Cloning and expression of guanylin from the European eel (Anguilla anguilla)

Extracts of intestinal epithelia from the European eel (Anguilla anguilla) stimulated cGMP production in the T84 human colon carcinoma cell line which suggested the presence of a guanylin-like peptide in this teleost fish. De generate oligonucleotide primers were subsequently used in RT-PCR resulting in the amplification, cloning, and sequencing of two cDNAs which represent possible 5' spliceoforms of an eel homologue of the mammalian peptide, gua nylin. Northern blotting indicated that the main site of expression of the eel peptide is in the intestine with much lower signals also detected in th e kidney. Intestinal expression of guanylin mRNA is up-regulated in both no nmigratory "yellow" and the more sexually mature, migratory "silver" eels f ollowing acclimation to the seawater environment. These results suggest tha t this peptide signalling system may play a role in osmoregulation in euryh aline teleost fish during migration between the marine and freshwater envir onments. (C) 2001 Academic Press.