Ten out of 29 temperature-sensitive () mutants of poliovirus lost infectivity at 45° more rapidly than did , and therefore had structural protein defects. This division into structural protein and non-structural protein defectives accorded very closely with their position in the genetic map and with previous tests for maturation defects, enabling the region of the genetic map specifying virus structural protein to be defined. Not all mutants mapping in this region were thermolabile, however. Three out of five revertants from the thermolabile mutants were thermostable and so their thermolability and characters almost certainly resulted from mutations in the same gene, i.e. the defects of these thermolabile mutants were confirmed as residing in structural protein. Four of the thermolabile mutants were sufficiently unstable at the restrictive temperature of explain their character. Three mutants mapping in the structural protein region produced only small amounts of RNA-containing particles and so their defect may act before maturation. Of five structural protein mutants examined, none showed any antigenic difference from . Marked covariation was found between cystine requirement for growth and structural protein defects suggesting that cystine requirement is a property of the structural protein of the virus.


Article metrics loading...

Loading full text...

Full text loading...


Most cited this month Most Cited RSS feed

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error