Generation of a monkey with MECP2 mutations by TALEN-based gene targeting.
Ontology highlight
ABSTRACT:
SUBMITTER: Liu Z
PROVIDER: S-EPMC5562616 | biostudies-other | 2014 Jun
REPOSITORIES: biostudies-other
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Project description:We report Transcription Activator-like Effector Nucleases (TALEN)-mediated mutagenesis of the Rett Syndrome gene, methyl-CpG binding protein 2 (Mecp2), in nonhuman primates (NHPs). Microinjection of Mecp2-targeting TALEN plasmids into rhesus and cynomolgus zygotes caused 40-50% of the embryos harboring mutations when examined beyond 8-cell stage. The surrogate pregnancy rates were 28.6% (2/7) and 16.7% (1/6) for rhesus and cynomolgus, respectively. The 2 rhesus surrogates went through miscarriage at 30- and 63/64-days of gestation. Analyses of two 63/64-day-old liter-mate embryos indicated both were male and carried MeCP2 mutations, yet chimeric. Mutation rate was higher in one embryonic brain than the other. RNA sequencing and anatomical analyses indicated that the brain with higher-degree mutations was underdeveloped, which, together with mid-gestation-stage male lethality likely recapitulate the disease. One live delivery of a female cynomolgus monkey occurred after 162 days of gestation, with abundant mutagenesis in peripheral tissues examined. We conclude that TALEN-mediated mutagenesis greatly facilitates disease modeling in NHPs.
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Project description:Gene-editing technologies have made it feasible to create nonhuman primate models for human genetic disorders. Here, we report detailed genotypes and phenotypes of TALEN-edited MECP2 mutant cynomolgus monkeys serving as a model for a neurodevelopmental disorder, Rett syndrome (RTT), which is caused by loss-of-function mutations in the human MECP2 gene. Male mutant monkeys were embryonic lethal, reiterating that RTT is a disease of females. Through a battery of behavioral analyses, including primate-unique eye-tracking tests, in combination with brain imaging via MRI, we found a series of physiological, behavioral, and structural abnormalities resembling clinical manifestations of RTT. Moreover, blood transcriptome profiling revealed that mutant monkeys resembled RTT patients in immune gene dysregulation. Taken together, the stark similarity in phenotype and/or endophenotype between monkeys and patients suggested that gene-edited RTT founder monkeys would be of value for disease mechanistic studies as well as development of potential therapeutic interventions for RTT.
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