Nucleolar zog nyob rau hauv lub cell dab tsi? Lub nucleolus: qauv thiab muaj nuj nqi

Lub cell yog lub hauv paus uas muaj sia nyob rau lub ntiaj teb, thiab muaj ib tug complex tshuaj lub koom haum lug hu ua organelles. Cov muaj xws li cov nucleus, cov qauv thiab cov kev khiav dej num ntawm cov uas peb yuav tshawb nyob rau hauv no tsab xov xwm.

Nta ntawm eukaryotic nuclei

Nucleated hlwb nyob rau hauv nws muaj pes tsawg leeg muaj uas tsis yog-daim nyias nyias organelles npawv, thicker tshaj karyoplasm thiab hu ua nucleolus los yog nucleoli. Lawv nyob sab nyob rau hauv lub xyoo pua puv 19. Tam sim no nucleoli sufficiently kawm los ntawm electron microscopy. Yuav luag kom txog thaum lub 50s ntawm lub xyoo pua 20th nucleolar muaj nuj nqi tsis tau tias, thiab zaum xam tau tias yog no organelle, es, raws li ib tug reservoir ntawm spare tshuaj siv thaum lub sij hawm mitosis.

Niaj hnub nimno cov kev tshawb fawb tau tsim hais tias tus organoid muaj xws li granules nucleoprotein xwm. Ntxiv mus, biochemical thwmsim paub tseeb tias cov organelle muaj ib tug loj tus naj npawb ntawm proteins. Hais tias lawv ua rau nws cov high ceev. Tsis tas li ntawd proteids, nucleoli tam sim no nyob rau hauv muaj pes tsawg leeg ib tug me me npaum li cas ntawm RNA thiab DNA.

cell voj voog

Interestingly, nyob rau hauv lub neej ntawm lub cell, uas muaj ib tug so lub sij hawm (interphase) thiab sib faib (meiosis - tus txiv neej pw, mitosis - lub Somatic cell), nucleoli muab qhov. Yog li ntawd, nyob rau hauv lub interphase nucleus nrog lub nucleolus, uas ua - preservation ntawm lub genome thiab tsim los ntawm cov protein-synthesizing organelles yog tam sim no tas. Thaum pib ntawm cell division, namely prophase, lawv ploj thiab re-tsim tsuas yog nyob rau hauv lub kawg ntawm telophase, raug khaws cia nyob rau hauv ib lub tawb kom txog thaum tom ntej no division los yog mus rau kev puas ntsoog - nws puas tsuaj.

nucleolus organizer

Nyob rau hauv lub 30s ntawm lub xeem caug xyoo, zaum tau pom hais tias tus tsim ntawm nucleoli yog tswj los ntawm tej yam seem ntawm tej yam chromosomes. Lawv muaj noob, uas cia cov lus qhia hais txog dab tsi qauv thiab dab tsi yog lub zog ntawm lub nucleolus nyob rau hauv lub cell. Muaj yog ib tug correlation ntawm cov nuj nqis ntawm nucleolar organizer thiab organelles lawv tus kheej. Piv txwv li, lub African clawed Qav muaj nyob rau hauv nws cov karyotype ob nucleolus chromosome thiab li nyob rau hauv lub nuclei ntawm Somatic hlwb nws yog ob nucleoli.

Txij li thaum lub nucleolus zog raws li zoo raws li nws muaj yog zoo txuam nrog cell division thiab tsim los ntawm ribosomes, lub organelles lawv tus kheej tsis nyob rau hauv heev tshwj xeeb hlwb cov ntaub so ntswg, cov ntshav, thiab nyob rau hauv lub zygote blastomeres Mace.

amplification ntawm nucleoli

Cov khoom cua kauj ruam interphase nrog DNA replication self-doubling tshwm sim ntau heev ntawm rRNA noob. Txij li thaum lub ntsiab muaj nuj nqi ntawm lub nucleolus - zus tau tej cov ribosomes, nyob rau hauv kev twb kev txuas nrog cov overexpression ntawm loci DNA uas nqa cov lus qhia txog cov RNA dramatically nce tus naj npawb ntawm cov organelles. Nucleoproteins, tsis txuam nrog lub chromosomes pib ua autonomously. Raws li ib tug tshwm sim - ib tug plurality nucleoli nyob rau hauv keeb tsim, distancing nws tus kheej los ntawm cov nucleolar chromosomes. Qhov no tshwm sim yog hu ua amplification ntawm rRNA noob. Ntxiv mus kawm cov kev ua ntawm lub nucleolus nyob rau hauv lub cell, peb nco ntsoov tias lub feem ntau active ntawm synthesis tshwm sim nyob rau hauv meiotic prophase ntawm meiosis, uas thawj thiaj li oocytes tej zaum yuav muaj ob peb puas nucleoli.

Lub lom tseem ceeb ntawm no phenomenon yuav meej thaum koj xav txog hais tias nyob rau hauv thaum ntxov ua sawv ntawm embryogenesis: crushing thiab blastulation, koj xav tau ib tug lossis loj npaum li ntawm ribosomes synthesizing lub tsev cov ntaub ntawv uas - protein. Amplification - haum ntau txoj kev, nws yuav siv sij hawm qhov chaw nyob rau hauv lub oogenesis ntawm cov nroj tsuag, kab, amphibians, poov xab, thiab ib co protists.

Histochemical muaj pes tsawg leeg organelles

Peb mus txuas ntxiv rau txoj kev tshawb ntawm eukaryotic hlwb thiab lawv lug, thiab xav txog tej nucleolus, qauv thiab kev khiav dej num uas yog ke. Nws yog pom hais tias nws muaj peb hom hais:

1. Nukleonemy (whiskers tsim). Lawv yog cov ua kev thiab muaj fibrils thiab lumps. Raws li ib feem ntawm ob nroj tsuag thiab tsiaj hlwb, nukleonemy daim ntawv fibrillar chaw zov me nyuam. Cytochemical qauv thiab muaj nuj nqi ntawm lub nucleolus yog tseem nyob rau hauv lub xub ntiag nyob rau ntawd ntawm lub matrix - ib tug network ntawm reference protein tertiary qauv ntawm cov molecules.
2. Vacuoles (highlights).
3. Granular pellets (nucleolin).

Los ntawm qhov seem yus pom ntawm tshuaj tsom xam, cov organoid muaj yuav luag nkaus ntawm RNA thiab protein thiab DNA yog tsuas yog nyob rau nws cov periphery, sib sau ib annular qauv - okoloyadryshkovy chromatin.

Yog li ntawd peb tau tsim muaj uas cov qauv ntawm cov nucleolus yog muaj li ntawm tsib cov chaw: lub granular thiab fibrillar chaw zov me nyuam, chromatin, lub protein reticulum thiab tuab fibrillar tivthaiv.

hom nucleoli

Biochemical qauv ntawm cov organelles nyob rau hauv lub cell hom nyob rau hauv uas lawv yog tam sim no, raws li zoo raws li tus yam ntxwv ntawm lawv metabolism. Paub qhov txawv 5 hom yooj yim ntxwv nucleoli. Keeb kwm - reticular, feem ntau thiab yog yus muaj los ntawm ib tug nplua mais ntawm tuab fibrillar khoom koog puav thiab nucleoproteins nucleons. Tus txheej txheem ntawm rewriting ntaub ntawv nucleolar organizer yog heev kom nquag plias, yog li lub fibrillar chaw zov me nyuam yog tsis zoo pom nyob rau hauv lub tshuab kuaj kab mob.

Txij li thaum lub ntsiab muaj nuj nqi ntawm lub nucleolus nyob rau hauv lub cell - lub synthesis ntawm ribosomal subunits, ntawm uas tsim lub protein-synthesizing organelles, lub reticular hom ntawm lub koom haum xam qhovkev nyob rau hauv ob qho tib si nroj tsuag thiab tsiaj hlwb. Nucleoli annular hom tshwm sim nyob rau hauv cov ntaub so ntswg connective hlwb: lymphocytes thiab endothelial hlwb, uas nws cov noob yog transcribed rRNA suab. Qhov seem nucleoli yog pom nyob rau hauv lub hlwb ua poob lawm lub peev xwm los transcription, piv txwv li, normoblasts thiab enterocytes.

Segregated zoo ntawm xam qhovkev hlwb muaj tej intoxication carcinogens, tshuaj tua kab mob. Thaum kawg, ib tug compact hom nucleolar fibrillar chaw zov me nyuam yus muaj los ntawm ib tug txheej thiab ib tug me me muaj pes tsawg tus ntawm nucleons.

Nucleolar protein matrix

Peb mus txuas ntxiv rau txoj kev tshawb ntawm lub internal qauv ntawm cov ntsiav lug thiab txiav txim seb dab tsi yog qhov kev khiav dej num ntawm lub nucleolus nyob rau hauv cell metabolism. Nws yog lub npe hu hais tias hais txog 60% los ntawm qhuav nyhav ntog rau qhov no organelle proteins uas ua li chromatin, ribosomal hais, raws li tau zoo raws li kom nucleolar proteins. Cia peb kawm lawv nyob rau hauv kom meej. Ib feem ntawm cov proteids yog muab kev koom tes nyob rau hauv lub ua - qhov tsim ntawm mature ribosomal RNA. Cov no muaj xws RNA polymerase 1 thiab nuclease uas tshem tawm cov triplets nrog tag nrho cov rRNA molecules. Protein fibrillarin nyob rau hauv tuab fibrillar tivthaiv thiab, zoo li nuclease thiab ua ua. Lwm protein - nucleolin. Ua ke nrog fibrillarin nws yog nyob rau hauv lub PFC thiab FC nucleoli thiab nucleolar organizer chromosome prophase ntawm mitosis.

Tej polypeptide li nukleofozin nyob rau hauv granular cheeb tsam thiab ib tug tuab fibrillar tivthaiv, nws koom nyob rau hauv lub tsim ntawm ribosomal 40 S thiab 60 S subunits.

Li cas rau cov nucleolus

Lub synthesis ntawm ribosomal RNA - lub ntsiab hauj lwm ntawm uas yog ua nucleoli. Thaum lub sij hawm no, nyob rau nws saum npoo (i.e. nyob rau hauv fibrillar chaw zov me nyuam) tshwm sim transcription los ntawm cov enzyme RNA polymerase. Thaum no nucleolar organizer tsim pua pua ntawm pre-ribosomes ribonucleoprotein hu ua globules. Ntawm cov neeg tsim ribosomal subunits hais tias los ntawm lub nuclear pores thiab tawm karyoplasm lawv tus kheej nyob rau hauv lub cell cytoplasm. Lub me me subunit 40s yog kev cob cog rua rau tus tub txib RNA, thiab tsuas yog tom qab uas lub loj subunit 40s yog txuas mus rau lawv. Duab ntawm ib tug paub tab ribosome muaj cuab kav mus tshaj tawm hauv xov - lub synthesis ntawm cellular proteins.

Nyob rau hauv no tsab xov xwm peb nucleolar qauv thiab muaj nuj nqi yog kawm nyob rau hauv nroj tsuag thiab tsiaj hlwb.