The growth and branching of the epithelial ureteric tree is critical for development of the permanent kidney (metanephros). Current methods of analysis of ureteric branching are mostly qualitative. We have developed a method for measuring the length of individual branches, and thereby the total length of the ureteric tree in 3 dimensions (3D). The method involves confocal microscopy of whole-mount immunostained metanephroi and computer-based image segmentation, skeletonisation and measurement. The algorithm performs semi-automatic segmentation of a set of confocal images and skeletonisation of the resulting binary object. Length measurements and number of branch points are automatically obtained. The final representation can be reconstructed providing a fully rotating 3D perspective of the skeletonised tree. After 36 h culture of E12 mouse metanephroi, the total length of the ureteric tree was 6103 ± 291 μm (mean±SD), a four-fold increase compared with metanephroi cultured for just 6 h (1522 ± 149 μm). Ureteric duct length increased at a rate of 153 μm/h over the first 30 h period and was maximal between 18 and 24 h at 325 μm/h. The distribution of branch lengths at the six time points studied was similar, suggesting tight control of ureteric lengthening and branching. This method will be of use in analysing ureteric growth in kidneys cultured in the presence of specific molecules suspected of regulating ureteric growth. The method can also be used to analyse in vivo kidneys and to quantify branching morphogenesis in other developing organs.
|Number of pages||7|
|Journal||International Journal of Developmental Biology|
|Publication status||Published - 1 Dec 2002|
- Image analysis
- Kidney development