Molecular cloning and characterization of ornithine decarboxylase cDNA of the nematode Panagrellus redivivus.

In a PCR with degenerate primers encoding highly conserved amino acids within ornithine decarboxylases (ODCs) of several organisms, a fragment of the ODC gene of the free-living nematode Panagrellus redivivus was isolated. Northern blot analysis revealed a single 1.7 kb transcript in a mixed-stage population of animals. From this RNA source, a cDNA library was constructed and screened with the PCR fragment. Several cDNA clones were isolated, one of which encodes the complete 435-amino-acid ODC enzyme with a calculated molecular mass of 47.1 kDa. The P. redivivus ODC possesses 126 of the 136 highly conserved amino acids in the enzymes from fungi, invertebrates and vertebrates. Functional amino acids are conserved, suggesting that the two active sites of the P. redivivus ODC are formed at the interface of a homodimer, as described for mammalian ODCs.