Novel Bombyx mori cell lines cultivable at 37°C

Abstract

Four continuous cell lines were established from cultures of embryonic tissue of the silkworm, Bombyx mori, and designated NISES-BoMo-MK, NISES-BoMo-KG, NISES-BoMo-DZ, and NISES-BoMo-OH. The cells were mostly spherical in shape, and could be cultured at 25°C to 37°C. The population doubling time of each cell line was not affected by the temperatures employed, being about one day at both 25°C and 37°C. The karyotype of the cells was typical of lepidopteran cell lines. The number of chromosomes was higher at 37°C than at 25°C. The activity of the enzymes, phosphoglucose isomerase, phosphoglucomutase, isocitrate dehydrogenase, and glucose-6-phosphate dehydrogenase extracted from the cells was higher at 37°C than at 25°C. None of these novel cell lines formed any polyhedra, even with high titer inoculation of Bombyx mori nuclear polyhedrosis virus.