A morphological comparison of Bittner and influenza viruses

Abstract

By the negative staining technique both Bittner and influenza viruses are pleomorphic and have similar fringed surfaces. The present study revealed that Bittner virus had one characteristic form consisting of a head approximately 1000 Å. in diameter and a tail up to 3000 Å. long. On storage at −20° C. Bittner virus broke down to reveal a round internal component of 750 Å. diameter. Influenza virus did not break down on storage at −20° C. but a small number of spontaneously disrupted particles revealed that the internal component was in the form of a coil. The circular internal component of Bittner virus is presumed to be spherical and corresponds to the previously described type A particles as seen by negative staining. The complete enveloped particle corresponds to the type B particle of thin sectioning. It is suggested that the thinly sectioned mature type B particle may be a degenerate form of the so-called immature type B particle. In addition, it is suggested that certain murine RNA tumour viruses may have a morphology distinctive to them.