Activating a patient-relevant pathogenic variant of a genetically defined heart disease in a humanized pig model.

Complex diseases such as progressive cardiomyopathies are often insufficiently recapitulated in small animals or in vitro models. Large animal species such as pigs provide a valuable alternative, but constitutive genetic manipulation has not yet been applied to pigs in an effective manner, mainly due to biological and logistical limitations. Here we describe the generation of a humanized pig model for phospholamban-mediated cardiomyopathy and compare different methods for activating a pathogenic R14del mutation by Cre-mediated recombination. Both Cre treatment of pig primary cells before somatic cell nuclear transfer as well as microinjection of Cre-encoding mRNA into zygotes were similarly efficient in delivering piglets with an activated R14del mutation. Alternatively, administration of Cre-encoding adeno-associated virus into piglets was sufficient, albeit to a varying extent. Together, we describe a highly effective process to establish complex inducible genetic traits in pig and demonstrate that the lack of Cre-driver lines can be compensated by various interventions during reproduction or postnatally.