Gastrulation - izo ... Mapangidwe Mipikisano magawo Ndisanaumbidwe

Blastula umatchedwanso germinal kuwira, ndi chifukwa komaliza onongani mazira. sitepe yotsatira pambuyo pake, ali ndi udindo wapakatikati pakati kuphwanya ndi organogenesis, embryogenesis ndi gastrulation. Tanthauzo lakuti mapangidwe atatu zigawo nyongolosi: endoderm, ectoderm ndi mesoderm. Mu mawu ena, gastrulation akuyamba ndi morphogenesis embryonic ndipo zosiyanasiyana za chamoyo.

Tanthawuzo la "gastrulation"

Ngakhale kumbuyo mu 1901 gastrulation amamutchula kuti ndi njira imene mwana wosabadwayo mkati kugwa mesoderm, endoderm ndi ectoderm maselo. tanthauzo limeneli kuli malo apadera blastula organoobrazuyuschih. Pozindikira ndi malongosoledwe okongola yosavuta, n'zosavuta kusamukira ku zovuta zambiri, tanthauzo masiku ano akuti. Gastrulation - ndi mndandanda wa kayendedwe morphogenetic zomwe zimadzetsa kayendedwe ka zoyamba za nsalu mu malo awoawo mogwirizana ndi "dongosolo" wa gulu la thupi. Ndondomeko kusintha zovuta ali limodzi ndi kukula ndi kubereka, kayendedwe mbali ndi zosiyanasiyana maselo.

Poganizira gastrulation m'njira inanso ambiri, akhoza mtima sitepe mungafike, za thupi limodzi zazikulu ndondomeko, imene rearrangement zigawo blastula, amene kwambiri facilitates ndondomeko ya kusintha kwa organogenesis.

Kupita maselo

Ngati mupereka ikulongosola ambiri mwa ndondomeko pansi kulingalira, tikhoza kunena kuti gastrulation - izo embolism ndi epiboly. Onse mawu kusonyeza molongosoka morphogenetic maselo, kumene kumachitika mwamtheradi pamisinkhu zonse za chitukuko ontogenetic wa chamoyo. Komabe, amapezeka kutchulidwa pamene gastrulation. Epiboly otchedwa ndondomeko kusamukira pamwamba pa phata khungu, ndipo embolism - m'gulu lawo mkati.

Mu embryology kusiyanitsa zotsatirazi mitundu ikuluikulu ya gastrulation kapena kuyenda selo: intussusception, m'dziko, involution, delamination ndi epiboly. Kuti mudziwe zambiri za iwo - Patapita nkhaniyi.

Kupita zigawo selo

Nawo ndondomeko za gastrulation silingakhoze kokha kupatukana (amasamukira momasuka) maselo, koma mapepala lonse selo. malangizo watsimikiza ndi zonse lakutali ankachita. Magulu oyamba anatsegula P. weiss, wopangidwa mu 20s Mu zaka zapitazo ndipo mlandu akuoneka ngati embryogenesis, wachiwiri - ochepa chabe wapadera, mu yachibadwa morphogenesis zimachitika ndi Mwina otsika.

Pamene gastrulation selo kugawikana amapezeka. Monga tanenera kale pamwambapa, kayendedwe akuyamba ndi misa khungu chifukwa cha mapangidwe awiri wosanjikiza embryonic otchedwa gastrula. Khalani kuoneka bwino endoderm ndi ectoderm. Zonse zamoyo multicellular (kupatula coelenterates yekha) gastrulation kufanana kapena nthawi yomweyo pambuyo aumbike germinal lachitatu tsamba otchedwa mesoderm. Ndi mndandanda wa maselo lili pakati pa endoderm ndi ectoderm. Chifukwa, Ndisanaumbidwe amakhala atatu wosanjikiza.

Njira gastrulation mwachindunji amadalira mtundu wa blastula.

invaginated gastrula

njira dzina odziwikiratu. Intussusception - limodzi wosanjikiza khoma invagination wa blastula (balstodermy) mkati blastocoel lapansi. The ambiri wosazindikira ndi chitsanzo odziwika ndi mphira mpira. Mwa kuwonekera pa zinthu izo mbamuikha mkati. Invagination akhoza kubweretsa khoma lakutali kapena kuti zonyozeka. Chifukwa ndi kusintha kwa blastula ndi gastrula analandira monga wapawiri wosanjikiza thumba archenteron. mpanda wake wamkati ndi endoderm pulayimale ndi akunja - pulayimale ectoderm. Chifukwa mmene archenteron (chachikulu intestine) amalankhulira ndi kunja mwa mabowo, wotchedwa blastopore. dzina lake chachiwiri - pakamwa chachikulu. chitukuko zina zimadalira mtundu wa chamoyo. Nyama zambiri blastopore kenako n'kukhala pakamwa okhazikika. Pa nkhani imeneyi, iwo adachemera protostomes (molluscs, nyongolotsi, arthropods). Pa deuterostome blastopore anatembenukira kwa neuro-m'mimba ritsa oyenerera mu gawo kumbuyo kwa mwana wosabadwayo (mu chordates) kapena chotulukira.

m'dziko gastrula

Immigration gastrulation - njira ya n'kupanga wosanjikiza awiri a mwana wosabadwayo, ndi khalidwe ambiri coelenterates. Gastrula aumbike mwa mbali mu blastocoel maselo blastula. m'dziko Izi unipolar m'chilengedwe. Maselo kusuntha yekha ndi mzati vegetal. Kenako iwo apanga endoderm, T. E. Wosanjikiza lamkati. Umu ndi mmene gastrulation kukuchitika pakubweranso hydroids modabwitsa.

blastoderm maselo mu blastocoel akhoza kulowa kapena dera wina, koma pa Ndisanaumbidwe padziko lonse. m'dziko limeneli linkatchedwa multipolar, koma napeza yosowa kwambiri.

coelenterates ambiri, ndiwo ogwera m'dziko njira gastrulation amapezeka wokangalika "kuchotsedwa" maselo blastula ndi gastrula, anapanga chifukwa, wotaya blastocoel. Pankhaniyi, khalidwe kwa njira yapita invaginated blastopore olumikizidwa ku makina.

Delaminatsionnaya gastrula

Izi mitundu osowa anafotokozedwa koyamba gastrula Mechnikovym I. I., ndipo lililonse kwa coelenterates lapansi. M'munsili njira gastrulation ali achirendo kwambiri, koma zazindikirika kosavuta pamene kukambirana nkhani imodzi. Mwachitsanzo, mazira a ena stsifomeduz Zigawo concentric ndi bwino yosiyanasiyana ya cytoplasm kuti: wandiweyani ndi grainy (ectoplasm) ndi ma (endoplasma). Iwo yodziwika ndi ndi yunifolomu ndi synchronous kugawikana: 2, 4; 8, 16. Pamapeto pake nyongolosi lili 32 blastomere. Komanso, magawano imagwiridwa kufanana pamwamba pa mwana wosabadwayo lapansi. Wosanjikiza akunja anapanga blastomeres ongokhala ectoplasm ndi mkati - mbali ya ectoplasm ndi endoplasmic. Mu mawu ena, multilayer nucleation zimachitika mwa komanso yogawanika wosanjikiza umodzi m'zipinda awiri. Ndiye okha blastomeres mkati wosweka ndi kachiwiri ikufanana pamwamba pa mwana wosabadwayo, ndilo chifukwa cha mtundu zoterozo gastrulation amapeza mawonekedwe ozungulira. Amakhala lathyathyathya 64 n'kupanga maselo ectoderm 32 ndi otukukira kunja, zomwe ndi maziko endoderm.

Epibolicheskaya gastrula

Nyama ndi kutchulidwa telolecithal kapangidwe ka mazira (yolk kuchepetsa kuti mzati vegetal), gastrulation amapezeka epibolicheskomu mafashoni. Macromers ndi blastomeres lalikulu kugawanitsa pang'onopang'ono ndipo muli wambirimbiri yolk lapansi. Zilibe mphamvu kusuntha, pankhani imeneyi, iwo kwenikweni "kukwawa" micromeres yogwira ili pamwamba selo. Ndi gastrulation ngati blastopore kwina ndi archenteron osati anapanga. Kenaka, pamene macromers koma yafupika kukula, izo amayamba M'mimbamo, nyongolosi ya matumbo chachikulu.

involution

Involutional gastrulation - ndondomeko imene imakhala mu "kuvumbula" maselo lakunja m'kati Ndisanaumbidwe mapangidwe. Iye kukula kukula, chimafikira pamodzi pamwamba lamkati. Njira imeneyi ndi khalidwe la nyama gastrulation mezoletsitalnymi ndi mazira - Amphibia (achule). Sunthani kutsogolera m'mphepete dera maselo kwambiri kumabwezera mmbuyo ndi archenteron chitukuko. Mu mwagona mphamvu ya involution galimoto.

Obwerawa akafuna gastrulation

Monga amadziwika, embryogenesis - ndi nthawi loyambirira la chitukuko cha aliyense chamoyo munthu ku lingaliro kubadwa. Gastrulation ndi imodzi mwa magawo ake, mbiri chachiwiri pambuyo onongani. njira zake ndi zosiyana kuti akhale poyerekeza ndi ufulu wosankha wa conditionality. Aliyense wa amenewa amafuna kuphunzira zambiri ndi kusanthula. Komabe, pali mzere ena a mphambano pakati pa awiri. Choncho, ngati mtundu wa chimake angathe kuonedwa invagination ndondomeko epiboly ndi delamination ali kufanana ndi m'dziko.

Taonani kuti nyama zambiri gastrulation ndi njira kuphatikiza. Zikatero zimachitika nthawi imodzi epiboly ndi intussusception, ndi njira zina morphogenetic. Makamaka zimakhala gastrulation amapezeka achule. Pa nkhani imeneyi, olemba ambiri kudziwa njira losanganikirana.

gastrula

Kwenikweni Latin akuti "gastrula" likumasuliridwa kuti "m'mimba, m'mimba". Bwaloli siteji yeniyeni ya embryonic chitukuko cha zamoyo multicellular. Chinthu chapadera cha gastrula ndi - ndi pamaso pa zigawo ziwiri kapena zitatu nyongolosi. The ndondomeko ya mapangidwe ake - gawo la gastrulation.

The chipangizo losavuta amakuona kwa anthu a coelenterates nyama. Iwo yodziwika gastrula ellipsoidal mawonekedwe ndi wosanjikiza unicellular akunja (ectoderm) ndipo kudzikundikira mkati mwa maselo (endoderm), ndi "m'matumbo chachikulu". Chitsanzo ankaona gastrula kanyama, amene aumbike mwa invagination. Munthu gastrulation zikuchitika pa 8-9 tsiku TH chitukuko. Gastrula ndi flattened litayamba ngati mapangidwe anapanga ku misa m'kati mwake.

Monga ulamuliro, ambiri a nyama gastrula siteji Ndisanaumbidwe ndi ufulu ndi m'mimba, kapena nembanemba dzira. Komabe, pali kuchotserapo. Choncho, mphutsi coelenterates planuly kuimira ufulu gastrula.