An Eye Organoid Approach Identifies Six3 Suppression of R-spondin 2 as a Critical Step in Mouse Neuroretina Differentiation
Nozomu Takata,
Deepti Abbey,
Luciano Fiore,
Sandra Acosta,
Ruopeng Feng,
Hyea Jin Gil,
Alfonso Lavado,
Xin Geng,
Ashley Interiano,
Geoffrey Neale,
Mototsugu Eiraku,
Yoshiki Sasai,
Guillermo Oliver
Affiliations
Nozomu Takata
Center for Vascular and Developmental Biology, Feinberg Cardiovascular Research Institute, Northwestern University, Chicago, IL 60611, USA
Deepti Abbey
Department of Genetics, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
Luciano Fiore
Center for Vascular and Developmental Biology, Feinberg Cardiovascular Research Institute, Northwestern University, Chicago, IL 60611, USA
Sandra Acosta
Center for Vascular and Developmental Biology, Feinberg Cardiovascular Research Institute, Northwestern University, Chicago, IL 60611, USA
Ruopeng Feng
Department of Genetics, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
Hyea Jin Gil
Center for Vascular and Developmental Biology, Feinberg Cardiovascular Research Institute, Northwestern University, Chicago, IL 60611, USA
Alfonso Lavado
Department of Genetics, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
Xin Geng
Department of Genetics, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
Ashley Interiano
Department of Genetics, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
Geoffrey Neale
Hartwell Center for Bioinformatics and Biotechnology, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
Mototsugu Eiraku
Laboratory for in vitro Histogenesis, RIKEN Center for Developmental Biology, Kobe, Hyogo 650-0047, Japan; Laboratory of Developmental Systems, Institute for Frontier Life and Medical Sciences, Kyoto University, 53 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto, Kyoto 606-8507, Japan
Yoshiki Sasai
Laboratory for Organogenesis and Neurogenesis, RIKEN Center for Developmental Biology, Kobe, Hyogo 650-0047, Japan
Guillermo Oliver
Center for Vascular and Developmental Biology, Feinberg Cardiovascular Research Institute, Northwestern University, Chicago, IL 60611, USA; Corresponding author
Summary: Recent advances in self-organizing, 3-dimensional tissue cultures of embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs) provided an in vitro model that recapitulates many aspects of the in vivo developmental steps. Using Rax-GFP-expressing ESCs, newly generated Six3−/− iPSCs, and conditional null Six3delta/f;Rax-Cre ESCs, we identified Six3 repression of R-spondin 2 (Rspo2) as a required step during optic vesicle morphogenesis and neuroretina differentiation. We validated these results in vivo by showing that transient ectopic expression of Rspo2 in the anterior neural plate of transgenic mouse embryos was sufficient to inhibit neuroretina differentiation. Additionally, using a chimeric eye organoid assay, we determined that Six3 null cells exert a non-cell-autonomous repressive effect during optic vesicle formation and neuroretina differentiation. Our results further validate the organoid culture system as a reliable and fast alternative to identify and evaluate genes involved in eye morphogenesis and neuroretina differentiation in vivo. : Using an eye organoid culture system, Takata et al. identified the Wnt signaling partner R-spondin 2 as a critical player in neuroretina fate determination in vivo and in vitro. They also validated these findings using newly derived conditional null Six3delta/f;Rax-Cre ESCs from mouse blastocysts. Keywords: eye, optic vesicles, Six3, pluripotent stem cells, organoids, neuroretina, R-spondins, Wnt, mouse, Six3 conditional knockout ESCs
