Abstract # 189:

Scheduled for Monday, August 28, 2017 10:40 AM-11:00 AM: (Grand Ballroom) Oral Presentation


DEVELOPMENT OF TRANSGENIC MARMOSET MODELS OF BRAIN FUNCTION AND NEURODEGENERATIVE DISEASES

A. C. Silva
NINDS - NIH, 49 Convent Drive MSC4478, Bethesda, MD 20892-4478, USA
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     Optical monitoring of neuronal populations tagged with fluorescent calcium-sensitive molecules has become an attractive way to study brain function in vivo, particularly after the development of genetically encoded calcium indicators (GECIs). GECI molecules sense calcium influx into excitable cells. Upon calcium binding, GECI molecules fluoresce, constituting a visible marker of cellular function and activity. The most optimized family of GECIs to allow monitoring of neural activity in vivo are GCaMP, which are based on a fusion of the calcium-binding protein calmodulin with the green fluorescent protein (GFP). Of all nonhuman primates, marmosets (Callithrix jacchus), an important nonhuman primate model in neurophysiological research, are the ideal species for two-photon microscopy experiments, because of their lissencephalic cortex and thin skull. We have successfully generated transgenic marmosets that were engineered to express GCaMP molecules under control of either the CMV or the hSyn promoter. High titer lentiviral vectors were produced, and injected into embryos collected from donor females. The infected embryos were then transferred to recipient females. Eight transgenic animals were born and shown to have stable and functional GCaMP expression in several different tissues. Germline transmission of the transgene was confirmed in embryos generated from two of the founder transgenic marmosets that reached sexual maturity. These embryos were implanted into six recipient females, three of which became pregnant and gave birth to five transgenic marmosets of the F1 generation. We are also using the latest gene editing techniques, such as CRISPR/cas9, to make a marmoset model of the monogenic stroke-like disease CADASIL (Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy). We believe these transgenic marmosets will be invaluable non-human primate models in neuroscience, allowing chronic in vivo monitoring of neural activity with functional confocal and multi-photon optical microscopy imaging of intracellular calcium dynamics.