Planarians Sense Simulated Microgravity and Hypergravity

Figure 2

Results of Experiment . Planarians regenerate in 3 g hypergravity but not in the microgravity simulated by the 60°/s RPM. (a) Schedule of Experiment . (b) Comparison between sample group and control group in the RPM. At day 13 all RPM animals appeared dead, while controls were regenerated and healthy. (c) Comparison between sample group and control group in the LDC. DAPI staining (green) shows that both groups regenerated properly the missing structures. In both groups animals fissioned during the experiment and thus at day 13 animals at different stages of regeneration are found. In the image, a completely regenerated brain in the anterior region is labelled with white arrows and a regenerating one of a planarian fragment is indicated by a yellow arrowhead. The counting of pH3 positive cells in LDC planarians, grouped according to their morphology after their differential fissioning, indicates that under hypergravity conditions there is a slight decrease in the number of proliferative cells, although it is not statistically significant. Graphs error bars represent standard error of the mean. Data were analyzed by Student’s -test. Differences are considered significant at .