Cloning of DNA complementary to bovine prolactin mRNA

We have cloned DNA complementary to mRNA coding for bovine prolactin (bPrl). Double-stranded cDNA prepared from bovine pituitary mRNA was inserted into the Pst I site of plasmid bPR322 by the dC x dG tailing technique and amplified in E. coli chi 1776. A recombinant plasmid containing bPrl cDNa was identified by hybridization to cloned rat Prl cDNA. It contains cDNA corresponding to the region of the mRNA coding for the carboxy terminal 101 amino acids of bPrl, as well as 42 nucleotides in the 3' untranslated region of the mRNA. Nucleotide sequencing confirmed the amino acid sequencing of this region of bPrl, and permitted the assignment of asparagine or glutamic acid at seven previously equivocal loci. Codon use in bPrl mRNA is comparable to that found in rat and human Prl mRNA's and differs from that in bovine, rat, and human growth hormone mRNA's.