Effects of folic acid upon filopodia of Dictyostelium discoideum vegetative amoebae.
Living vegetative D, discoideum amoebae were studied to determine whether their filopodia respond to folic acid, a chemoattractant for these cells. Exponentially growing amoebae (ca. 10 micron diameter) exhibit 5-30 micron long filopodia; at stationary phase, aggregation competent amoebae have numerous multibranched filopodia up to 100 micron long. Folic acid was observed to stimulate production, elongation, and branching of filopodia with its effects progressively changing as the amoebae approach aggregation. Filopodial construction was also found to be dependent upon Mg2+ levels. The significance of these results is discussed with respect to progressive changes within the vegetative phase as well as to the mechanisms of amoeboid movement, pseudopodial activity, and chemotaxis.
D002633:Chemotaxis / Q000187:drug effects*; D004023:Dictyostelium / Q000187:drug effects*; D005492:Folic Acid / Q000494:pharmacology*; D008274:Magnesium / Q000378:metabolism
D005492:Folic Acid; D008274:Magnesium