Intracytoplasmic type A particles in viper spleen cells

Structures resembling typical type A particles were observed in paranuclear inclusions in cultured C-type particle-producing viper cells (VSW cell line). The incidence of type A particle inclusions was low (approximately 0.5% of cell profiles examined) in untreated cells, but both the incidence and size of the inclusions were slightly increased in cells treated with ethidium bromide. This is apparently the first observation of type A particles in cells of a poikilothermic vertebrate.