Ganglioside, protein, hexose, and sialic acid changes in the trisected optic tectum of the chick embryo☆

[摘要] Spatiotemporalchangesinmembraneconstituentsofcellsfromtheoptictectumofthechickembryowereanalyzedduringtheperiodofmaximumdifferentiationandsynaptogenesis.Eachtectumfrom6-,8-,10-,and12-dayembryoswascutintothreesubregionsalongthetopologicalgradientofdifferentiation.ElectrophoreticanalysisofproteinsrevealedanalreadycomplexpopulationbyDay6whichremainedrelativelyunchangedthroughlaterstages,withlittleifanytopologicalvariations.Incontrast,chromatographicanalysisofgangliosidesshowedanincreasinglycomplexpatternasdifferentiationproceeded,withagrowingpreponderanceofmultisialogangliosides.Totalmembraneproteinincreasedsymmetricallywithtissuemassineachsubregion.However,hexoseconcentrationandsialicacid/hexoseratiosshowedstrikinglyasymmetricaltopologicaldistributionsasearlyasDay8,andtendedtofluctuatereversiblywithinbrief(1dayorless)timeperiods.Theseresultssuggestthatduringtheperiodofmaximaldifferentiationandretino-tectalsynaptogenesisintheoptictectumofthechick,themembraneproteinpopulationremainsrelativelystableandtopologicallyinvariant,whereasthepolysaccharidechainsofmembranemacromoleculesfluctuateaccordingtotopologicalpositionanddevelopmentalstateinacomplex,relativelyrapid,andapparentlyoscillatoryfashion.

[学科分类] 生物科学（综合）