SEQUENCES RELATED TO THE OX PANCREATIC RIBONUCLEASE CODING REGION IN THE GENOMIC DNA OF MAMMALIAN-SPECIES

Mammalian pancreatic ribonucleases form a family of homologous protein s that has been extensively investigated. The primary structures of th ese enzymes were used to derive phylogenetic trees. These analyses ind icate that the presence of three strictly homologous enzymes in the bo vine species (the pancreatic, seminal, and cerebral ribonucleases) is due to gene duplication events which occurred during the evolution of ancestral ruminants. In this paper we present evidence that confirms t his finding and that suggests an overall structural conservation of th e putative ribonuclease genes in ruminant species. We could also demon strate that the sequences related to ox ribonuclease coding regions pr esent in genomic DNA of the giraffe species are the orthologues of the bovine genes encoding the three ribonucleases mentioned above.