Genes specifically expressed in the dorsal blastopore lip(胚孔唇 Spemann organizer)of the gastrula(原肠胚) were cloned. ben--CDNA library Organizer-specific Genes dissected dorsal lip st 10 y4 gastrulaFig. 4a Genes specifically expressed in the dorsal blastopore lip (胚孔唇Spemann organizer) of the gastrula（原肠胚）were cloned. Organizer-specific Genes