Nucleolar ayyuka a cikin cell abin? A nucleolus: sifa da aiki

Tantanin halitta shine asali naúrar na rayayyun kwayoyin halitta a duniya, kuma yana da hadadden kungiya Tsarin kira wasu gabbansa. Wadannan sun hada da tsakiya, tsarin da kuma ayyuka na wanda za mu bincika a wannan labarin.

Features na eukaryotic nuclei

Nucleated Kwayoyin a cikin abun da ke ciki ƙunshi maras membrane wasu gabbansa taso keya, thicker fiye da karyoplasm da kuma kira nucleolus ko nucleoli. Su aka gano a cikin karni na 19th. Yanzu nucleoli isasshe karatu ta hanyar electron bincike da madubin likita. Kusan har 50s na karni na 20th nucleolar aiki ba aka gano, da kuma masana kimiyya dauke da wannan organelle, wajen, a matsayin tafki na kayayyakin abubuwa amfani a lokacin mitosis.

Modern bincike ya tabbatar da cewa organoid hada granules nucleoprotein yanayi. Bugu da ƙari, biochemical gwaje-gwajen sun tabbatar cewa organelle qunshi wani babban yawan sunadaran. Wannan suka sa ta high yawa. Bugu da ƙari proteids, nucleoli ba a cikin abun da ke ciki a kananan adadin RNA da DNA.

cell sake zagayowar

Abin sha'awa, a cikin rãyuwar cell, wanda ya kunshi mai kyaun lokaci (Interphase) da rabo (meiosis - da jima'i, mitosis - da somatic cell), nucleoli adana m. Saboda haka, a cikin Interphase tsakiya tare da nucleolus, wanda aiki - adana daga cikin genome da kuma samuwar na furotin-rairaya da wasu gabbansa ne ba dole ba ne. A farkon cell division, wato prophase, suka bace da kuma sake kafa kawai a karshen telophase, ana sa a cikin wani keji har na gaba rabo ko don apoptosis - ta hallaka.

nucleolus Oganeza

A cikin 30s na karshe karni, masana kimiyya sun gano cewa, da samuwar nucleoli ne sarrafawa da wasu sassan na wasu chromosomes. Sun dauke da kwayoyin halittu, wanda adana bayani game da abin da tsarin da kuma abin da su ne ayyuka na nucleolus a cikin cell. Akwai hulda a tsakanin da yawa daga nucleolar Oganeza da wasu gabbansa da kansu. Alal misali, Afrika ta clawed rana ƙunshi a karyotype biyu nucleolus chromosome kuma haka a cikin nuclei na somatic Kwayoyin shi ne biyu nucleoli.

Tun da nucleolus ayyuka da kuma ta gaban da aka hankali hade da cell division da kuma samuwar ribosomes, da wasu gabbansa da kansu rasa a sosai na musamman kwakwalwa nama, da jini, da kuma a cikin zygote blastomeres Mace.

karawa da nucleoli

A roba mataki Interphase tare da DNA kwafi kai-maimaitawan auku wuce haddi na rRNA da kwayoyin halittu. Tun da babban aiki na nucleolus - samar da ribosomes, dangane da overexpression na loci DNA da cewa kawo bayanai game da RNA haifar da karuwar yawan wadannan da wasu gabbansa. Nucleoproteins, ba a hade tare da chromosomes fara aiki autonomously. A sakamakon - a jam'i nucleoli a tsakiya kafa, distancing kanta daga nucleolar chromosomes. Wannan sabon abu ne da ake kira karawa na rRNA da kwayoyin halittu. Ci gaba da karatu da aiki na nucleolus a cikin cell, mu lura da cewa mafi yawan aiki na kira na faruwa a meiotic prophase na meiosis, inda na farko domin oocytes iya ƙunsar da dama da ɗari nucleoli.

A nazarin halittu muhimmancin wannan sabon abu ya bayyana a lokacin da ka yi la'akari da cewa a farkon matakai na embryogenesis: crushing da blastulation, kana bukatar wata babbar adadin ribosomes rairaya da babban ginin abu - gina jiki. Karawa - fairly na kowa hanya, yana daukan wuri a cikin oogenesis na shuke-shuke, kwari, halittar dabba mai kafafuwa, yisti, da kuma wasu protists.

Histochemical abun da ke ciki da wasu gabbansa

Mun ci gaba da binciken na eukaryotic Kwayoyin da kuma wa gininsu, da kuma la'akari da nucleolus, tsarin da ayyuka wanda aka m. An gano cewa, shi ya ƙunshi iri uku abubuwa:

1. Nukleonemy (ke tsaye bakin ramin samuwar). Su iri-irin da kuma dauke da fibrils da lumps. Kamar yadda wani ɓangare na biyu shuka da kuma dabba Kwayoyin, nukleonemy form fibrillar cibiyoyin. Cytochemical sifa da aiki na nucleolus ne ma dogara a kan gaban a cikinta daga matrix - wani cibiyar sadarwa na reference gina jiki manyan tsarin da kwayoyin.
2. Vacuoles (highlights).
3. Granular katsin (nucleolin).

Daga cikin ra'ayinsa na sinadaran analysis, da organoid kunshi kusan gaba ɗaya na RNA da DNA da furotin da kuma ne kawai a ta periphery, kafa wani tsarin annular - okoloyadryshkovy chromatin.

Saboda haka mun tabbatar da cewa tsarin da nucleolus aka hada da biyar abokai: da granular da fibrillar cibiyoyin, chromatin, da furotin da kuma reticulum m fibrillar bangaren.

iri nucleoli

Biochemical tsarin wadannan da wasu gabbansa dogara a kan salula irin a cikin abin da suka kasance ba, kazalika da halaye na su metabolism. Rarrabe 5-daban na asali tsarin nucleoli. Origin - reticular, ya fi na kowa, kuma shi ne halin da wani yawa na m fibrillar abu clumps da nucleoproteins nucleons. Kan aiwatar da rewriting bayanai nucleolar Oganeza ne sosai aiki, don haka da fibrillar cibiyoyin ne talauci a bayyane karkashin hange.

Tun da babban aiki na nucleolus a cikin cell - kira na ribosomal subunits, na wanda ya samar da furotin-rairaya da wasu gabbansa, da reticular irin kungiyar muhimmi a duka biyu shuka da dabbobi Kwayoyin. Nucleoli annular irin ta auku a cikin connective nama Kwayoyin: lymphocytes da kuma endothelial Kwayoyin, wanda kwayoyin halittu suna a rubuce rRNA kusan. Saura nucleoli da ake samu a Kwayoyin gaba daya rasa ikon kwafi, misali, normoblasts da enterocytes.

Nuna wa mata banbanci irin muhimmi Kwayoyin sun samu maye Carcinogens, maganin rigakafi. A karshe, wani m irin nucleolar fibrillar cibiyoyin halin da wani sa da kuma wani karamin yawan nucleons.

Nucleolar gina jiki matrix

Mun ci gaba da binciken na ciki tsarin da kwaya Tsarin da kuma sanin abin da suke da ayyuka na nucleolus a cell metabolism. An sani cewa game da 60% da bushe nauyi da dama a kan wannan organelle sunadaran da cewa yin up chromatin, ribosomal gaɓũɓuwa, kazalika da ta dace nucleolar sunadaran. Bari mu bincika su daki-daki. Sashe na daga cikin proteids ne da hannu a cikin aiki - da samuwar balagagge ribosomal RNA. Wadannan sun hada da RNA polymerase 1 da kuma nuclease cewa cire wuce haddi triplets da duk rRNA kwayoyin. Protein fibrillarin located in m fibrillar bangaren kuma, kamar nuclease, kuma ya aikata aiki. Wani gina jiki - nucleolin. Tare da fibrillarin shi ne a cikin PFC da kuma FC nucleoli da nucleolar Oganeza chromosome prophase na mitosis.

Irin wannan polypeptide kamar yadda nukleofozin located in granular zone da wani m fibrillar bangaren, shi ke taka rawa a cikin samuwar ribosomal 40 S da kuma 60 S subunits.

Menene nucleolus

Kira na ribosomal RNA - babban aiki na wanda shi ne ya yi nucleoli. A wannan lokaci, a kan bãyan tẽkun (Ina nufin a fibrillar cibiyoyin) ya auku kwafi da enzyme RNA polymerase. A wannan nucleolar Oganeza hada daruruwan pre-ribosomes ribonucleoprotein kira globules. Daga waɗanda kafa ribosomal subunits cewa ta hanyar makamashin nukiliya pores da kuma barin karyoplasm kansu a cikin cell cytoplasm. The kananan subunit 40s aka haɗa zuwa ga manzo RNA, kuma kawai bayan da cewa manyan subunit 40s ne a haɗe zuwa gare su. Image na balagagge ribosome iya zuwa watsa shirye-shirye - kira na salula sunadaran.

A wannan labarin, za mu nucleolar sifa da aiki da aka yi karatu a shuka da dabbobi Kwayoyin.