Preparatory studies to enable generation of a genetically engineered marmoset as a model system for Prader-Willi syndrome

Funding Summary

Drs. Urban and Parker will examine genomic data from marmosets to lay the groundwork for the potential development of a novel animal model of PWS. The feasibility of generating a genetically engineered marmoset model for PWS will be evaluated and a detailed plan for generating this model will be generated.  

Lay Abstract

Prader-Willi syndrome (PWS) is a genetic neurodevelopmental disorder with insufficient treatment options. A marmoset model of PWS (specifically, a CRISPR-generated deletion of the PWS locus in Callithrix jacchus) would provide an ideal model system by which to study the genetic basis of normal and abnormal brain development, integrated over multiple levels of analysis, as well as translational efforts, e.g. for ‘fast-fail’ drug screening purposes that would enable streamlined translation to PWS patients. The proposed preparatory studies will lay the groundwork for development of a genetically modified PWS marmoset research platform by which to interrogate—and ultimately treat—PWS in a manner not previously achievable with existing animal models. We propose a 1-Year project to lay the foundation for this PWS marmoset research platform. Specifically, we will carry out the preparatory
analyses to enable creation of a marmoset model (covering at least one of the PWS mutations but ideally several) via the newly emerging approach of cloning by nuclear transfer of somatic nuclei. This approach will consist of carrying out the desired genome engineering in somatic cells (fibroblasts) in culture, then transferring a nucleus from the resulting culture into an enucleated marmoset oocyte and bringing the resulting embryo to term. The undertaking will be enabled by a confluence of this emerging approach of cloning from somatic cells with other advanced tools, i.e., CRISPR Cas9 as well as the newly described CRISPR Cas3 (which promises to enable the generation of smaller deletions, in the range of several kbp, with a single cut), and advanced whole-genome sequencing (WGS) to make possible the introduction of allele-specific, heterozygous CRISPR cuts.