Embryo Transfer in the Rat as a Tool to Determine Genetic Components of the Gestational Environment

摘要

Embryotransfer,withtherecipientdamnursingthetransferredprogeny,wasusedtostudytheimpactofthegestationalenvironmentonadultbloodpressure(BP)inthreeinbredratstrains,thehypertensiveDahlsalt-sensitiveSS/JrCtr,thenormotensiveDahlsalt-hypertensionresistantSR/Jr,andthenormotensiveDarkAgoutirat.Ratsthathadbeencross-fosteredwithin6hofbirthwereincludedasacontrolforlactationalandnurturingfactors.SystolicBPwasmeasuredbytail-cuffplethysmographytwiceaweekinratsaftertheageof7weeks.Embryotransfersuccess,measuredasthepercentageofembryostransferredresultinginpupsweanedat4weeks,was27%betweentheSS/JrCtrandSR/Jrand53%fortheSS/JrCtrandDarkAgouti.Thisassessmentincludedallfailures,someofwhichprobablywerenotassociatedwiththetransfer.Ifonlythenumberofembryostransferredtodamswithsuccessfulpregnancieswasincluded,thesuccessratewas48%betweentheSS/JrCtrandSR/Jrand82%betweentheSS/JrCtrandDarkAgoutistrains.Anomaliesinpupswerenotevident.brxmlns="http://pub2web.metastore.ingenta.coms/"/brIncontrasttothelactationalenvironment,thegestationalmilieuhadaprofoundeffectonbasalbloodpressureofthehypertensiveSS/JrCtrprogeny,lessofaneffectonthatoftheDarkAgouti,andnoeffectonthatoftheSR/Jr.AlthoughtheSS/JrCtrstrainissignificantlylargerthantheSR/JrandDarkAgoutistrains,neitherembryotransfernorcross-fosteringalteredbodyweightofratsattheageof6weeks.Thesedataindicatethatembryotransfercanbeaneasyandefficientmethodofisolatinggeneticallydeterminedfactorsofthegestationalenvironment.