MOLECULAR-CLONING OF A BOVINE ORNITHINE DECARBOXYLASE CDNA AND ITS USE IN THE DETECTION OF RESTRICTION-FRAGMENT-LENGTH-POLYMORPHISMS IN HOLSTEINS

A cDNA coding for ornithine decarboxylase (ODC) was isolated from a bo vine liver cDNA library. The clone (1758 base pairs) consisted of 5'- and 3'-untranslated regions of 185 and 187 nucleotides, respectively, and an open reading frame of 1383 nucleotides encoding an ODC protein (M(r) 51 342 daltons) of 461 amino acids. Comparison of the nucleotide and the predicted amino acid of the cDNA with other mammalian ODCs sh owed a very high degree of homology both at the DNA and protein levels . The bovine ODC mRNA was identified by northern blot to be a single s pecies with a molecular size of 2.35 kilobase pairs. Primer extension analysis indicated that the 5'-untranslated region of the bovine ODC m RNA was 312 nucleotides long. Southern blot analysis of bovine genomic DNA revealed restriction fragment length polymorphisms when cleaved w ith restriction enzymes PstI, MspI, TaqI, and BglI.