Physicochemical and Morphological Relationships of some Arthropod-borne Viruses to Bluetongue Virus—A New Taxonomic Group. Electron Microscopic Studies Murphy, F. A. and Borden, E. C. and Shope, R. E. and Harrison, Alyne,, 13, 273-288 (1971), doi = https://doi.org/10.1099/0022-1317-13-2-273, publicationName = Microbiology Society, issn = 0022-1317, abstract= SUMMARY The morphology and mode of maturation of a number of relatively solvent resistant arboviruses were examined by thin-section and negative-stain electron microscopy of infected mouse brain and cell culture specimens. These viruses, which have physicochemical properties distinct from other arboviruses, included Colorado tick fever, Tribec, Wad Medani, Chenuda, Irituia, Palyam, Lebombo, epizootic haemorrhagic disease of deer and bluetongue. They were 65 to 80 nm. in diameter and matured in the cytoplasm as unenveloped particles with an electron-dense core. Virus development occurred in association with a cytoplasmic granular matrix and was accompanied by formation of regularly substructured filaments and tubules. Surface architecture was compatible with icosahedral symmetry with T = 3 (32 capsomeres). The combination of taxonomic parameters, morphologic and morphogenetic as well as physicochemical, was distinct from that of any presently recognized virus group. The independent classification of these viruses with bluetongue as the type virus is thus proposed., language=, type=