A novel transforming growth factor-β superfamily member expressed in gonadal somatic cells enhances primordial germ cell and spermatogonial proliferation in rainbow trout (Oncorhynchus mykiss) ☆

摘要

Ourunderstandingofthemolecularmechanismsofprimordialgermcell(PGC)proliferationinfishisrudimentary,butitisthoughttobecontrolledbythesurroundingsomaticcells.WeassumedthatgrowthfactorsthatarespecificallyinvolvedinPGCproliferationareexpressedpredominantlyinthesurroundinggenitalridgesomaticcells.Inordertoisolatethesegrowthfactors,wecompiledacomplementaryDNA(cDNA)subtractivelibraryusingcDNAfromthegenitalridgesof40-dpfrainbowtroutembryosasthetesterandcDNAfromembryoswithoutgenitalridgesasthedriver.Thisapproachidentifiedanovelcytokine,designatedgonadalsoma-derivedgrowthfactor(GSDF),whichisamemberofthetransforminggrowthfactor(TGF)-βnbsp;superfamily.GSDFwasexpressedinthegenitalridgesomaticcellssurroundingthePGCsduringembryogenesis,andinboththegranulosaandSertolicellsatlaterstages.InhibitionofGSDFtranslationbyantisenseoligonucleotidessuppressedPGCproliferation.Moreover,isolatedtesticularcellsthatwereculturedwithrecombinantGSDFdemonstrateddose-dependentproliferationoftype-Aspermatogonia;thiseffectwascompletelyblockedbyantiserumagainstGSDF.TheseresultsdenotethatGSDF,anovelmemberoftheTGF-βnbsp;superfamily,playsanimportantroleforproliferationofPGCandspermatogonia./p/div