Open AccessAn oocyte-expressed α-Dublin gene inXenopus laevis, sequences required for the initiation of transcription
Author(s) -
Kim Middleton,
Garry T. Morgan
Publication year - 1989
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/17.13.5041
Subject(s) - biology , xenopus , microbiology and biotechnology , transcription (linguistics) , gene , promoter , dna , oocyte , response element , gene expression , genetics , embryo , linguistics , philosophy
We have studied the expression of X alpha T14, a member of the alpha-tubulin multigene family in Xenopus laevis. Small amounts of X alpha T14 RNA are detectable in a range of cell types, but much higher levels are present in ovary and tissue culture cells. In oocytes X alpha T14 transcripts accumulate during early vitellogenesis but their level declines in more advanced stages. Faithful and efficient initiation of transcription occurred on cloned X alpha T14 injected into oocytes even at low template levels. We have examined the amount of transcript produced by various deletion mutants relative to a co-injected control gene. The presence of 200bp of DNA 5' and 53bp of DNA 3' to the initiation site sufficed for high levels of promoter activity, although maximum activity required 560 bp of 5' flanking DNA. The DNA between -200 and -60 was necessary for transcription in oocytes and contains several sequence motifs implicated in transcriptional regulation including three CCAAT boxes and a sequence resembling a heat shock element. An 8 bp deletion that removed the latter element from 5kb of 5'-flanking DNA reduced promoter activity by 60%.