The gene for the β-subunit of rat thyrotropin has been isolated from a library of rat DNA fragments cloned in bacteriophage λ. The complete nucleotide sequence of the gene has been determined including a portion of 5′- and 3′-flanking regions. The rat TSH-β gene contains approximately 4879 nucleotides which ultimately lead to the production of a mRNA of about 554 nucleotides, exclusive of the 3′ poly(A) tract. The first exon which represents only 5′ untranslated sequences of the mRNA, is separated from the second exon by a very large, 3.9-kbp intervening sequence. The second and third exons are separated by a small, 377-bp intervening sequence. Southern blot analysis of total genomic DNA demonstrated that the rat genome contains sequences similar to the cloned gene, suggesting that no rearrangements occurred during the cloning process.
ASJC Scopus subject areas
- Molecular Biology