Qhov sib txawv tseem ceeb ntawm heterochromatin thiab euchromatin yog heterochromatin yog cov ntawv ntim ntau ntawm chromatin uas feem ntau tsis ua haujlwm thaum euchromatin yog daim ntawv xoob xoob ntawm chromatin uas feem ntau ua haujlwm.
Chromatin yog cov qauv uas tuav cov DNA strand ntawm chromosome. Heterochromatin thiab euchromatin yog ob hom chromatin uas muaj nyob hauv cov hlwb. Muaj qhov sib txawv ntawm heterochromatin thiab euchromatin raws li cov qauv thiab kev ua haujlwm. Tsis tas li ntawd, lawv txawv ntawm cov ntawv sau thiab cov khoom siv rov ua dua ib yam nkaus.
Heterochromatin yog dab tsi?
Heterochromatin yog daim ntawv nruj ntawm chromatin tam sim no hauv cov hlwb ntawm eukaryotes. Nws feem ntau muaj nyob rau ntawm qhov nruab nrab ntawm lub nucleus. Vim nws qhov xwm txheej heev, nws pom tau thaum lub sij hawm staining ntawm DNA ntawm ib lub xov tooj ntawm tes. Tsis tas li ntawd, qhov no stained DNA muaj ob hom; Lawv yog cov tsim thiab facultative heterochromatin. Kev tsim kho heterochromatin yog lub luag haujlwm tseem ceeb rau kev tsim cov centromere lossis telomere thaum nyiam cov cim qhia rau cov noob caj noob ces thiab kev tsim txom. Facultative heterochromatin yuav rov ua dua nyob rau hauv cov cim tshwj xeeb lossis ib puag ncig; txwv tsis pub, nws nyob twj ywm nrog ib tug heev condensed qauv. Lub luag haujlwm tseem ceeb ntawm heterochromatin yog los tiv thaiv DNA strand. Tsis tas li ntawd, chromatin pab hauv kev tswj cov noob. Thaum muaj DNA strand yam tsis muaj heterochromatin, muaj peev xwm ntawm endonucleases tsis tsim nyog zom cov khoom ntawd.
Daim duab 01: Heterochromatin
Txoj kev cuab yeej cuab tam kom ntseeg tau tias muaj heterochromatin nyob rau tiam tom ntej. Feem ntau, cov qauv condensed ntawm heterochromatin tiv thaiv cov noob caj noob ces tsis xav kom txog thaum lub teeb liab tshwj xeeb tuaj txog thiab qhia rau cov DNA tsis pom zoo kom nthuav tawm DNA strands rau kev hloov pauv. Feem ntau, kev rov ua dua ntawm DNA hauv heterochromatin tshwm sim nyob rau theem tom ntej. Nws cov qauv compact txiav txim siab feem ntau ntawm cov dej num hauv cov noob qhia; qhov tseeb, nws yog qee zaum hu ua gene silencing.
YEuchromatin yog dab tsi?
Euchromatin yog cov txheej txheem DNA nyob hauv cov hlwb uas xoob xoob. Feem ntau, lawv muaj nyob rau hauv lub hauv paus ntawm lub nucleus. Euchromatin muaj nyob rau hauv ob qho tib si prokaryotes thiab eukaryotes. Qhov tseeb, euchromatin yog tib hom chromatin tam sim no hauv cov khoom siv caj ces prokaryotic. Ntxiv mus, nws cov qauv ntim xoob ua rau tsis pom kev thaum lub sijhawm DNA staining, tsis zoo li heterochromatin.
Daim duab 02: Euchromatin
Qhov tsis muaj qhov tsis txaus ntseeg ntawm euchromatin feem ntau yog vim qhov xoob qhwv ntawm histone proteins nyob ib puag ncig DNA strand. Yog li ntawd, kev nkag mus ntawm DNA yog ib qho yooj yim los pib DNA transcription. Ntxiv mus, euchromatin muaj cov noob caj noob ces feem ntau ntawm lub cev. Nws yog vim tias euchromatin koom nrog hauv kev hloov pauv ntawm DNA rau hauv mRNA. Qee cov euchromatins tsis yog ib txwm hloov pauv tab sis hloov mus rau hauv heterochromatin tom qab qhov kev ua haujlwm yooj yim kom ntsiag to cov noob. Txawm li cas los xij, muaj qee qhov ua haujlwm euchromatins los tswj kev ruaj ntseg ntawm cov txheej txheem tseem ceeb thiab tseem ceeb rau kev ciaj sia ntawm cov cell.
Dab tsi zoo sib xws ntawm Heterochromatin thiab Euchromatin?
- Heterochromatin thiab euchromatin yog ob hom chromatin tam sim no hauv cov hlwb eukaryotic.
- Ob hom chromatin muaj nyob hauv lub nucleus.
- Ntxiv mus, lawv yog cov complexes ntawm DNA thiab cov proteins.
- Thiab, ob leeg koom nrog DNA transcription.
- Tsis tas li, lawv ob leeg cuam tshuam nrog histone proteins.
Qhov txawv ntawm Heterochromatin thiab Euchromatin yog dab tsi?
Heterochromatin thiab euchromatin yog ob hom chromatin tam sim no hauv cov kab mob muaj sia. Qhov sib txawv tseem ceeb ntawm heterochromatin thiab euchromatin yog qhov heterochromatin yog cov ntawv ntim ntau ntawm chromatin hauv lub nucleus thaum euchromatin yog cov ntaub ntawv xoob xoob ntawm chromatin hauv lub nucleus. Feem ntau, heterochromatin tsis ua haujlwm thaum euchromatin ua haujlwm. Yog li ntawd, heterochromatin muaj ntau DNA, thaum euchromatin muaj tsawg DNA. Yog li, qhov no yog lwm qhov sib txawv ntawm heterochromatin thiab euchromatin.
Tsis tas li ntawd, qhov sib txawv tseem ceeb ntawm heterochromatin thiab euchromatin yog tias heterochromatin tsawg dua. Tab sis, nyob ib ncig ntawm 90% ntawm tag nrho cov tib neeg genome yog euchromatin. Tsis tas li ntawd, qhov sib txawv ntxiv ntawm heterochromatin thiab euchromatin yog tias heterochromatin tsuas muaj nyob hauv eukaryotes, tab sis, euchromatin muaj nyob rau hauv ob qho tib si prokaryotes thiab eukaryotes.
Summary – Heterochromatin vs Euchromatin
Heterochromatin thiab euchromatin yog ob hom chromatin. Qhov sib txawv tseem ceeb ntawm heterochromatin thiab euchromatin yog lub ntim. Heterochromatin yog cov ntawv ntim ntau heev ntawm chromatin thaum euchromatin yog daim ntawv xoob xoob ntawm chromatin. Yog li, heterochromatin muaj ntau DNA thaum euchromatin muaj DNA tsawg. Tab sis, heterochromatin feem ntau tsis ua haujlwm thaum euchromatin feem ntau ua haujlwm. Yog li, qhov no yog cov ntsiab lus ntawm qhov sib txawv ntawm heterochromatin thiab euchromatin.
