These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.
Pubmed for Handhelds
PUBMED FOR HANDHELDS
Search MEDLINE/PubMed
Title: A Ca(2+)-dependent early functional heterogeneity in amoebae of Dictyostelium discoideum, revealed by flow cytometry. Author: Azhar M, Manogaran PS, Kennady PK, Pande G, Nanjundiah V. Journal: Exp Cell Res; 1996 Sep 15; 227(2):344-51. PubMed ID: 8831572. Abstract: When freshly starved amoebae of Dictyostelium discoideum are loaded with the Ca(2+)-specific dye indo-1/ AM and analyzed in a fluorescence-activated cell sorter, they exhibit a quasi-bimodal distribution of fluorescence. This permits a separation of the population into two classes: H, or "high Ca(2+)-indo-1 fluorescence," and L, or "low Ca(2+)-indo-1 fluorescence." Simultaneous monitoring of Ca(2+)-indo-1 and Ca(2+)-chlortetracycline fluorescence shows that by and large the same cells tend to have high (or low) levels of both cytoplasmic and sequestered Ca2+. Next we label H cells with tetramethylrhodamine isothiocyanate (TRITC) and mix them in a 1:4 ratio with L cells. In the slugs that result, TRITC fluorescence is confined mainly to the anterior prestalk region. This implies that amoebae with relatively high Ca2+ at the vegetative stage tend to develop into prestalk cells and those with low Ca2+ into prespores. Polysphondylium violaceum, a cellular slime mold that does not possess prestalk and prespore cells, also does not display a Ca(2+)-dependent heterogeneity at the vegetative stage or in slugs. Finally, confirming earlier findings with the fluorophore fura-2 (Azhar et al., Curr. Sci. 68, 337-342 (1995)), a prestalk-prespore difference in cellular Ca2+ is present in the cells of the slug in vivo. These findings are discussed in light of the possible roles of Ca2+ for cell differentiation in D. discoideum.[Abstract] [Full Text] [Related] [New Search]