Abstract
Previously we showed that the rising cell masses of cellular slime molds orient away from high concentrations of ammonia gas, presumably by speeding up the cells on one side. Here we show that in the same way NH3 could also be involved in the highly sensitive phototaxis found in the migrating slugs of Dictyostelium discoideum. We have evidence that light increases their speed of migration and their production of NH3. Since unilateral light is concentrated on the distal side of a cell mass by the “lens effect,” this leads to the obvious hypothesis that the light stimulates the local production of NH3, which, in turn, stimulates the cells in the illuminated region to move faster.
Keywords: slime molds, gas orientation, chemotaxis
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- BONNER J. T., CLARKE W. W., Jr, NEELY C. L., Jr, SLIFKIN M. K. The orientation to light and the extremely sensitive orientation to temperature gradients in the slime mold Dictyostelium discoideum. J Cell Physiol. 1950 Oct;36(2):149–158. doi: 10.1002/jcp.1030360203. [DOI] [PubMed] [Google Scholar]
- BONNER J. T., DODD M. R. Evidence for gas-induced orientation in the cellular slime molds. Dev Biol. 1962 Oct;5:344–361. doi: 10.1016/0012-1606(62)90018-0. [DOI] [PubMed] [Google Scholar]
- FRANCIS D. W. SOME STUDIES ON PHOTOTAXIS OF DICTYOSTELIUM. J Cell Physiol. 1964 Aug;64:131–138. doi: 10.1002/jcp.1030640113. [DOI] [PubMed] [Google Scholar]
- Kitami M. The motive force of the migrating pseudoplasmodium of Dictyostelium discoideum under dark and light conditions. J Cell Sci. 1982 Aug;56:131–140. doi: 10.1242/jcs.56.1.131. [DOI] [PubMed] [Google Scholar]
- Poff K. L., Loomis W. F., Jr Control of phototactic migration in Dictyostelium discoideum. Exp Cell Res. 1973 Nov;82(1):236–240. doi: 10.1016/0014-4827(73)90266-8. [DOI] [PubMed] [Google Scholar]
- Schindler J., Sussman M. Ammonia determines the choice of morphogenetic pathways in Dictyostelium discoideum. J Mol Biol. 1977 Oct 15;116(1):161–169. doi: 10.1016/0022-2836(77)90124-3. [DOI] [PubMed] [Google Scholar]