Cell Lineage, Axis Formation, and the Origin of Germ Layers in the Amphipod Crustacean Orchestia cavimana

Developmental Biology

Gerhard Scholtz¹  Carsten Wolff¹ 

[1] Humboldt-Universität zu Berlin, Institut für Biologie/Vergleichende Zoologie, Philippstrasse 13, 10115, Berlin, Germany

关键词: Arthropoda;    Malacostraca;    germ band;    mesoderm;    ectoderm;    cell fate;    spiral cleavage;    superficial cleavage;   

DOI  :  10.1006/dbio.2002.0789

学科分类：生物科学（综合）

来源: Academic Press

【 摘 要 】

EmbryosoftheamphipodcrustaceanOrchestiacavimanaareexaminedduringcleavage,gastrulation,andsegmentationbyusinginvivolabelling.Singleblastomeresofthe8-and16-cellstageswerelabelledwithDiItotracecelllineages.Earlycleavagefollowsadistinctpatternandthea/pandd/vbodyaxesarealreadydeterminedatthe4-and8-cellstages,respectively.Inthesestages,thegerminalrudimentandthenaupliarmesodermcanbetracedbacktoasingleblastomereeach.Inaddition,theectodermandthepostnaupliarmesodermareseparatedintorightandleftcomponents.Atthe16-cellstage,naupliarectodermisdividedfromthepostnaupliarectoderm,andextraembryoniclineagesareseparatedfrompostnaupliarmesodermandendoderm.Fromourinvestigation,itisevidentthatthecleavagepatternandcelllineageofOrchestiacavimanaarenotofthespiraltype.Furthermore,theresultsofthelabellingshowmanydifferencestocleavagepatternsandcelllineagesinothercrustaceans,inparticular,otherMalacostraca.ThecleavageandcelllineagepatternsoftheamphipodOrchestiaarecertainlyderivedwithinMalacostraca,whoseancestralcleavagemodewasmostlikelyofthesuperficialtype.Ontheotherhand,Orchestiaexhibitsastereotypedcelldivisionpatternduringformationanddifferentiationofthegermbandthatistypicalformalacostracans.Hence,aderived(apomorphic)earlycleavagepatternistheontogeneticbasisforanevolutionarilyoldercelldivisionpatternofadvanceddevelopmentalstages.O.cavimanaoffersthepossibilitytotracethelineagesandthefatesofcellsfromearlydevelopmentalstagesuptotheformationofsegmentalstructures,includingneurogenesisatalevelofresolutionthatisnotmatchedbyanyotherarthropodsystem.

【 授权许可】

Unknown