title: Identification and Expression Analysis of the Complete Family of ZebrafishpkdGenes.
abstract: Polycystic kidney disease (PKD) proteins are trans-membrane proteins that have crucial roles in many aspects of vertebrate development and physiology, including the development of many organs as well as left-right patterning and taste. They can be divided into structurally-distinct PKD1-like and PKD2-like proteins and usually one PKD1-like protein forms a heteromeric polycystin complex with a PKD2-like protein. For example, PKD1 forms a complex with PKD2 and mutations in either of these proteins cause Autosomal Dominant Polycystic Kidney Disease (ADPKD), which is the most frequent potentially-lethal single-gene disorder in humans. Here, we identify the complete family ofpkdgenes in zebrafish and other teleosts. We describe the genomic locations and sequences of all seven genes:pkd1, pkd1b, pkd1l1, pkd1l2a, pkd1l2b, pkd2, andpkd2l1.pkd1l2a/pkd1l2bare likely to be ohnologs ofpkd1l2, preserved from the whole genome duplication that occurred at the base of the teleosts. However, in contrast to mammals and cartilaginous and holostei fish, teleosts lackpkd2l2, andpkdrejgenes, suggesting that these have been lost in the teleost lineage. In addition, teleost, and holostei fish have only a partialpkd1l3sequence, suggesting that this gene may be in the process of being lost in the ray-finned fish lineage. We also provide the first comprehensive description of the expression of zebrafishpkdgenes during development. In most structures we detect expression of onepkd1-like gene and onepkd2-like gene, consistent with these genes encoding a heteromeric protein complex. For example, we found thatpkd2andpkd1l1are expressed in Kupffer's vesicle andpkd1andpkd2are expressed in the developing pronephros. In the spinal cord, we show thatpkd1l2aandpkd2l1are co-expressed in KA cells. We also identify potential co-expression ofpkd1bandpkd2in the floor-plate. Interestingly, and in contrast to mouse, we observe expression of all sevenpkdgenes in regions that may correspond to taste receptors. Taken together, these results provide a crucial catalog ofpkdgenes in an important model system for elucidating cell and developmental processes and modeling human diseases and the most comprehensive analysis of embryonicpkdgene expression in any vertebrate.
authors.affiliation: Department of Biology, Syracuse University Syracuse, NY, USA.
authors.forename: Samantha J
authors.initials: SJ
authors.lastname: England
authors.affiliation: Department of Biology, Syracuse University Syracuse, NY, USA.
authors.forename: Paul C
authors.initials: PC
authors.lastname: Campbell
authors.affiliation: Department of Biology, Syracuse University Syracuse, NY, USA.
authors.forename: Santanu
authors.initials: S
authors.lastname: Banerjee
authors.affiliation: Department of Biology, Syracuse University Syracuse, NY, USA.
authors.forename: Annika J
authors.initials: AJ
authors.lastname: Swanson
authors.affiliation: Department of Biology, Syracuse University Syracuse, NY, USA.
authors.forename: Katharine E
authors.initials: KE
authors.lastname: Lewis
keywords: PKD; TRP proteins; dorsal forerunner cells; kidney; node; polycystin; spinal cord; taste buds