An electron microscope study of infection by the blue-green algal virus SM-1

Abstract

The morphology of unicellular blue-green algae ( Synechococcus) infected with virus SM-1 has been studied in thin sections prepared at various times during the 48 hr required for one cycle of virus growth. No changes in the photosynthetic lamellae are seen prior to lysis, in contrast to the extensive invagination observed in other blue-green algal virus systems. SM-1 virions accumulate in the nucleoplasm; at last times the entire space interior to the photosynthetic lamellae is packed with virus particles. Forms that could be precursors of complete particles have been identified; these include apparently empty heads and condensed “cores.” One or both of these forms could be artifacts of preparation.