Resistance of Dictyostelium discoideum membranes to saponin permeabilization

Self-induced nystatin resistance in Dictyostelium discoideum.

The cellular slime mold Dictyostelium discoideum is normally susceptible to the action of the polyene antibiotic nystatin. We describe conditions under which transient nystatin resistance can be induced in the absence of detectable changes in sterol composition. These results suggest that nystatin plays a positive role in promoting resistance to itself.

Dictyostelium discoideum

Dictyostelium discoideum is a cellular slime mold [4] that serves as an important model organism [5] in a variety of fields. Cellular slime molds have an unusual life cycle. They exist as separate amoebae, but after consuming all the bacteria in their area they proceed to stream together to form a multicellular organism. These features make them a valuable tool for studying developmental proces...

Differential permeabilization of membranes by saponin treatment of isolated rat hepatocytes. Release of secretory proteins.

Monolayer cultures of rat hepatocytes were treated with increasing concentrations of saponin (prepared from Gypsophila plants) for 30 min at 6 degrees C. Differential permeabilization of the intracellular membranes could be demonstrated: at 0.040 mg of saponin/ml the plasma membrane was permeabilized, as assessed by the release of 50% of the total cellular amount of lactate dehydrogenase, and a...

influx in Dictyostelium discoideum

Translocations in Dictyostelium discoideum.

Fourteen translocations of independent origin were identified in Dictyostelium discoideum on the basis of segregation anomalies of diploids heterozygous for these chromosome rearrangements, all of which led to the cosegregation of unlinked markers. Many of these translocations were discovered in strains mutagenized with MNNG or in strains carrying mutations affecting DNA repair; however, sponta...