Regeneration of neural retina from the pigmented epithelium in the chick embryo

[摘要] Theneuralretinaandlenswereremovedfromtheeyesof4-daychickembryos,whichwerethendividedintosixgroups:(a)6eyeswerefixedimmediately;(b)in17animalsa4-daylensalonewasreplaced;(c)in32casesbotha4-daylensandapieceof4-dayneuralretinawerereintroducedintotheeye;(d)in14casesa4-dayotocystwasimplanted;(e)in13casesa4-daylensandapieceof4-dayoptictectumwereimplanted;(f)in4specimensapieceof4-dayneuralretinaalonewasreintroducedintotheeye.Analysisofthesubsequentdevelopmentofthesegroupsledtothefollowingobservationsandconclusions:1.1.Neuralretinacanregeneratefromthepigmentedepitheliumofthechickembryoatleastaslateasstage24.2.2.Regenerationoccursintwoways:(a)fromthecupmargin;(b)inpatchesofpigmentedepitheliumsomedistancefromthemargin.3.3.Bothtypesofregenerationrequirethattheneuralretinabephysicallyseparatedfromthepigmentedepitheliumwithoutbeingremovedfromtheimmediateenvironment.4.4.The4-dayotocystcanelicitneuralretinalregenerationfromtheembryonicpigmentedepithelium.5.5.The4-dayoptictectumdoesnotelicitneuralretinalregenerationfromthepigmentedepithelium.6.6.Thepresenceofthelensisnotnecessaryforregenerationoftheneuralretina.7.7.Regeneratingneuralretinadifferentiatesmorerapidlythannormallydevelopingneuralretina.8.8.Thepolarityoftheregeneratingneuralretinawithrespecttotheeyeisnormalifitarisesfromthecupmargin,andreversedifitarisesinpatchesfromthepigmentedepithelium.9.9.Theaxonsoftheganglioncellsoftheregeneratingneuralretinafasciculatetoformasingle“opticnerve”whichleavestheeyeatitsposteriorpole.

[学科分类] 生物科学（综合）