老鼠胚胎发育时期示意图.pdf

TheilerTheilerTheilerTheiler StageStageStageStage 1 1 1 1 - - - - One-cellOne-cellOne-cellOne-cell eggeggeggegg Fertilized one-cell stage egg (embryo), zona pellucida present (shown in red). 0-0.9 dpc (range 0-2.5) Scale bar in microns TheilerTheilerTheilerTheiler StageStageStageStage 2 2 2 2 - - - - DividingDividingDividingDividing eggeggeggegg Dividing egg stage, zona pellucida present (shown in red). First cleavage occurs at about 24 hours. 1 dpc (range 1-2.5) 2-4 cells. Scale bar in microns TheilerTheilerTheilerTheiler StageStageStageStage 3 3 3 3 - - - - MorulaMorulaMorulaMorula Four- to 16-cell stage embryos from early to fully compacted morula. Zona pellucida present (shown in red). Embryos in the oviduct towards utero-tubal junction. 2 dpc (range 1-3.5) 4-16 cells. All scale bars in microns. TheilerTheilerTheilerTheiler StageStageStageStage 4 4 4 4 - - - - BlastocystBlastocystBlastocystBlastocyst (ICM(ICM(ICM(ICM apparent)apparent)apparent)apparent) Embryo progresses from morula to the blastocyst still within the zona pellucida (shown in red). There is early evidence of the blastocoelic cavity. 3 dpc (range 2-4) 16-40compacted cells. All scale bars in microns. In the blastocyst stage (zona-intact) there is a distinct inner cell mass and an outer layer of trophectoderm cells. Usually located in the uterine lumen. TheilerTheilerTheilerTheiler StageStageStageStage 5 5 5 5 - - - - BlastocystBlastocystBlastocystBlastocyst (zona-free)(zona-free)(zona-free)(zona-free) Blastocyst (zona-free), invariably located within the uterine lumen. 4 dpc (range 3-5.5) Scale bar in microns TheilerTheilerTheilerTheiler StageStageStageStage 6 6 6 6 - - - - AttachmentAttachmentAttachmentAttachment ofofofof blastocystblastocystblastocystblastocyst Blastocysts implants, first evidence of embryonic endoderm cells covering the blastceolic surface of the inner cell mass. 4.5 dpc (range 4-5.5) Witschi Stage 8 (rat) Carnegie Stage 4 (human) Scale bar TheilerTheilerTheilerTheiler StageStageStageStage 7 7 7 7 - - - - ImplantationImplantationImplantationImplantation andandandand formationformationformationformation ofofofof EggEggEggEgg CylinderCylinderCylinderCylinder Ectoplacental cone appears. Rapid increase in the number of inner cell mass cells leading to the formation of the epiblast with subsequent growth to form the egg cylinder. The proximal or visceral cells (opposite side from the trophoblastic cap) are cuboidal in shape. Primary endoderm lines the mural trophectoderm. 5 dpc (range 4.5-6) Witschi Stage 10 (rat) Carnegie Stage 5 (human) Scale TheilerTheilerTheilerTheiler StageStageStageStage 8 8 8 8 - - - - DifferentiationDifferentiationDifferentiationDifferentiation ofofofof eggeggeggegg cylindercylindercylindercylinder Implantation site 2x3mm. The maternal tissue is invaded by trophoblast (primary) giant cells and the ectoplacental cone is invaded by maternal blood. Differentiation of the egg cylinder into embryonic and extraembryonic regions and the formation of the proamniotic cavity. Reichert's membrane, which is non-cellular and secreted by the distal endoderm first appears. 6 dpc (range 5-6.5) Witschi Stage 10-11 (rat) Carnegie Stage 5 (human) Scale bar in microns TheilerTheilerTheilerTheiler StageStageStageStage 9 9 9 9 - - - - AdvancedAdvancedAdvancedAdvanced EndometrialEndometrialEndometrialEndometrial ReactionReactionReactionReaction PS: Advanced egg-cylinder stage with the first evidence of of an embryonic axis. There is clear morphological distinction between the embryonic and extraembryonic ectoderm. The ectoplacental cone is further invaded by maternal blood and the original lumen of the uterine crypt has disappeared. ES: Late in this stage gastrulation begins, producing the first mesodermal cells. 6.5 dpc (range 6.25-7.25) Downs neuropore;neuropore;neuropore; forelimbforelimbforelimbforelimb budbudbudbud TheTheTheThe posteriorposteriorposteriorposterior neuroporeneuroporeneuroporeneuropore formformformform andandandand thethethethe condensationcondensationcondensationcondensation ofofofof thethethethe forelimbforelimbforelimbforelimb budbudbudbud becomesbecomesbecomesbecomes apparentapparentapparentapparent nearnearnearnear thethethethe 8th-12th8th-12th8th-12th8th-12th somitesomitesomitesomite pairs.pairs.pairs.pairs. A A A A distinctdistinctdistinctdistinct condensationcondensationcondensationcondensation ofofofof thethethethe hindhindhindhind limblimblimblimb budbudbudbud appearsappearsappearsappears justjustjustjust atatatat thethethethe endendendend ofofofof thethethethe stage.stage.stage.stage. TheTheTheThe forebrainforebrainforebrainforebrain vesiclevesiclevesiclevesicle subdividessubdividessubdividessubdivides intointointointo telencephalictelencephalictelencephalictelencephalic andandandand diencephalicdiencephalicdiencephalicdiencephalic vesicles.vesicles.vesicles.vesicles. Absent:Absent:Absent:Absent: hindlimbhindlimbhindlimbhindlimb bud,bud,bud,bud, Rathke'sRathke'sRathke'sRathke's pouch.pouch.po。