GAMETOGNESISYCICLOOVRICO

GradodeFarmacia+NHD7deSeptiembrede2015

Introduccin

http://www.youtube.com/watch?v=J_knnENhzwgg

Introduccin

MITOSIS

Sadler,2001

Gametognesis

Sadler,2001

MEIOSIS Gametognesis

Gametognesis

Divisiones meiticas anormales: fenmenos de no disyuncin

Sadler,2001

ANEUPLODIAS Gametognesis

Dnde,cundo

ycmo

tiene

lugar

laformacin

delosgametos?

Clulas germinalesprimordiales4 semana

5 semana de desarrollo

saco vitelino

Gametognesis

ModeradorNotas de la presentacinRecent work from zebrafish (Nature 421:226) suggests a major mechanism for homing PGCs to their proper position on the gonadal ridge is the chemokine SDF-1and its receptor CXCR4. The receptor was first found associated with entry of HIV into human immune cells and has since been implicated in breast cancer metastasis

Trompauterina

A m

ampolla

itsmo

infundbulo

fimbrias

Cuerpoamarillo

ovario

Orificioexternodeltero

Frnix

delavagina

miometrio

endometrioitsmo

Orificiointernodeltero

cuello

fondocuerpo

Aparato

genitalfemenino

Tbulosseminferos

Conductilloseferentes

Conductodeferente

RedtesticularRetetestis

epiddimo

Testculo,epiddimo

yconducto

deferente

Moore,Persaud,1998

Gametognesis

Gametos

masculino

yfemenino

Moore, Persaud, 1998

A B

1.Reducirelnmerodecromosomasalamitad:4623

CLULASGERMINATIVASPRIMARIASEspermatocito

primario

Ovocitoprimario

Apareamiento Intercambio Separacin 1

divisin

2

divisin

GAMETOS

DNAX2

23pCrMITOSIS

DNAX2 46pCr

23pCr

23pCr

FECUNDACIN:ESPERMATOZOIDE+OVOCITOCIGOTO(ampollatrompauterina)

Clulasomtica(DNA)

Gametognesis

Intercambiodematerialgenticoentrecromosomashomlogos:variabilidadgentica

Nmerohaploidedecromosomas(1/2deADN)

Espermatocito

primario2(22Cry1CrX)

2(22Cry1CrY)

4gametosmaduros(ESPERMATOZOIDES)

Ovocitoprimario3(22Cry1CrX)

1(22Cry1CrX)

3cuerpospolares

1gametosmaduro(OVOCITO)maduracin

maduracin

2.Modificarlaformadelasclulasgerminativas:

Espermatocito

primario:citoplasmacabeza,cuelloycola

Ovocitoprimario:Aumentagradualmentedetamao

espermiognesis

MEIOSIS Gametognesis

HIPOTLAMO

HIPFISIS

OVARIO

TERO,TROMPAS,MAMAS,

VAGINA

GnRH

FSHyLH

EstrgenosyProgesterona

CONTROLHORMONAL(CICLOOVRICO)

Cicloovrico

Carlson,2004

Cicloovrico

Ovulacin Cuerpo

lteoCuerpolteodegenerando

Hormonas

pituitarias

Hormonas

delovario

DaFasemenstrual

Faseproliferativa

FaseSecretora

Fasemenstrual

Cicloovrico

Folculoenmaduracin

ModeradorNotas de la presentacinThree different cycles: ovarian, uterine, cervicalHypothalamus releases GnRH (gonadotropin releasing hormone) - stimulates release of gonadotropins from anterior pituitary (FSH and LH)Increase in FSH does what its name implies (Follicle stimulating hormone) - 1) stimulates follicles to grow (and support cells to proliferate). Stimulates ~5-12 follicles/cycle, 2) stimulated the production of LH receptors on the surface of granulosa cells, Thecal cells also have a small # of LH receptors - do not increase in response to FSH.Pituitary begins to release a small amount of LH which initially binds to LH receptors on thecal cells and stimulated the production of testosterone which is converted in granulosa cells to 17-b estradiol (human form of estrogen).

This ovarian hormone(estrogen) in turn 1) affects the cervix by inducing proliferation of cells of the uterine wall and thinning the cervical mucosa (allowing sperm to enter), 2) stimulated expression of more FSH receptors on the granulosa cells, 3) feedsback on the pituitary to DECREASE the production of FSH = how one follicle winsAt low estrogen conc = inhibit LH production in the pituitaryAt hi estrogen conc = stimulates LH productionAt hi sustained estrogen levels = LH from pituitary AND feeds back to hypothalamus to induce GnRH which stimulates even more LH and stimulated FSH = = = so called LH surge --- this induces a breakage of the gap junctions between the oocyte and the granulosa cells (talk about oocyte maturation inhibitor (OMI)LH surge (really pulses) is follwed a few hours later by ovulation - looks like an inflammatory response - increase in histamine, plasminogen activator = protease, prostraglandins that stimulate contraction of the ovaryAfter ovulationLH stimulates cells remaining of the follicle to begin producing progesterone the follicle now becomes called the corpus luteum (also secretes some estrogen - mostly progesterone) proges + estro feed back and shut down production of FSH which shuts down any more follicle development ----- hence classic birth control pills/patches are a form of delivery of estrogens and progesterone. egg + corona radiata swept into uterine tube ---- open to the world

No fertilisation - C.L. degrades, no more progesterone, no more estrogen, endometrium loses blood supply and sloughs, and FSH, etc reset and prepare again

If fertilisation - oocyte finishes meiosis II and off we go. hCG produced by trophoblasts maintains C.L. etc

HIPOTLAMO

ADENOHIPOFISIS

FSH LH

FOLCULO

OVULACIN

Ovocitoprimarioreanuda1

divisinmeitica

MADURACIN

OVARIO

TROMPADEFALOPIO

FECUNDACIN

FUSINDEGAMETOSYENLAREGINDELAAMPOLLADELATROMPAUTERINA

FOLCULO

Espermatozoidesvaginaterotrompadefalopio

Ovocitoestransportadohaciaalacavidaduterina

metafaseII

Cicloovrico

Moore,Persaud,2003

Cicloovrico

CIGOTO

MRULA

SEGMENTACIN

Primerasemanadedesarrollo

Primerasemanadedesarrollo

Moore,Persaud,2003

SEGMENTACIN

Sadler,2001

Segmentacinytransportedelcigoto

Mrula cavidaduterina

Masacelularinterna:embrin

Masacelularexterna:placenta

blastocisto

Masacelularexterna:trofoblastocitotrofablasto

sincitocitotrofablasto

Masacelularinterna:embrioblastoepiblasto

hipoblastoDISCOGERMINATIVO

BILAMINAR

2

SEMANADEDESARROLLO

CavidadAmnitica(superioralepiblasto)SacoVitelino

(inferioralhipoblasto)

Segundasemanadedesarrollo

Sadler, 2001

Blastocisto:

5

dadesarrollo

Primerasemanadedesarrollo

Fasedeimplantacin:

6

dadedesarrollo

Moore,Persaud,2003

Primerasemanadedesarrollo

Sadler,2001

Segundasemanadedesarrollo

8

dadedesarrollo:

estado

bilaminar

Sadler,2001

Segundasemanadedesarrollo

9

dadedesarrollo:estado

bilaminar

lagunastrofoblsticas

Segundasemanadedesarrollo12

dadedesarrollo: mesodermoextraembrionario

Sadler,2001

Sadler,2001

13

dadedesarrollo: celomaextraembrionario vellosidadescorinicasSegundasemanadedesarrollo

Sadler,2001

Implantacin

Embarazotubrico

Sadler,2001

Implantacin

ImplantacinenelfondodesacodeDouglas

Sadler,2001Netter,1989

Implantacin

3

SEMANADEDESARROLLOGASTRULACIN

Formacindelas3hojasgerminativasdelembrin

Nduloprimitivo

Lneaprimitiva

epiblasto

DISCOGERMINATIVOTRILAMINAR

ECTODERMO

ENDODERMOMESODERMO

Terecera

semanadedesarrollo

GASTRULACIN

Terecera

semanadedesarrollo

MoorePersaud,1999

GASTRULACIN

Terecera

semanadedesarrollo

Clulasdelepiblasto

migrandoatravsdelalneaprimitivaytransformndoseen

clulasmesenquimticas

Carlson,1998

GASTRULACIN

Terecera

semanadedesarrollo

ECTODERMO:SNC,SNP,epiteliosensorial

deodo,narizyojo,piel,pelo,uasehipfisis, glndulamamaria,glndulas

sudorparasyesmaltedental.

MESODERMO:Miotoma

(tejidomuscular)Esclerotema

(cartlagoyhueso)

Dermatoma

(tejidosubcutneodelapiel)Sistemavascular(corazn,arterias,venas,vasoslinfticos

yclulassanguneasylinfticas)Sistemaurogenital(rionesygnadasexceptovejiga)BazoGlndulasSuprarrenales

ENDODERMO:RevestimientoepitelialdeltractogastrointestinalAparatorespiratorioVejigaParnquimadeltiroides,paratiroides,hgadoypncreas

RevestimientodelacavidaddeltmpanoytrompadeEustaquio

PERODOEMBRIONARIO:hasta8

SEMANA

Perodoembrionario

organognesis

Carlson,2004

Tercerasemanadedesarrollo

Estado

Trilaminar

Plegamientolateral

Sadler,2001

Cuartasemanadedesarrollo:plegamientos

Sadler,2001

Plegamientolateral

Cuartasemanadedesarrollo:plegamientos

Sadler,2001

Cuartasemanadedesarrollo:plegamientos

Plegamientorostrocaudal

Nmero de diapositiva 1Nmero de diapositiva 2Nmero de diapositiva 3Nmero de diapositiva 4Nmero de diapositiva 5Nmero de diapositiva 6Nmero de diapositiva 7Nmero de diapositiva 8Nmero de diapositiva 9Nmero de diapositiva 10Nmero de diapositiva 11Nmero de diapositiva 12Nmero de diapositiva 13Nmero de diapositiva 14Nmero de diapositiva 15Nmero de diapositiva 16Nmero de diapositiva 17Nmero de diapositiva 18Nmero de diapositiva 19Nmero de diapositiva 20Nmero de diapositiva 21Nmero de diapositiva 22Nmero de diapositiva 23Nmero de diapositiva 24Nmero de diapositiva 25Nmero de diapositiva 26Nmero de diapositiva 27Nmero de diapositiva 28Nmero de diapositiva 29Nmero de diapositiva 30Nmero de diapositiva 31Nmero de diapositiva 32Nmero de diapositiva 33Nmero de diapositiva 34Nmero de diapositiva 35Nmero de diapositiva 36Nmero de diapositiva 37Nmero de diapositiva 38Plegamiento lateralNmero de diapositiva 40Nmero de diapositiva 41