The present invention is an in vitro method for producing isolated mammalian primitive retinal stem cells (pRSCs), comprising: (a) cells that do not contain feeder cells, feeder conditioned media or serum Culturing isolated embryonic stem cells (ESCs) from mammals in a culture medium to produce and proliferate a culture of isolated ESCs; and (b) so proliferated A culture of isolated ESCs is contacted with one or more inhibitors of Wnt or TGF-β / BMP signaling, and the isolated ESCs of (a) are differentiated into primitive retinal stem cells, thereby isolated mammals A method comprising producing pRSCs. [Selection] Figure 1本発明は、単離された哺乳動物の原始的網膜幹細胞(primitive retinal stem cells、pRSCs)を生産するためのin vitro方法であって、(a)フィーダー細胞、フィーダー馴化培地又は血清を含まない細胞培養培地中で哺乳動物由来の単離された胚性幹細胞(embryonic stem cells、ESCs)を培養し、単離ESCsの培養物を生産し、増殖させるステップ、及び(b)そのように増殖させた単離ESCsの培養物を、Wnt又はTGF-β/BMPシグナル伝達の阻害剤の1つ以上と接触させ、(a)の単離ESCsを原始的網膜幹細胞に分化させ、それによって単離哺乳動物pRSCsを生産するステップを含む、方法。【選択図】図1