Gastrulation - it ... Ukuqulunqwa Umbungu multi-sixhobo sekhombuya

Blastula, ebizwa kwakhona bubble germinal, oku kubangelwa lokugqibela yokuwela amaqanda. inyathelo elilandelayo emva kwakhe, libambe indawo oluphakathi phakathi kwe ityumza yaye organogenesis, embryogenesis na gastrulation. intsingiselo yawo esisiseko ke lokusekwa ngeengcamba ezintathu intsholongwane: endoderm, ectoderm kunye mesoderm. Ngamanye amazwi, oku gastrulation luqala morphogenesis osandul kunye nohlenga ye ephilayo.

Inkcazo "gastrulation"

Nangaloo maxesha ngo-1901 gastrulation uye wachazwa indlela apho umbungu ngaphakathi ukuwa mesoderm, endoderm kunye ectoderm iiseli. Le nkcazo kuthetha ubukho izithuba ezikhethekileyo blastula organoobrazuyuschih. Sizazi ukuba inkcazelo pretty elula, kulula ukuba bafudukele entsonkothileyo kakhulu, intsingiselo mihla le kota. Gastrulation - yinto uthotho lweentshukumo morphogenetic ukuba nesiphumo intshukumo nakhululeka kuzo iziqalelo laphu kwi ndawo ubuwasekele yona ngokungqinelana "icebo" lombutho lomzimba. utshintsho esimbaxa inkqubo zikhatshwa ukukhula kunye ukuzala, intshukumo zokukhomba kunye nohlenga kweeseli.

Xa ucinga gastrulation ngengqiqo jikelele ngakumbi, oko kumiselwa njengenyathelo eliphakathi, endingowakhe inkqubo enye onamandla, ngexesha apho amacandelo ngokutsha blastula, leyo lula kakhulu inkqubo yoguquko organogenesis.

Moving iiseli

Ukuba unike inkcazelo jikelele yenkqubo phantsi ingqalelo, ukuba uthi gastrulation - it Embolism kunye epiboly. Zombini kuveza iintshukumo morphogenetic eziseleni, nto leyo eyenzeka ngokupheleleyo kuwo onke amanqanaba uphuhliso ontogenetic yento ephilayo. Noko ke, ukuba kugqame kakhulu xa gastrulation. Epiboly ngokuba inkqubo ihamba phezu kumphezulu weseli isiqalo, yaye Embolism - intshukumo yabo ngaphakathi kuyo.

Xa embryology ukwahlula ezi ntlobo zilandelayo engundoqo gastrulation okanye intshukumo iseli: intussusception, ongenelelo, involution, delamination kunye epiboly. Ukuze ufumane inkcazelo engakumbi malunga ngazo - kamva kweli nqaku.

Moving layers cell

Thatha inxaxheba kwinkqubo gastrulation ayikwazi kuphela ukusahlula (ukuthutha ngokukhululekileyo) iiseli, kodwa iseli sheets yonke. Isalathiso na unxibelelwano ezikude ozimisele rhoqo. I imikhosi yokuqala wavula P. Weiss kwi 20 ka khulu lokugqibela leminyaka kwaye ityala kubonakala ukuba embryogenesis, owesibini - a morphogenesis enqabileyo ezizodwa, ngokwesiqhelo kwenzeka kunye okuba eliphantsi.

Xa iseli gastrulation ubé kwenzeka. Njengoko sele kukhankanyiwe ngentla apha, intshukumo iqala kunye izihlwele iseli ngenxa ukuyilwa maleko-amabini osandul ebizwa gastrula. Yibani ngokucacileyo endoderm ebonakalayo kunye ectoderm. Zonke izinto eziphilayo multicellular (ngaphandle coelenterates kuphela) gastrulation ngokunxuseneyo okanye ngoko nangoko emva kokuba ezikhandelwa germinal igqabi wesithathu ebizwa mesoderm. Le yingqokelela iiseli ephakathi endoderm kunye ectoderm. Ngenxa yoko, umbungu uba-umaleko ezintathu.

Iindlela gastrulation uxhomekeke ngqo kuhlobo blastula.

gastrula invaginated

Igama indlela obuliqilima. Intussusception - a single-inwebu udonga invagination le blastula (balstodermy) ngaphakathi blastocoel. Bubonke kakhulu kwaye mzekelo obonakalayo ibhola irabha. Ngokunqakraza kwi material sicinezelweyo ngaphakathi. Invagination kungaziswa nodonga ndiniphuthume okanye wenze kube kubi. Ngenxa yoko inguqu blastula kunye gastrula ifunyenwe njengoko ombaxa bag umaleko archenteron. udonga lwayo ngaphakathi endoderm zamabanga langaphandle - ectoderm ephambili. I apho archenteron (emathunjini zaseprayimari) ngenxa enxibelelana ngaphandle ngokusebenzisa emingxunyeni, ebizwa blastopore. Igama lakhe yesibini - emlonyeni zaseprayimari. uphuhliso wayo ozakube usaqhutywa kuxhomekeke kuhlobo eziphilayo. Kwizilwanyana ezininzi ekugqibeleni blastopore ajikwa emlonyeni esichazayo. Kulo mba, bathi protostomes (molluscs, iintshulube, arthropods). Xa deuterostome blastopore aguqulelwe neuro-wamathumbu bile zilahlwe kuyo kwinxalenye elingasemva ndiseyimbumba (in chordates) okanye empundwini.

wabavela gastrula

Ungenelelo gastrulation - indlela wokusungula maleko kabini lwe ndiseyimbumba, uphawu inkoliso coelenterates. Gastrula ukhandwa i inxaxheba kuzo blastocoel iiseli blastula. Le kwelinye unipolar ngokwendalo. Iiseli ukuhambisa kuphela kwipali vegetal. Kamva bakha endoderm, t. E. Umaleko embilwini. Leyo yindlela gastrulation ngokwenziwa hydroids jellyfish.

iiseli blastoderm kungena blastocoel kusichukumisa okanye kuyo nayiphi na indawo enye, kodwa phezu lonke umbungu komhlaba. Le wabavela kwathiwa multipolar, kodwa bafumana kakhulu inqabile.

coelenterates abaninzi, nto leyo abayinqobo kwamanye amazwe indlela gastrulation kwenzeka esebenzayo kakhulu "ukhutsho" eziseleni blastula kunye gastrula, kwasekwa ngenxa yoko, ulahlekelwa blastocoel. Kulo mzekelo, uphawu ngenxa indlela yangaphambili invaginated offline blastopore.

Delaminatsionnaya gastrula

Olu hlobo ezinqabileyo kuqala wachaza gastrula Mechnikovym I. I., kwaye ekuso ukuba coelenterates. Neenkqubo ezihamba gastrulation abantu abayinqobo kakhulu, kodwa ndakala lula xa ucinga ityala esiveza. Ngokomzekelo, amaqanda ezinye stsifomeduz izabelo concentric kwaye kakuhle ezahlukahlukeneyo kukho icytoplasm: exineneyo grainy (ectoplasm) kunye zeselula (endoplasma). Bona lubonakala ngokuba ukwahlulwa efanayo kwaye yolunye: 2, 4, 8, 16. Ekugqibeleni intsholongwane iqulethe 32 blastomere. Ngaphezu koko, eli candelo liza kwenziwa ngaxeshanye kumphezulu mbungu. An zangaphandle wabumba blastomeres eyenziwa ectoplasm kunye zangaphakathi - wengxenye ectoplasm kunye endoplasmic. Ngamanye amagama, inkqubo nucleation multilayer kukuba ngokwahlula umaleko ube mnye zibe ezimbini iiseli. Emva koko, kuphela blastomeres zangaphakathi batyumkileyo kwaye kwakhona zifana nomphezulu ndiseyimbumba, nto leyo ngenxa uhlobo loo gastrulation unenxaxheba imilo ukulenza. Siqulathe tyaba 64 stem cell ectoderm 32 kunye khaxa, leyo zenza isiseko endoderm.

Epibolicheskaya gastrula

Kwizilwanyana kunye nesakhiwo ngokukhawuleza telolecithal kwamaqanda (sac lisisiqalo kwi esibondeni vegetal), gastrulation kwenzeka epibolicheskomu fashion. Macromers ezi blastomeres ezinkulu ezisahlula ngokucothayo kakhulu kwaye ziqulathe isixa enkulu sac. Awanalo ukukwazi ukuhamba, kulo mba, bona ngokoqobo "ziphume" micromeres asebenzayo ngakumbi ibekwe kwiseli komhlaba. Ekubeni gastrulation enjalo blastopore abangekhoyo kwaye archenteron ayakhekanga. Kuphela kamva, xa macromers kodwa zancitshiswa kangakanani, ukuba uqalisa ukwakha umngxuma, intsholongwane kwamathumbu zaseprayimari.

involution

gastrulation Involutional - nkqubo leyo iquka kwi "Ukuveza 'iiseli engaphandle ngaphakathi umbungu Ukwakheka. Yena luyanda ngobukhulu, kunabela ecaleni kumphezulu embilwini. Le ndlela uphawu izilwanyana gastrulation mezoletsitalnymi ngamaqanda - namasele (emanzini). Yisa phambili indawo ngohlangothi iiseli anzongonzongo abangaphangeliyo le archenteron yophuhliso. Kubo kukho eziqhuba involution.

indlela olungumxube gastrulation

Njengoko yaziwa, embryogenesis - eli xesha yokuqala kuphuhliso eziphilayo ngamnye ukusuka ekuzalweni ukuya ekuzalweni. Gastrulation yenye izigaba zawo, imbali yesibini emva obukhulu. Iindlela ezahlukeneyo ukuze babe kuthelekiswa iqondo elikhulu kwiimeko. Nganye kwezi kufuna isifundo eneenkcukacha nohlalutyo. Noko ke, kusekho umgca ethile yonqumlo phakathi kwabo bobabini. Ngenxa yoko, njengokuba uhlobo ngobuwena zingathathwa inkqubo invagination epiboly kunye delamination na ezifanayo kunye kwamanye amazwe.

Qaphela ukuba izilwanyana ezininzi gastrulation yindlela odityanisiweyo. Kwiimeko ezinjalo zenzeke ngaxeshanye epiboly kunye intussusception, kunye nezinye iinkqubo morphogenetic. Ngokukodwa, kunjalo gastrulation kwenzeka emanzini. Kulo mba, ababhali abaninzi ukuchonga indlela mixed.

gastrula

elithi "gastrula" ngokoqobo Latin liguqulelwe ngokuba 'isisu, isisu ". Iluphawu kwisigaba esithile sophuhliso osandul eziphilayo multicellular. A isici esasenza gastrula - kuba phambi lamanqanaba amabini okanye amathathu lwegciwane. Inkqubo lasungulwa - kwisigaba gastrulation.

Icebo elula lubonwa ukusuka abameli coelenterates izilwanyana. Bona ebonakala imilo gastrula ellipsoidal ngomaleko kwiseli enye engaphandle (ectoderm) kunye nokwanda lwangaphakathi iiseli (endoderm), kwaye "ethunjini zaseprayimari". Gumbini luthathwa sea gastrula, oluthi luqokelelane yi invagination. Le ndoda gastrulation lwenzeka 8-9 imini th yophuhliso. Gastrula i diski-ezifana ukubunjwa atshabalalisa wabumba kwiseli mass elingaphakathi.

Ngokuqhelekileyo, inkoliso nezilwanyana ndiseyimbumba isigaba gastrula awukwazi kuphila ngokukhululekileyo kwaye esibelekweni, okanye inwebu zamaqanda. Nangona kunjalo, kukho ukuxolelwa. Ngenxa yoko, coelenterates kwindawo planuly zimele free-gastrula.