Developmental expression of a regulatory gene is programmed at the level of splicing.
We report sequence and transcript structures for a 6191-base chromosomal segment containing the presumptive regulatory gene from Drosophila, suppressor-of-white-apricot [su(wa)]. Our results indicate that su(wa) expression is controlled by regulating occurrence of specific splices. Seven introns are removed from the su(wa) primary transcript during precellular blastoderm development. The sequence of this mature RNA indicates that it is a conventional messenger RNA. In contrast, after cellular blastoderm the first two of these introns cease to be efficiently removed. The mature RNAs resulting from this failure to remove the first two introns have structures quite unexpected of mRNAs. We propose that postcellular blastoderm su(wa) expression is repressed by preventing splices necessary to produce a functional mRNA. Implications and mechanisms are discussed.
Chou
T B
TB
Department of Biochemistry, State University of New York, Stony Brook 11794.
Zachar
Z
Z
Bingham
P M
PM
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D004262:DNA Restriction Enzymes; D004330:Drosophila / Q000235:genetics*; D005809:Genes, Regulator; D008969:Molecular Sequence Data; D014176:Protein Biosynthesis; D012326:RNA Splicing; D012333:RNA, Messenger / Q000235:genetics; D013489:Suppression, Genetic; D014158:Transcription, Genetic
D012333:RNA, Messenger; D004262:DNA Restriction Enzymes