Human neural crest cells contribute to coat pigmentation in interspecies chimeras after in utero injection into mouse embryos

Abstract

The neural crest (NC) represents multipotent cells that arise at the interphase between ectoderm and prospective epidermis of the neurulating embryo. The NC has major clinical relevance because it is involved in both inherited and acquired developmental abnormalities. The aim of this study was to establish an experimental platform that would allow for the integration of human NC cells (hNCCs) into the gastrulating mouse embryo. NCCs were derived from pluripotent mouse, rat, and human cells and microinjected into embryonic-day-8.5 embryos. To facilitate integration of the NCCs, we used recipient embryos that carried a c-Kit mutation (W sh /W sh ), which leads to a loss of melanoblasts and thus eliminates competition from the endogenous host cells. The donor NCCs migrated along the dorsolateral migration routes in the recipient embryos. Postnatal mice derived from injected embryos displayed pigmented hair, demonstrating differentiation of the NCCs into functional melanocytes. Although the contribution of human cells to pigmentation in the host was lower than that of mouse or rat donor cells, our results indicate that hNCCs, injected in utero, can integrate into the embryo and form mature functional cells in the animal. This mouse-human chimeric platform allows for a new approach to study NC development and diseases.human neural crest cells | chimera | embryonic stem cells | melanocytes

Derivation of Pluripotent Stem Cells with In Vivo Embryonic and Extraembryonic Potency

“…To further confirm the interspecies chimerism of hEPS cells, we employed a highly sensitive mitochondrial PCR assay to quantitatively analyze the degree of integration of hEPS cells in mouse conceptuses (Cohen et al, 2016; Theunissen et al, 2016). Notably, 34.4% of recovered hEPS-cell-derived mouse embryos (41/119 recovered embryos) contained human cells (we used 1 human cell in 10,000 mouse cells as the threshold).…”

Interspecies chimeras for human stem cell research

“…For example, human glial progenitor cells transplanted into the mouse brain are able to differentiate, mature and form a neural network with the neurons of the host animal (Han et al, 2013). Other progenitor cell types, for example neural crest cells, have also been used in interspecies chimeric assays (Cohen et al, 2016). In this case, the neural crest cells were derived in vitro from human PSCs and transplanted into the mouse embryos at the appropriate location and stage of development.…”

Stem Cells, Genome Editing, and the Path to Translational Medicine

“…The donor cells, after transplanting into a developmental-stage matched host, should participate in normal embryonic development to generate functionally integrated human cells of the respective cell lineage. Using this approach, we showed that human neural crest stem cells transplanted into the gastrulating mouse embryo followed neural crest specific migration patterns and contributed to the pigment lineage in postnatal mice (Cohen et al, 2016). Importantly, genetic depletion of the host melanoblast lineage significantly increased integration of human cells, suggesting that an “empty host niche” gives donor cells a selective advantage to efficiently contribute to interspecies chimeras.…”