FACTORS AFFECTING DROSOPHILA NEURON AND MYOCYTE DIFFERENTIATION IN VITRO

Whole Drosophila gastrulae were disaggregated and the cells cultured in vitro under conditions that permitted neurons and myocytes to differentiate. Neuron differentiation was measured by counting the number of axons produced, and myocyte differentiation was measured by counting the number of pulsatile myocytes produced. Modifications of the culture medium enabled at least 300 axons and 40 pulsating myocytes to be produced from the cells of each embryo in 24 h, about a 4-fold greater yield than was previously attainable. Axon production was best at pH 6.8 and 26 degrees C, and pulsations were most numerous at pH 6.9 and 26 degrees C. Cells competent to differentiate in vitro could be obtained from embryos only after the initiation of gastrulation. After gastrulation initiation, the number of such competent cells increased progressively in vivo, reaching a near maximum in embryos 30-min older.