Open AccessTranscription of the intergenic regions of the tubulin gene cluster ofTrypanosoma brucei: evidence for a polyclstronic transcription unit in a eukaryote
Author(s) -
Martin A. Imboden,
Peter W. Laird,
Marianne Affolter,
Thomas Seebeck
Publication year - 1987
Publication title -
nucleic acids research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 9.008
H-Index - 537
eISSN - 1362-4954
pISSN - 0305-1048
DOI - 10.1093/nar/15.18.7357
Subject(s) - biology , transcription (linguistics) , intergenic region , gene , trypanosoma brucei , polyadenylation , genetics , exon , microbiology and biotechnology , primary transcript , gene cluster , rna splicing , messenger rna , alternative splicing , rna , genome , philosophy , linguistics
The tubulin genes of T. brucei are clustered in a tightly packed array of alternating alpha- and beta-genes. The steady state mRNA contains one abundant mRNA species each for alpha- and beta-tubulin, both carrying the identical 35 nt mini-exon sequence at their 5'-ends. We have used in vitro run-on transcription assays to investigate the mechanism of tubulin gene transcription in T. brucei. Our results show that the regions between the individual tubulin genes are transcribed at the same rate as are the genes themselves. On the other hand, transcripts containing the intergenic regions could not be detected by Northern analysis or in vivo labelling experiments. We conclude that putative transcripts from the intergenic regions have a half-life of less than one minute. These results suggest that the tubulin gene cluster is transcribed as a single contiguous transcription unit yielding a primary transcript which is rapidly processed into individual mRNAs by the polyadenylation and mini-exon trans splicing machineries.