Chokurukisa - zviri ... Description, mamiriro uye mashandiro

Chokurukisa nokupesana - kwekanguva maumbirwo yakaumbwa mumakore nedanho mitosis uye meiosis, uye kupa mashoko okutodza panguva iyoyo uye masero kupesana. It nedambudziko: microtubule hurongwa achiumbwa nzvimbo pakati namatanda, chimiro chokurukisa. The centromere kumiganhu chromosome kinetochores vari vasiyana chokurukisa microtubules. Maererano kwaari okutodza kufamba akananga matanda.

mamiriro

Chokurukisa ine zvitatu zvinokosha STRUCTURAL zvinhu: microtubules, okutodza uye weboka nematanda. Danda kupatsanura mhuka dzinorongwa nomukombiyuta centrosome, ane centrioles. Kana nzvimbo pasina centrosomes (mu zvirimwa, uye mune oocytes dzimwe mhuka) chokurukisa rine upamhi pabango uye inonzi atsentrosomalnym. In paumbwe chokurukisa zvinobatanidzwa ndeimwe chivako - motokari mapurotini. Vanopinda dynein uye kinesin.

Chokurukisa nokupesana - munhu nechirwere marongerwo. Matanda Vose dziri centrosomes - organelles kuti ndiyo nzvimbo microtubule sangano. The nemamiriro centrosome kusiyanisa centrioles maviri, ayo takapoteredzwa zhinji mapurotini siyana. Yaiitwa yakapfupikiswa okutodza vane chimiro chromatids zviviri zvakabatanidzwa panguva centromere site iri pakati matanda. Munguva centromeres vari kinetochores, inoitika kubatana kwakaita microtubules.

inotungamirwa

Sezvo weboka chokurukisa - marongerwo kuti ndiye anokonzera muchitokisi nokupesana, kutanga ungano yacho unowanikwa prophase. In miti uye mune oocytes pasina centrosomes, microtubule pakuronga centre anoshumira goko ari musimboti. Microtubules vari pedyo hamvuropu renyukireya uye inoguma mukupera prophase zvadziri, uye vanoumba "prophase chokurukisa" - ramangwana chokurukisa akabatana.

Nokuti kuti masero mhuka ari centrosome kuridza basa sangano pakati, mavambo paumbwe mitotic chokurukisa ndiyo zvakatosiyana pakati centrosomes maviri panguva prophase. Izvi zvinogoneka nokuti injini mapuroteni dynein vari vasiyana rokunze pose chinoumba uye yomukati kurutivi muchitokisi membrane. boka dynein vasiyana Kamudzira, kwakabatana astral microtubules uye vanotanga kutamira kune akaipa mugumo, nokuda paine dilution pakati centrosomes panguva pakatarisana nzvimbo muchitokisi membrane.

Mugumo ungano

Kwokupedzisira nezvekugadzirwa chokurukisa ndepana prometaphase danho, pashure kunyangarika ari Kamudzira inova zvakakwana chinoumba, nokuti ipapo centrosomes uye microtubules vanogona kuwana zvakamisa hurongwa chokurukisa.
Zvisinei, pane chimwe Kusara: asi yotunga mbiriso mitotic chokurukisa inotungamirwa kunoitika mukati musimboti.

neshinda chokurukisa inotungamirwa uye zvadziri hazvibviri pasina pezvakaitwa maviri: sangano microtubules akapoteredza okutodza uye kubatana kwavo kune mumwe nomumwe ari pakatarisana matanda weboka. Vakawanda kudiwa chokupedzisira paumbwe chokurukisa, kusanganisira okutodza uye injini mapuroteni vakawana mukati muchitokisi musimboti, uye microtubules uye, kana mhuka sero centrosomes zviri cytoplasm, i.e., zvakamisa hurongwa vari kure nomumwe. Ndokusaka paumbwe chokurukisa inoguma chete pashure kunyangarika hamvuropu renyukireya.

va- okutodza

Pakugadzirwa mitotic chokurukisa mapuroteni rinobatanidzwa, uyewo nedzimwe nhengo zhinji, uye izvi zvave zvakanaka kudzidza mumasero mhuka. Panguva prophase, microtubules vanoumba akapoteredza centrosome stellate mamiriro iyo diverges mu TOUR divi. Mushure renyukireya Kamudzira musisiri, vakagwinya kusagadzikana pamusoro microtubules dzinotanga vanoshingaira kuongorora nzvimbo iyi uye kinetochores okutodza zvinogona wakaiswa kwavari. Vamwe chikamu chromosome pakarepo akatsauka pana akatarisana mapango, uye vanosara -bhainda rokutanga microtubules mumwe matanda, uye chete ipapo kutanga kufamba akananga rworudyi danda. Kana muitiro kwapera, okutodza, kare chokuita chero danda kutanga kinetochores kuisa microtubules kubva pakatarisana matanda, saka kuti panguva metaphase kwacho kune kinetochores kwakabatana pakati sepombi gumi uye mana. inotungamirwa iyi inonzi kinetochore danda. Zvishoma nezvishoma mumwe chromosome Rinobatanidzwa nevakomana padanda, uye vari akaumba nechepakati chikamu chokurukisa metaphase ndiro.

The pfungwa yechipiri

Pane imwe chiitiko umo chokurukisa ingangoumbwa nokupesana. Zvinogonekawo kuti masero ane centrosome, uye nokuda masero dzavakasiyana vasipo. Kwacho kunosanganisira wegamma tubulin mhete yakaoma, nokuda iyo pane pfupi nucleation pamusoro microtubules akapoteredza okutodza. Sepombi vasiyana kinetochore-ndinoiitawo-mugumo, pashure izvo polymerization pamusoro microtubules kunotanga, kureva, dzinodzorwa kukura. Negative kumigumo "Kubatanidza" uye kuramba weboka nokuda injini mapurotini nematanda. Kana paumbwe chokurukisa nechokuita peya centrosomes, izvozvo hwezvekukurukurirana kubatana kwakaita microtubules, asi zvichiitika zvinogoneka pasina pavo.

zvakafanana

A zvakajeka zviparadzanise okutodza maviri masero yakawanikwa panguva fission, zvinogona kuitika chete kana aiwanzopiwa wokushanda chromatids kinetochores dzavo anonamatirana nematanda siyana. Nechirwere musiyano chromatids anonzi amfitepicheskogo, asi pane dzimwe nzira kuti inomuka panguva yokuenda vose nokupesana chokurukisa. monotepicheskoe ichi (imwe kinetochores kurerekera rimwe danda) uye sintepicheskoe (zvose kinetochore okutodza chokuita chimwe danda). Apo mumwe kinetochore merotepicheskom ari anoteyiwa nematanda maviri. Akatsiga chete kwakajairika, nechirwere chisungo kuti kunoitika nokuda makakatanwa nechisimba namatanda, mumwe chokuedza nzira dzinotsauka uye reversible, asi anogona kuva nokuda nzvimbo kinetochore.