title: Stimulation by DIF causes an increase of intracellular Ca2+ in Dictyostelium discoideum.
abstract: Using fluorescence-activated cell sorting (FACS), we have studied the effect of the differentiation-inducing factor (DIF) on cellular Ca2+ in Dictyostelium discoideum. We have shown previously that freshly starved or postaggregation amoebae are heterogenous with respect to the amounts of cellular Ca2+ that they contain; the L or "low Ca2+" class exhibits a prespore tendency and the H or "high Ca2+" class exhibits a prestalk tendency. Upon adding DIF, within 2 min there is an approximately twofold increase in the relative fraction of amoebae falling in the H class. A major part of the increase is caused by Ca2+ influx from the extracellular medium. Therefore a rise in the level of cellular Ca2+ is an early step in the signal transduction pathway following stimulation by DIF. Also, in parallel with the cellular heterogeneity in respect of Ca2+ content, there is a heterogeneity in the response to DIF, which appears to be restricted to L cells.
authors.affiliation: Developmental Biology and Genetics Laboratory, Indian Institute of Science, Bangalore, India.
authors.forename: M
authors.initials: M
authors.lastname: Azhar
authors.forename: P K
authors.initials: PK
authors.lastname: Kennady
authors.forename: G
authors.initials: G
authors.lastname: Pande
authors.forename: V
authors.initials: V
authors.lastname: Nanjundiah
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002614:Chelating Agents / Q000494:pharmacology; D004023:Dictyostelium / Q000187:drug effects / Q000378:metabolism; D004533:Egtazic Acid / Q000494:pharmacology; D006588:Hexanones / Q000494:pharmacology*
chemical_list: D002614:Chelating Agents; D006588:Hexanones; C053433:1-((3,5-dichloro)-2,6-dihydroxy-4-methoxyphenyl)-1-hexanone; D004533:Egtazic Acid; D002118:Calcium