A Novel Phospholipase C‐X‐domain (PLCXD) containing protein exhibits differential gene expression in the European eel ( Anguilla anguilla ) intestine following “silvering”

Abstract

Adult European eels undergo a metamorphosis where sexually immature freshwater “yellow” eels, exhibit anatomical and physiological adaptations resulting in the development of sexually maturing and migratory “silver” eels. Microarray studies investigating gene expression during this stage of development identified one cDNA with homology to the mammalian phospholipase C X-domain (PLCXD) containing gene family, which exhibited loss of intestinal expression following silvering. The eel PLCXD gene, like PLCXD proteins from all other species, contains only the X domain of the normal X and Y domains that form the catalytic active site of other PLCs. To date the functional roles of these proteins are unknown. Real time PCR analysis validated the original microarray data and showed a 60-fold increase in the expression of PLCXD mRNA in the intestine of yellow compared to silver eels. Following sequencing of the full length cDNA antibodies were developed for characterisation of protein expression. Our data suggest that PLCXD expression is essential for maintenance of the normal absorptive function of the intestine of the yellow eel but is not required in the silver eel when the fish stops eating and the role of the GI tract is limited only to osmoregulation.