Block to Polyspermy: Fast Block

Cortical reaction

Cleavage and implantation

陳建榮

http://web.nchu.edu.tw/pweb/users/chenjr/

Day 1 ===== Day 14

Cleavage in mammalian zygote

桑椹胚

囊胚

內細胞團或胚球層

滋養層

囊胚腔

卵裂型態 (cleavage patterns): -完全分裂 (total or holoblastic cleavage):

-哺乳類動物 ( 有胎盤哺乳類 ) 之無 ( 或寡 ) 卵黃卵屬之-部份分裂 (partial or meroblastic cleavage):

-鳥類之端卵黃卵屬之。

Mature Xenopus oocyte

完全分裂 (total or holoblastic cleavage):-Spiral cleavage-Radial cleavage

部份分裂 (partial or meroblastic cleavage):-Incomplete cleavage-Superficial cleavage

Cleavage in Zebra Fish

Monozygotic twin 同卵雙生

Estrogen 抑制受精卵向子宮移動Progesterone 加速受精卵向子宮移動

Morula stage犬 : 10-11days家畜 : 5-9 days

Implantation types 著床型態 : 依滋養層與子宮內膜之間接觸的程度，及子宮內膜的被破壞情形可分為1. 間質性著床 (interstitial implantation)

- 靈長類，囓齒類，及部分肉食動物，其胚埋入子宮內膜發育，一直到出生2. 築巢性著床 (nidation implantation) 或表面著床 (superficial implantation):

- 大多數的家畜，滋養細胞並不會破壞子宮內膜。

carnivores, ruminants, horses, and pigs

rats and mice

humans, and guinea pigs

間質性著床(interstitial)

築巢性著床(nidation)

Interstitial implantation 間質性著床 :-步驟：

-Invade 侵入-Ingestive 吞食-Digestive 消化

-E6 ~ E11-Trophoblast 滋養層

-Syncytiotrophoblast-Cytotrophoblast

-Inner cell mass (embryoblast) 胚球層 bilaminar embryonic disc 雙層胚盤

Trophoblast 滋養層 :-Cytotrophoblast 細胞滋養層 -Syncytiotrophoblast 合體滋養層

-EPF (early pregnancy factor) 早期妊娠因子-24 ～ 48hr -- 10 days-In mothernal serum

-hCG 人類絨毛性腺激素-10 days-In mother’s urine

Embryoblast (inner cell mass)Hypoblast 下胚層 (primary endoderm)

hCG corpus luteum progesterone

妊娠試驗： hCG 、 EPF

Inhibition of implantation-Diethylstibestrol” 事後丸”-RU486” 流產藥丸”

築巢性 (nidation) 或表面著床 (superficial implantation)進行方式 :- 並置 (apposition): 囊胚平均排列於子宮或子宮角腔內、雙子宮的動物如兔子則無此現象。- 黏接 (adhension): 囊胚與子宮內膜接觸，子宮內膜上皮與滋養細胞連接甚緊。- 附著 (attachment): 有蹄類的滋養細胞與子宮黏膜上皮之間形成微絨毛性指間構造。

───┬────────────────────── 動物 │開始 並置 接觸 附著 完成 ───┼────────────────────── 貓 │ 11-12 16-17 (5) 狗 │ 14-17 20-21 (4-6) 牛 │ 8-32 40-45 (13-32) 綿羊 │ 4-16 10 16 28-35 (19-24) 馬 │ 5-40 38-39 95-105 (65-90) 豬 │ 2-13 12 13-14 16-18 24-26 (13-22) 人 │ 6-7 12-13 (6) ────────────────────────── * 時間是以授精後算起。

著床開始的時期與完成的時間因動物而異

人工受孕

Intracytoplasmic sperm injectionSurrogate mothers

1. 男性不孕- 數目太少- 品質太差- 無精子

2. 女性不孕- 輸卵管阻塞- 子宮切除- 自發性流產

Intracytoplasmic sperm injection

子宮外孕 (ectopic pregnancies)

Placenta previa 前置胎盤

家畜： Antimesometrial 對子宮系膜

Human

Day 8Inner cell mass Amnion 羊膜 +Epiblast 上胚層 bilaminar disc 雙層胚盤

Hypoblast 下胚層Epiblast 上胚層

Amnoitic cavity 羊膜腔

Epiblast exocoelomic membrane 外胚腔膜 Blastocytic cavity 囊胚腔 Exocoelomic cavity 外胚腔腔室

(primary yolk sac 初級卵黃囊 )

Day 9

Extraembryonic mesoderm 胚外中胚層

Syncytiotrophoblast Lacuna 陷窩

Day 10 - 12

Extraembryonic mesoderm 胚外中胚層Extraembryonic coelomic space 胚外體空隙

Syncytiotrophoblast ↓

Endomatrial stromal cell Decidual cell 蛻膜細胞=> decidual reaction蛻膜反應

Lacunar lacunar network

Closing plug 閉鎖栓

Decidual cell 蛻膜細胞

Day 13Extraembryonic mesoderm 胚外中胚層Extraembryonic coelomic space 胚外體空隙

extraembryonic coelom 胚外體腔 Extraembryonic somatic mesoderm 胚外壁層中胚層Extraembryonic splanchnic mesoderm 胚外臟層中胚層

Chorion 絨毛膜-Extraembryonic somatic mesoderm-Cytotrophoblast-Syncytiotrophoblast

Extraembryonic coelom 胚外體腔 Chorionic cavity 絨毛膜腔

Day 14

Primary yolk sacSecondary yolk sacRemnant of primary yolk sac

Cytotrophoblast Primary chorionic villus 初級絨毛膜絨毛

Hypoblast Prechordal plate 脊索前板