Gametogenesis and FertilizationFertilization

陳建榮陳建榮

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

GametogenesisSpermatogenesis 精子生成Oogenesis 卵子生成

Meiosis 減數分裂

Mitosis meiosis

Homologous chromosomes同源染色體

SpermatogenesisSpermatogenesis Spermatogonium Spermatogonium 精母細胞精母細胞 110 0 spermatocyte spermatocyte 初級精細胞初級精細胞 2200 spermatocyte spermatocyte Spermatid Spermatid 精細胞精細胞 SpermiogenesisSpermiogenesis 精子形成 精子形成 spermatozoonspermatozoon

Haploid chromosome(double chromatin)

Haploid chromosome(single chromatin)

SpermatogenesisSpermatogenesis

World's oldest father has 21st child at 90

SpermiogenesisSpermiogenesis 精子形成精子形成穿孔體

Mature sperm

Sperm :-Head-Neck-Tail

-Middle piece-Principal piece-End piece

5 um

Sperm Capacitation- Hyperactiviated motility

Culture medium:-Ca2+, -HCO3-, -AlbuminOr oviduct fluid

Capacitation 獲能反應

Human - 7hrRat - 1hr

Transportation of gamets: sperm Reflex ejaculationReflex ejaculation

EmissionEmission 遺洩遺洩 EjaculationEjaculation 射精射精

Semen Semen 3.5 ml3.5 ml 200-600 million sperms200-600 million sperms 2-3 mm/min (30~50 um/se2-3 mm/min (30~50 um/se

c)c) Survive < 48 h in female geSurvive < 48 h in female ge

nital tractnital tract Survive 24h in vitroSurvive 24h in vitro

• Dog: 2~3 days in vitroDog: 2~3 days in vitro

Virginal plug 陰道栓Deferentectomy 輸精管切除

Sperm activity

Sperm number:-100 million / ml-20~50 million / ml -- receivable-<10 million / ml -- sterility

OogenesisOogenesis Oogonia Oogonia mature oocytes mature oocytes Primordial folliclePrimordial follicle 原始濾泡原始濾泡

Primary oocyte + one layer folliclePrimary oocyte + one layer follicle Primary folliclePrimary follicle 初級濾泡初級濾泡

Primary oocyte + zona pelluidaPrimary oocyte + zona pelluida 透明層 透明層 + + multiple layers follicle multiple layers follicle

Secondary follicleSecondary follicle Primary oocyte + zona pellucida + multipPrimary oocyte + zona pellucida + multip

le layers follicle + antrumle layers follicle + antrum Graafian follicleGraafian follicle 成熟濾泡成熟濾泡

Primordial folliclePrimordial follicle

Primary folliclePrimary follicle

Secondary follicleSecondary follicle

Graafian follicleGraafian follicle

OogenesisOogenesis

Follicular DevelopmentFollicular Development

Primordial follicle

Primary follicle Graafian follicle

Oogenesis 卵子生成

Birth

Oocyte maturation inhibitor(OMI)

Meiosis I finish1st polar body Meiosis II begin

Meiosis II finish2nd polar body

1,700

600,0002,000,000

400-500

Meiosis I begin

World's oldest natural mother at 59

Comparison of GametesComparison of Gametes

22+X or 22+Y 22+X

Cryopreservation of gametes or embryos

依卵黃含量與分佈，將卵分為 :- 無卵黃卵 (alecithal egg): 卵黃非常少。有胎盤哺乳類屬之。- 寡卵黃或均卵黃卵 (oligolecithal, isolecithal, or homolecithal egg): 卵黃的量少，分佈均勻。無脊椎動物及脊索動物屬之。- 端卵黃 (telolecithal egg): 卵黃量多，偏於卵的一端。鳥類屬之。- 中量卵黃 (mesolecithal egg): 卵黃量中等，稍偏於一端，如蛙卵。- 中位卵黃 (centrolecithal egg): 卵黃集中於中央，昆虫卵屬之。

Abnormal gametogenesis-Nondisjunction 不分離現象-Abnormal structure

Ovulation排卵

Polytocous Monotocous

Uterus :-Fundus-Body

-Perimetrium 子宮外膜-Endometrium 子宮內膜

-Basal layer -Functional layer

-Cervix

GnRHGnRH FSH FSH LHLH EstrogenEstrogen ProgesteroneProgesterone

Reproductive Reproductive cyclescycles(Menstrual cycles)(Menstrual cycles)

月經期 增生期 黃體期 缺血期

LH surge LH surge

Ovulation Ovulation (12-(12-24 h after LH surge)24 h after LH surge)

Corpus luteumCorpus luteum formed formed

Secretory phase of endoSecretory phase of endometriummetrium

Estrus cycle: 發情週期-Follicular phase 濾泡期

-Proestrus 發情前期-濾泡開始發育

-Estrus 發情期-子宮內膜充血及水腫，並分泌帶血黏液 ( 狗 )

-Luteal phase 黃體期-Metestrus 發情後期

-排卵後黃體開始發育 -Diestrus 發情間期

-黃體發育成熟 -Aestrus phase 非發情期

-有的動物並無此期。狗的非發情期約半年。

Ovulation of dog: 發情期前後均有，平均為發情前後 2 天

sexual cycle heat( 濾泡期 )pregnancy(day) ──────────────────────── dog 2/year 3w 63(58-66) cat 2-3/year 1w 60-61 pig 21d 3-5d 115 cow 3w 14(2-30)h 285(281-290) sheep 3w 24-36h 149 goat 3w 48h 154 horse 21d(40%) 1-3d 336(310-410) 15-33d(rest) mouse(rat)5d 21 hamster 16 GP (68) rabbit 30 ────────────────────────

各 種 動 物 的 動情週 期 與 懷 孕 期

FertilizationFertilization

Zona pellucida 透明層

Disappear in late blastocyst

放射冠

Fertilization

Phase of fertilization:-Passage of sperm through corona radata-Penetration of zona pellucida-Fusion of plasma membrane of the oocyte and sperm-Completion of 2nd meiotic division and formation of female pronucleus-Formation of male pronucleus-Pronuclei fusion

Subzonal space

卵黃旁空腔

Preselection of the embryonic sex

Fertilization

Fertilization

Phase of fertilization:1. Passage of sperm through corona ra

data2. Acrosomal reaction 頭帽反應3. Passage of sperm through zona4. Fusion of cell membranes of games5. Entry of sperm into the oocyte6. Cortical reaction 皮質反應7. Extrusion of 2nd polar body8. Zonal reaction 透明層反應9. Formation of female pronucleus10. Dissolution of nuclear membrane and

decondensation of chromatin of sperm

11. Reformation of male pronucleus12. Two pronuclei migrate to central posit

ion13. Pronuclei fusion

卵黃旁空腔

Sperm Binding to the Zona

ZP3: species specific

Acrosomal reaction Cortical reaction

Block to Polyspermy: 1. Fast Block: electrical change in egg membrane; 2. Slow Block: modification of zona pellucida (cortical reaction)

Cortical reaction

Block to Polyspermy: Slow Block

Zona pellusida Ca2+

Block to Polyspermy: Fast Block

Parthenogenesis 孤雌生殖Somatic cell nuclear transfer

一將功成萬骨枯

Cell cycle:

G1 S G2 M( interphase)

M phase:-Prophase-Metaphse-Anaphase-Telophase

Mitosis 細胞分裂