FIG. 2.

Transcript analysis of the brnQ gene. (A) Northern blot analysis of ORF442. Ten micrograms of an RNA sample was separated electrophoretically and transferred by Northern blotting onto a membrane. The blot was probed with a radiolabeled 2.5-kb DNA fragment encompassing brnQ. The sizes of the ribosomal RNAs are marked with arrowheads, and the BrnQ product is indicated by an arrow. (B) Mapping of the 5′ end of the brnQ transcript by primer extension analysis. Total RNA from the parent strain was hybridized with an oligonucleotide complementary to the mRNA of the brnQ locus and extended by avian myeloblastosis virus reverse transcriptase (lane P). Lanes T, G, C, and A correspond to a dideoxy sequencing reaction performed with the same primer. The sequence encompassing the initiation start site (marked by an arrowhead) is enlarged.