of specimens up to 1 cc in size.

The visualization of a specific gene’s pattern of expression is essential to gain an understanding of its role.  Mutant comparisons performed with OPT are more sensitive to spatial complexity than comparisons performed with serial sectioning techniques that might alter subtle morphology.  Common optical markers can be used to highlight a region of interest or a particular genetic expression for enhanced visualization.  We have acquired cellular resolution OPT data sets of whole E9.5 to E12.5 mouse embryos with a fluorescently labelled cardiac specific pattern of gene expression to examine the full extent of 3D morphological differences between control and mutant specimens.

Vascular development is difficult to study without 3D visualization.  Resolution of vessels less than 10 microns in size is needed to obtain a complete 3D map of the vasculature.  Vessel imaging is a promising application of OPT as it meets the resolution criteria for smaller vessels while retaining information from the entire specimen.  We have acquired a complete map of the vasculature of an E16.5 mouse head with vessel resolution of 15 microns.  It is expected that the development we are undertaking will allow the modality to resolve the capillary vessels.

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