It’s not often that the introductory part of a research talk is beautiful as well as informative, but Hans Clevers achieves both by using this video about the intestinal crypt in his presentations. (Click either screenshot to see the video)
The video shows how stem cells at the base of the intestinal crypt produce the epithelial cells of the intestines, and how the cells are pushed up toward the tip of the villi. Once at the top, the cells die, but are immediately replaced by the next cells. It’s a “clonal conveyor belt”, constantly moving new cells up.
When Clevers’ lab identified crypt base columnar cells as the stem cells responsible for the generation of the rapidly renewing intestinal epithelium, they simultaneously identified the gene Lgr5 as marker for intestinal stem cells. Until their discovery, other groups had used the method of detection the retention of labeled DNA, which suggested other crypt cells as stem cells.
The last part of the video shows how they used the unique expression pattern of LGR5 to create a knock-in mutant in which the tumour suppressor APC is no longer expressed in stem cells, and show that this is sufficient to trigger adenoma formation.
Clevers had the animation made through a company called Digizyme, which specializes in multimedia approaches to present scientific information. It’s a very welcome addition to the home-made powerpoint slides that you usually see in talks, and I appreciate the effort made to pack this information on intestinal stem cells in an, if you’ll pardon the pun, easy to digest format.
Barker, N., van Es, J., Kuipers, J., Kujala, P., van den Born, M., Cozijnsen, M., Haegebarth, A., Korving, J., Begthel, H., Peters, P., & Clevers, H. (2007). Identification of stem cells in small intestine and colon by marker gene Lgr5 Nature, 449 (7165), 1003-1007 DOI: 10.1038/nature06196
Barker, N., Ridgway, R., van Es, J., van de Wetering, M., Begthel, H., van den Born, M., Danenberg, E., Clarke, A., Sansom, O., & Clevers, H. (2008). Crypt stem cells as the cells-of-origin of intestinal cancer Nature, 457 (7229), 608-611 DOI: 10.1038/nature07602