Effects of pH, Ca2+, temperature, and protease pretreatment on interkingdom fusion

Abstract

The incubation of carrot protoplasts and culturedXenopus cells in a protease solution has been shown to enhance their subsequent interkingdom fusion by a high pH/high Ca²⁺ method. The effects of Ca²⁺ concentration, pH, and temperature on the frequency of heterokaryon formation have also been studied. Potentially viable heterokaryons have been repeatedly produced at high frequencies (consistently >10%), far exceeding those so far achieved in PEG-mediated fusion. Cell aggregates are readily dispersed after this method of fusion, permitting the accurate estimation of fusion frequencies.