Simultaneous effects of head activator on the dynamics of apical and basal regeneration in Hydra vulgaris (formerly Hydra attenuata)☆

摘要

Previousstudieshavedemonstratedthatheadactivator(HA),an11aminoacidpeptide,stimulateshead-specificdifferentiationprocessesinhydra.Additionally,HAenhancesthedifferentiationofinterstitialcellsintonervecells.ThisstudyinvestigatedtheeffectsofexogenoussyntheticHAonthedynamicsofbothapicalandbasalregenerationinapieceoftissueexcisedfromthebodycolumnoftreatedanimalswhichcomprisedone-eighthoftheoriginalanimal.ThedynamicsofapicalandbasalregenerationweremonitoredusingthemonoclonalantibodyTS19.Thisantibodybindstoapicalandbasalectodermaltissueveryearlyintheprocessofregeneration,beforemorphologicalstructuresareevident.Labelingisultimatelylocalizedtothetentaclesoftheheadandaringabovethebasaldisc.Thus,TS19isausefultoolforanalyzingthedynamicsofbothapicalandbasalpatterningprocessesinthesameregeneratesimultaneously.QuantificationofTS19positiveareasonregeneratesoveratimecourseof72hrrevealedthatHAtreatmentacceleratedandamplifiedthedynamicsofbothapicalandbasalTS19labeling.Thespecificbasaleffectwasnovelandwasdemonstratedtooccurintheabsenceofadeterminedheadindependentlyofnewnervecelldifferentiation.Itisproposedthatthebasaleffectwastheresultofgrowthfactor-likeactivityofHA.