Confirmation of germline transmission in GCaMP transgenic marmosets. Bright field images (A, B) and corresponding epifluorescence images (A’, B’) of F1 embryos obtained by collecting oocytes from founder marmoset TG-Y (A-A’, CMV-GCaMP5g) or from founder marmoset TG-E (B-B’, CMV-mKO-GCaMP6s) (Park et al., 2016). The oocytes were matured (IVM) and fertilized (IVF) in vitro using sperm from a wild-type marmoset. Some of the resulting embryos expressed GCaMP5g (A’, arrowheads) or GCaMP6s (B’, arrowheads) and were selected for embryo transfer into surrogate females. Wild-type embryos are shown as a control for fluorescence (A-A’, B-B’, arrows). Successful surrogate pregnancies were carried out to term and F1 transgenic marmosets were born. From founder marmoset TG-E (CMV-mKO-GCaMP6s): marmosets TG-R (male, C) and TG-L (female, D). From founder marmoset TG-Y (CMV-GCaMP5g): marmosets TG-F (male, E) and TG-V (male, F). F1 marmoset TG-A (female, G) was obtained by using sperm collected from founder marmoset TG-L (male, hSyn-mKO-GCaMP6s) to fertilize wild-type oocytes.