Muka - te reira ... Whakamārama, hanganga me te mahi

wehenga muka - he hanganga rangitahi i hanga i roto i te tukanga o te whāū pūira me te whāiti pūira, me te whakarato pūira Pharoah me te wehewehenga pūtau. Reira pourua: pūnaha microtubule i hanga i roto i te wāhi i waenganui i nga amo, te āhua o te muka. Kua piri ana te rohe centromere o kinetochores pūira ki te microtubules muka. E ai ki a ia neke nga pūira ki te amo.

hanganga

ngā o toru ngā āhuatanga hanganga taketake muka: microtubules, chromosomes me wehenga o amo. Pou wehewehe nga kararehe e whakaritea mā te centrosome, e roto i centrioles. I roto i te take o nga wahi i waho centrosomes (i roto i te tipu, me te i roto i oocytes o te tahi mau momo) muka kua he pou whanui, me te huaina atsentrosomalnym. I roto i te hanganga o te muka whai wāhi ko tetahi hanganga - nekeneke pūmua. no ratou ki te dynein me kinesin.

wehenga muka - he hanganga pourua. Kei amo rua centrosomes - organelles e ko te pokapū o te whakahaere microtubule. Ko te hanganga o te centrosome wehewehe rua centrioles, e kua karapotia e te tini o pūmua rerekē. pūira i Whakapotohia he te ahua o chromatids rua tū tahi i te pae centromere, kei waenganui i nga amo. I roto i te centromeres he kinetochores, e tango tuu te tāpiritanga o microtubules.

hanganga

Mai wehenga takai miro - ko te hanganga i te kawenga mō te wehenga pūtau, timata tona whakaminenga puta i roto i te prophase. I roto i ngā tipu me te i roto i oocytes i te ngaro o centrosomes, tavini pokapū microtubule whakahaere rite te anga o te karihi. He Microtubules tata ki te kōpaki karihi, me te mutu i roto i te mutunga o prophase ratou takotoranga, ka hanga i "muka prophase" - tuaka muka heke mai.

Nā ki te meka i roto i ngā pūtau kararehe te te centrosome whai te tūranga o te whakahaere o te pokapū, te timatanga o te hanganga o te muka mitotic ko te rerekētanga i waenganui i te centrosomes e rua i roto i prophase. Ko te taea tenei te mea dynein te pūmua nekeneke e piri ratou ki te mata waho o te matua me te taha roto o te membrane pūtau. rōpū dynein piri ki te membrane, hono ki te microtubules Astral me tīmata ratou ki te neke ki te mutunga kino, e tika ana ki nei i reira he waimehatanga o centrosomes i ngā wāhi ritenga o te membrane pūtau.

Ko te mutunga o te whakaminenga

Ko te hanganga whakamutunga o te muka puta i atamira prometaphase, i muri i te ngaro o te membrane riro te reira i te matua oti, no te mea he reira ka taea riro centrosomes me microtubules uru ki nga wāhanga o te muka.
Heoi, i reira he kotahi okotahi: puta te pihi muka hanganga rewena mitotic i roto i te karihi.

miro hanganga takai miro, me to ratou takotoranga e taea waho e rua tukanga: te whakahaere o microtubules huri noa nga ngā pūira me ratou hononga ki tahi i te tahi i amo te ritenga o te wehenga. E rave rahi o te āhuatanga e tika ana mō te hanganga whakamutunga o muka, tae atu ki ngā pūira me pūmua nekeneke kitea i roto i te karihi pūtau, me microtubules me, ki te roto i te centrosomes pūtau kararehe i roto i te cytoplasm, i.e., Kei te noho taratahi te wāhanga i ia atu. Ko Ko te aha te hanganga o te muka mutu i muri anake i te ngaro o te kōpaki karihi.

hono pūira

I roto i te hanganga o te pūmua muka mitotic he wāhi, me te maha atu ngā hanganga, me kua kua pai ako tenei tukanga i roto i ngā pūtau kararehe. I roto i prophase, microtubules hanga huri noa te hanganga stellate centrosome e diverges i te ahunga toropā. I muri i te wehenga membrane karihi iho, tapepe hihiri o microtubules timata ki te tūhura mātātoa tenei rohe, me te taea te whakaritea kinetochores o pūira ki a ratou. Ētahi wāhanga o te pūira tahuri tonu i amo ritenga, me te here tuatahi toe ki microtubules tetahi o nga amo, me ka anake timata ki te neke ki te pou e tika ana. A, no te oti te tukanga e, te pūira, kua e pā ana ki tetahi kinetochores tīmatanga pou tāpiri ki microtubules i amo ritenga, kia e i roto i te tukanga metaphase ki kinetochores hono te i waenganui i tekau me wha tekau korere. huaina ana tēnei hanganga ko te kurupae kinetochore. Āta pā ana ia pūira kei ki te pou ritenga, a kua hanga e ratou i roto i te wahi pokapū o te pereti muka metaphase.

Ko te kōwhiringa tuarua

Tera atu ano tetahi tauira e i roto i nei kia hanga e te pou muka wehenga. Ko reira ano hoki taea mō ngā pūtau he te centrosome, a mo ngā pūtau i roto i nei, he mea motu ratou. Ko te tukanga, ka uru te mowhiti matatini kama tubulin, e tika ana ki nei i reira ko te nucleation poto o microtubules huri noa nga pūira. Korere piri ki te kinetochore-me-mutunga, i muri nei ka tīmata te polymerization o microtubules, e ko, tupu whakahaere. pito tōraro o te "Hanumi" ka noho i roto i te wehenga e tika ana ki te nekeneke pūmua amo. Ki te whai wāhi te hanganga o te muka te rua o centrosomes, whakahaere reira te hononga o microtubules, engari he taea te tukanga kahore ratou.

rite

He wehenga mārama i waenganui i nga pūira e rua o ngā pūtau i hanga i roto i wehenga, e taea anake tupu ki te nga chromatids takirua ratou kinetochores piri ki amo rerekē. huaina chromatids rerekētanga pourua te amfitepicheskogo, engari i reira e te tahi atu kōwhiringa e ara ake i te wa o te haere ki e rua pou muka wehenga. Tenei monotepicheskoe (kotahi kinetochores piri ki tetahi pou) me sintepicheskoe (e hono rua pūira kinetochore ki tetahi pou). A, no te mau merotepicheskom kinetochore kotahi e rua amo. He tikanga, here anake eu pourua e puta tika ana ki te tōpana renarena i te amo, he iu me te reversible te tahi atu tikanga honohono, engari kia waiho tika ki te wāhi o te kinetochore.