Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Slide_Handout_20_13
Document related concepts
Transcript
Blastulation! Gap Junctions! Placentation and Maternal Recognition of Pregnancy! Inner Cell Mass! Na+! Animal Science 434! John J. Parrish! Zona Pellucida! Trophectoderm! [Na+]! H2O! Tight Junctions! Hatching! Conceptus Growth! Occurs in cow, pig and sheep! Bovine! » 9 - 11 days! Cow! • Day 15, 1-2 mm! • Day 18-19, 10-20 cm! Embryonic Area! Spherical! Equine, Ovine! » 7 - 8 days! Porcine! Tubular! Elongating! Trophoblast! » 6 days! Mare remains spherical!! Filamentous! Development of Porcine Conceptuses from Day 10 to 12! Elongated Day 15 Porcine Conceptus! 5 mm Spherical 10 mm Spherical Inner Cell Mass 15 mm Tubular 150 mm Filamentous Embryo 1! Uterine Location of Elongating Ruminant Blastocyst! Pig Intrauterine Migration! Day 5! Corpus! Luteum! Bovine and Ovine! Pig Intrauterine Migration! Pig Intrauterine Migration! Day 7! Day 12! Embryos become fixed! Trans-uterine Migration in the Mare! Begins Day 10! Fixation can occur in either horn!! Fixation on day 15 - 16! Gastrulation! Trophectoderm! Inner Cell Mass! Formation of Germ Layers! Corpus! Luteum! Transuterine migration is rare in cow and ewe!! Endoderm! Blastocoele! Cavity! 2! Gastrulation! Gastrulation! Endoderm! Endoderm! Yolk Sack! Yolk Sack! Gastrula! Gastrula! Ectoderm! Trophectoderm! Ectoderm! Extraembryonic! Coelom! Mesoderm! Yolk Sack! Endoderm! Trophectoderm (Chorion)! Endoderm! Germ Layers! Ectoderm! Mesoderm! » CNS! » Sense organs! » Mammary glands! » Sweat glands! » Skin! » Hair! » hooves! » Circulatory! » Skeletal! » Muscle! » Reproductive tracts! » Kidneys! » Urinary ducts! Endoderm! Embryonic! Ectoderm! » Digestive ! » Liver! » Lungs! » Pancreas! » Thyroid gland! » Other glands! Placenta Formation! Amniotic Folds! Extraembryonic Ceolom! Yolk Sack! Trophectoderm! Mesoderm! Chorion! Endoderm! 3! Amniotic Fold! Amnionic Cavity! Amniotic Cavity! Amnion! Uterine! Lumen! Allantois! Yolk Sack! Extraembryonic Ceolom! Allantois! Yolk Sack! Chorion! Chorion! Chorion! Amniotic Cavity! Amnion! Extraembryonic Ceolom! Carnuncle! Placental Membranes! Yolk Sack! » In birds to nourish embryo! » In mammal atrophies but source of blood cells and primordial germ cells! Amnion! Allantois Cavity! Yolk! Sack! Allantochorion! (Chorioallantois)! » Non-vascular, fluid filled! » Fluid produced by fetus! » Protective cushion! » Ruptures at birth (not breaking of water)! Cotyledon! Placental Membranes (cont.)! Allantois! » Blood vessels! » Fuses with chorion! • Allantochorion or chorioallantois! • Brings blood vessels to chorion! Maternal Recognition of Pregnancy! Chorion! » Outermost membrane! » Attachment to mother! 4! Luteal Regression! CL Status! CA! (+)! Uterine PGF2α ! CL! PGF2α! (Bovine, Ovine,! Porcine)! PGF2α (Equine)! Conceptus Secretions! • Proteins! • Steroids! Recognition of Pregnancy in the Porcine! CL Regression! • Luteolytic! • No CL support! CL Maintenance! • Antiluteolytic! » Block PGF2α effects! Filamentous Embryo! (+)! No Uterine Factor! (human)! Recognition of Pregnancy! !Mechanisms • Luteotrophic! » Stimulate progesterone production by CL! Maintained! Recognition of Pregnancy in Bovine and Ovine! Conceptus Secretions! • Interferons! • oIFN-τ! • bIFN-τ! Mechanism! • Antiluteolytic! • Inhibit oxytocin receptor synthesis! • Inhibit PGF2α synthesis! Critical Days! • Bovine - 16 to 17! • Ovine - 12 to 13! Recognition of Pregnancy in the Porcine! E2! E2! E2! PGF2α! PGF2α! PGF2α! PGF2α! E2! E2! E2! PGF2α! PGF2α! 5! Recognition of Pregnancy in the Porcine! Recognition of Pregnancy in the Mare! Conceptus Secretions! • Estradiol! E2! E2! Critical Days! PGF2α! E2! PGF2α! 11 to 12! PGF2α! E2! E2! PGF2α E2! PGF2α! Mechanism! • Antiluteolytic! » Redirect PGF2α! » Requires 2 embryos per horn! Recognition of Pregnancy in the Human! PGF2α Conceptus Secretion! • ?! Mechanism! • antiluteolytic! Critical Days! 10 to 14! Recognition of Pregnancy! Conceptus Secretes! • HCG! Mechanism! • luteotrophic! INF-τ! HCG! HCG! Critical Days! • 8 to 12! Conceptus Secretions! • Proteins! • Steroids! Estradiol! Dog and Cat! CL does not regress if not pregnant ! » no uterine effect! Psuedopregnancy! » CL last similar length as in pregnancy! Implantation! 6! Time of Implantation! Type of Implantation! Attachment to Uterus! Species! Beginning! Completion! !pig !13 !24! !cow !22 !40! !sheep !15 !28! !mare !24 - 40 !95 - 100! !human !7 - 8 !30! Superficial! » Chorion lies opposed to uterine wall! » Farm animals! Eccentric! » Chorionic sack in a uterine fold! » Rodent! Interstitial! » Embryo digests part of uterine wall! » human! Degree of Tissue Loss at Parturition! Deciduate! » Eccentric, interstitial! Shape or Distribution of Chorionic Villi! Cotelydonary - cow, sheep! Diffuse - pig, horse! » Rodent, human! Zonary - dog, cat! Indeciduate or Nondeciduate! Discoid - human! » Superficial! » Farm animals! Cotelydonary Placenta! Cotelydonary Placenta! Cow! Cow! Convex! Cotelydon (Chorion)! Ewe! Concave! Placentome! Ewe! Caruncle! 70 - 120! 90 - 100! Endometrium! 7! Day 23 Migration of Bicnucleate Cells and Formation of Syncytium Placental Attachment in Ruminant! Binucleate! Cell! Chorion Migrate and" fuse with" uterine" epithelium " Uterine Epithelium Binucleate Cell Syncytium! Capillary Fusion of" Binucleate" cells and " uterine" epithelium" Stroma Endometrial Stroma Multinucleated Cells in Uterine Epithelium (multinucleate) " Binuclear Giant Cells! Placental Lactogens (Protein Hormones) Prolactin-like activity: Stimulates Milk Synthesis 20% of fetal placenta! Not Present in Pig and Mare Invade endometrium! Source! » Placental lactogen! » Pregnancy specific protein B! • May regulate maternal metabolism to facilitate fetal growth • High levels in the last 1/3 of gestation. • High levels facilitate higher milk production. • Dairy cows have higher blood concentrations than beef cows! Pregnancy Specific Protein B! Diffuse Placenta! Horse! Unique to ruminants! Function uncertain! Pig! Has been used to detect pregnancy! » Cattle, sheep, deer ! • Can be used to detect pregnancy in cows after day 25! » Not early pregnancy factor!!!! Microcotyledons! 8! Microcotelydons! Endometrial Cups in Mare! Increase placental surface area! From both trophoblast and endometrium! Microcotelydon (Fetal)! Microcotelydon! Epithelium! 5 to 10! Form between days 35 to 60! Endometrium! Microcotelydon! (Maternal)! Endometrial Glands! Uterine Arteries! Produce equine chorionic gonadotropin (eCG, PMSG)! Sloughed off after day 60! Uterine Veins! Zonary Placenta (bitch, queen)! Discoid Placenta (human)! Cell Layers Separating Maternal and Fetal Blood! Histological Classification! Fetal! Maternal! Tissues Capillary! Endothelium! Connective! Tissue! Chorionic! Epithelium! Capillary! Endothelium! Connective! Tissue! Endometrial! Epithelium! !epithelial!chorial !syndesmo- !endothelial!chorial !chorial !hemo!hemo-! !chorial !endothelial! Maternal! endothelium !+ conn. tissue !+ epithelium !+ !+ !+ !- !+ !!- !!!- !-! !-! !-! Fetal epithelium conn. tissue endothelium !+ !+ !+ !+ !+ !+ !+ !+ !+ !-! !-! !+! !*ruminant ! !dog !cat !human ! !rat! !rabbit! Species !! !+ !+ !+ !pig !horse !ruminant! 9! Important!!!!! Fetal and maternal blood does not mix during gestation.! Mixing may occur at parturition and may result in antibodies against specific fetal blood type. Impacts future fetuses or neonates!!!! » Erythoroblastosis Fetalis – Human! • Antibodies cross placenta (Rh factor)! » Neonatal Isoerythrolysis – Cat and Horse! • Antibodies in colostrum and absorbed first 24 hr of neonate’s life ! 10!
