Cloning and expression of two isoforms of guanylate cyclase C (GC-C) from the European eel (Anguilla anguilla)

Complementary DNA fragments for two isoforms of particulate guanylate cycla se C (GC-C) were cloned from the intestine of the European eel (Anguilla an guilla). Both isoforms exhibited higher nucleotide and amino acid sequence homologies to members of the GC-C family from other species than the relate d guanylate cyclase A or B (GC-A or GC-B) isoforms from the eel. Northern b lots indicated that probes for both isoforms, termed GC-C1 and GC-C2, selec tively hybridised to 4.8-kb transcripts in the intestine and the kidney. Ex pression of the GC-C2 transcript in the intestine was increased by 100% fol lowing the transfer of yellow FW-acclimated eels to SW. Likewise developmen tal maturation of yellow eels into pre-migratory silver eels resulted in a significant increase (60%) in the intestinal expression of GC-C2. No change s in expression of GC-C2 were seen in the kidney under any condition. RT-PC R indicated that the GC-C2 isoform is only expressed in anterior and mid-gu t segments in FW-acclimated yellow eels. However, expression is also extend ed to the posterior gut segment when yellow eels are acclimated to SW or fo llowing developmental transformation into silver eels. (C) 2001 Elsevier Sc ience Inc. All rights reserved.