Discovering ADPKD Modifier Genes and Therapies via Zebrafish Genetics

Mayo Clinic Rochester, Rochester MN

Investigators

Abstract

ADPKD patients exhibit highly variable phenotypes, of which genetic modifiers were thought to play an important role. However, the identity of the genetic modifiers remains largely unknown, because of the lack of an efficient method. In this context, here, we propose to establish adult zebrafish as a new animal model that enables rapid and systematic discovery of genetic modifiers of ADPKD. We have generated substantial preliminary data for this proposal: 1) proving the molecular conservation of the zebrafish model by identifying corresponding homologues for 99% of the 82 PKD-associated genes; 2) developing zebrafish mutants for pkd1, pkd2 and ift140, 3 of the 6 known ADPKD-associated genes, which all lead to renal cyst formation; 3) demonstrating the feasibility of utilizing a novel microhomology-mediated end joining (MMEJ)-based F0 genetic method for screening ADPKD modifier genes. These preliminary data prompted us to raise a central hypothesis predicting that zebrafish is a conserved and efficient in vivo vertebrate model for discovering genetic modifiers of ADPKD. To test this hypothesis, we proposed the following three specific aims. In Aim 1, we will further prove the feasibility of our strategy by validating 2 novel protective ADPKD modifiers emerged from a MMEJ-based pilot F0 genetic screen. In Aim 2, we will explore the feasibility of using zebrafish models to assess ADPKD modifiers suggested from human patient population. In Aim 3, we will facilitate the use of zebrafish for PKD studies by further developing NMR protocols for the measurement of zebrafish kidney volume and cysts. Upon completion of the proposal, we anticipate to significantly strengthen the parent proposal, aiming to establish a F0-based genetic screen approach for systematically identifying new modifier genes for ADPKD. The launch of this novel animal model is expected to significantly advance the ADPKD field.