Introducing dorsoventral patterning in adult regenerating lizard tails with gene-edited embryonic neural stem cells

• Published in: Nature communications Vol. 12; no. 1; p. 6010
• Main Authors: Lozito, Thomas P., Londono, Ricardo, Sun, Aaron X., Hudnall, Megan L.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 14-10-2021; Nature Publishing Group; Nature Portfolio
• Subjects: 13/1; 13/95; 631/136/1660/1993; 631/532/489; 64; 96; 96/100; 96/106; Cartilage; Cell differentiation; CRISPR; Embryo cells; Embryogenesis; Embryonic growth stage; Embryos; Genetic modification; Hedgehog protein; Humanities and Social Sciences; Lizards; Morphology; multidisciplinary; Neural stem cells; Organs; Pattern formation; Regeneration; Roofs; Saururaceae; Science; Science (multidisciplinary); Signaling; Stem cells; Tails; Tubes
• DOI: 10.1038/s41467-021-26321-9
• EISSN: 2041-1723

Lizards regenerate amputated tails but fail to recapitulate the dorsoventral patterning achieved during embryonic development. Regenerated lizard tails form ependymal tubes (ETs) that, like embryonic tail neural tubes (NTs), induce cartilage differentiation in surrounding cells via sonic hedgehog (Shh) signaling. However, adult ETs lack characteristically roof plate-associated structures and express Shh throughout their circumferences, resulting in the formation of unpatterned cartilage tubes. Both NTs and ETs contain neural stem cells (NSCs), but only embryonic NSC populations differentiate into roof plate identities when protected from endogenous Hedgehog signaling. NSCs were isolated from parthenogenetic lizard embryos, rendered unresponsive to Hedgehog signaling via CRISPR/Cas9 gene knockout of
smoothened
(
Smo
), and implanted back into clonally-identical adults to regulate tail regeneration. Here we report that
Smo
knockout embryonic NSCs oppose cartilage formation when engrafted to adult ETs, representing an important milestone in the creation of regenerated lizard tails with dorsoventrally patterned skeletal tissues.
Organisms with regenerative capacity typically regrow organs with correct axial patterning, however, regrown lizard tails lack this feature. Here the authors used neural stem cells to induce patterning in regenerating lizard tails and rescued normal skeletal morphology.