Open AccessStructural variation among human beta-tubulin genes.
Author(s) -
Nicholas J. Cowan,
C. Deborah Wilde,
Louise T. Chow,
F C Wefald
Publication year - 1981
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.78.8.4877
Subject(s) - biology , ecori , pseudogene , microbiology and biotechnology , complementary dna , southern blot , genetics , gene , cdna library , repeated sequence , restriction enzyme , genome
A chicken beta-tubulin cDNA probe has been used to screen two independently generated human genomic libraries. Of 13 EcoRI fragments detectable in a human genomic Southern blot experiment, 7 correspond in size to EcoRI fragments isolated from recombinant bacteriophage. The location of beta-tubulin-specific regions and the direction of transcription were determined within each cloned fragment. One clone (5 beta) contained a beta-tubulin-specific region of 6.8 kilobase pairs (kbp) that included three intervening sequences as well as a number of inverted repeat structures. The remaining clones contained beta-tubulin-specific sequences that were close to or, in two cases, substantially less than 1.9 kbp long. Because mature human beta-tubulin mRNA is approximately 1.9 kbp long, these short DNA regions cannot on their own encode a functional beta-tubulin mRNA. Analysis using 3'- and 5'-specific probes derived from the chicken cDNA clone showed the presence of both of these end regions within one truncated tubulin-like sequence. A second short tubulin-specific region failed to hybridize with a 3'-specific probe. These short sequences are therefore likely to be examples of pseudogenes that have arisen by loss of a portion of DNA essential to the production of functional human beta-tubulin mRNA.