Cell adhesion to extracellular matrix in normal Rana pipiens gastrulae and in arrested hybrid gastrulae Rana pipiens ♀ × Rana esculenta ♂

摘要

RanapipienseggsfertilizedbyRanaesculentasperm(ESC)hybridembryosdevelopuntilgastrulationincontrolRanapipiensembryos(PIP)andthenshowmorphogeneticarrest.Afterarrest,ESCdonotgastrulatebutlivefor5daysasblastula-likeembryos.Westudiedthedistributionoffibronectin(FN)-containingfibrilsandintegrin(INT)inPIPandESC.TherearemanyFN-fibrilsinPIPorganizedinanastomosingnetworksradiatingawayfromthecenterofindividualcellsandacrossintercellularboundaries.ESChavefewerfibrilscomparedtoPIP.Thesefibrilsarefirstlocatedbetweencellsindisorganizedarrays.AfterarrestinESC,whenPIPareStage14neurulae,manymoreFN-fibrilsappear.INT-stainingoccursinbothembryosinsimilarpatterns.Inxenoplastictransplantations,wefoundthattheextracellularmatrixontheinnersurfaceoftheESCblastocoelroofservesasasubstratumforPIPcellmigration.Inaninvitroassay,wefoundmorecelladhesiontoFN-substratainPIPthaninESC.CelllocomotionratesonFN-substratawere1.70?±0.85??m/minforPIPbutonly0.46?±0.56??m/minforESC.WealsofoundthattheinnersurfaceoftheblastocoelrooffromESCcannotpromotecelladhesionandlocomotionwhenStage11fragmentsareusedforconditioningbutthatStage14fragmentscandepositaFN-fibril-richextracellularmatrixwhichsupportsPIPmesodermalcellmigrationatarateof1.26?±0.38??m/min.