Protein synthesis and ultrastructure during the formation of embryonic chick lens fibers in vivo and in vitro

[摘要] Proteinsynthesisandultrastructurewerestudiedintheculturedepitheliumandintheintactlensofthe6-daychickembryo.Proteinswereexaminedbysodiumdodecylsulfate-polyacrylamidegelelectrophoresis.Thelensepitheliumsynthesizedproteinswhichrangedinmolecularweightsfrommorethan200,000tolessthan20,000.Majorspecieshadmolecularweightsofabout91,000,65,000,27,000,and20,000,withaprincipalcomponentofapproximately45,000containingabout35%ofthenewprotein.After1dayinculture,theepithelialcellsdoubledinlengthandsynthesizedasmallerproportionofproteinwithmolecularweightsofabout91,000and65,000.Approximately50%ofnewlysynthesizedproteinhadamolecularweightnear45,000.Thispatternofsynthesisremainedfor3daysinvitroasthecellselongated.Inthefibersoftheintact6-daylens,some80%ofthenewproteinhadamolecularweightofabout45,000.Fibercellformationinvivoandinvitrowasassociatedwithadecreaseinorganelledensity,aclusteringofribosomesandanalignmentoflongitudinallyorientedmicrotubulesalongthecellmembrane.Thus,cellsintheculturedlensepitheliumofthechickembryoundergochangesthatarecharacteristicofepithelialcellsdifferentiatingintolensfibers.

[学科分类] 生物科学（综合）