Expression of IC140 transcripts in wild-type,
ida7, and rescued strains. Shown here are Northern blots
of total RNA isolated before (0) or after (45) deflagellation. RNA (20
μg per lane) was separated on a 1% formaldehyde agarose gel,
transferred to a Magnagraph membrane, and hybridized to a 1.6-kb cDNA
fragment of the IC140 gene. A single 3.7-kb transcript is present in
both the wild-type and AH1, and the expression of this transcript is
up-regulated by deflagellation. The 3.7-kb transcript is completely
missing in ida7. A smaller transcript is expressed at
high levels both before and after deflagellation in the 5A strain.
Hybridizing the blot with a control probe for the CRY1 gene,
which encodes the S14 ribosomal protein subunit, confirmed that equal
amounts of RNA were loaded in each lane (Perrone and Porter,
unpublished results).