Germ Line Development in the Grasshopper Schistocerca gregaria: vasa As a Marker

Developmental Biology

Chun-che Chang¹  Peter Dearden¹  Michael Akam¹ 

[1] Laboratory for Development and Evolution, University Museum of Zoology, Department of Zoology, Downing Street, Cambridge, CB2 3EJ, United Kingdom

关键词: arthropod;    Orthoptera;    germ cell;    gonad;    vasa;    embryogenesis;    ovary;    testis;    antibody;   

DOI  :  10.1006/dbio.2002.0840

学科分类：生物科学（综合）

来源: Academic Press

【 摘 要 】

Vasaisawidelyconservedgermlinemarker,bothinvertebratesandinvertebrates.Weidentifyavasaorthologue,Sgvasa,anduseittostudygermlinedevelopmentinthegrasshopperSchistocercagregaria,aspeciesinwhichnogermplasmhasbeenidentified.Inadults,Sgvasaisspecificallyexpressedintheovaryandtestis.Itisexpressedathighlevelsduringearlyoogenesis,butnodetectablevasaRNAandlittleVasaproteinarepresentinmatureunlaideggs.Noneappearstobelocalizedtoanydefinedregionoftheeggcortex,suggestingthatgermlinespecificationmaynotdependonmaternalgermplasmexpressingvasa.Vasaproteinisexpressedinmostcleavageenergidsastheyreachtheeggsurfaceandpersistsathighlevelsinmostcellsaggregatingtoformtheembryonicprimordium.However,aftergastrulation,Vasaproteinpersistsonlyinextraembryonicmembranesandincellsattheoutermarginofthelateheart-stageembryo.Intheembryo,itthenbecomerestrictedtocellsatthedorsalmarginoftheformingabdomen.Inolderembryos,theseVasa-positivecellsmovetowardthemidline;Vasaproteinaccumulatesasymmetricallyintheircytoplasm,apatterncloselyresemblingthatofgermcellsinlateembryonicgonads.Thus,wesuggestthattheVasa-stainedcellsintheabdominalmarginaregermcells,asproposedbyNelson(1934),andnotcardioblasts,ashasbeenproposedbyothers.

【 授权许可】

Unknown