RNA Analysis
A 4400 Nucleotide Message is not Expressed in the Mutant. Genomic
DNA adjacent to the site of insertion was used to probe an RNA blot of total
RNA isolated from mt+ and mt- gametes and vegetative cells, mutant gametes
and vegetative cells, and from wild-type zygotes. A 4400 nt message was
expressed at relatively high levels in the wild-type vegetative cells and
zygotes, but expression was greatly reduced in wild-type gametes. The message
was completely absent from the mutant cells indicating that the integration
event generated a null mutation.