Qhov sib txawv tseem ceeb ntawm kev hloov pauv rov qab thiab kev hloov pauv hloov pauv yog qhov rov qab hloov pauv hloov pauv hloov pauv hloov pauv mus rau qhov qub, hom tsiaj qus thaum cov kev hloov pauv hloov ua rau cov kev hloov pauv tseem ceeb los ntawm kev tsim cov khoom lag luam protein inhibited los ntawm kev hloov pauv thawj zaug.
Kev hloov pauv yog kev hloov pauv ntawm nucleotide ib ntus ntawm DNA molecule hauv genome ntawm ib yam kabmob. Li no, kev hloov pauv tshwm sim vim qhov ua yuam kev tshwm sim thaum lub sij hawm mitosis thiab meiosis thiab kuj yog vim muaj ntau yam xws li hluav taws xob, tshuaj lom neeg, thiab lwm yam. Hom kev hloov pauv feem ntau yog kev hloov mus rau pem hauv ntej. Nws yog hom kev hloov pauv tseem ceeb. Forward mutation hloov cov tsiaj qus-hom ib txwm genotype mus rau mutant genotype. Raws li, nyob ntawm seb hom kev hloov pauv, nws cov nyhuv txawv. Txawm li cas los xij, qee qhov kev hloov pauv tuaj yeem kho qhov cuam tshuam ntawm kev hloov pauv thawj zaug. Back mutation thiab suppressor mutation yog ob hom kev hloov pauv. Lawv koom nrog kev thim rov qab qhov cuam tshuam ntawm kev hloov pauv thawj zaug.
Kev hloov pauv rov qab yog dab tsi?
Kev hloov pauv rov qab lossis rov qab hloov pauv yog qhov xwm txheej uas cov genotype hloov pauv mus rau hom qub qub. Yog li ntawd, tus txheej txheem no tag nrho rov qab mus rau pem hauv ntej hloov pauv. Hom kev hloov pauv no tuaj yeem pom meej meej hauv cov kab mob auxotrophic uas lawv rov qab mus rau phototrophs. Qhov no yog qhov tseeb heev thaum cov hlwb ntawm thawj auxotrophic hom yog plated hauv cov xov xwm tsawg thiab pom. Qhov peev xwm ntawm cov noob hloov pauv hloov mus rau qhov qub yam tsiaj qus, qhia qhov tseeb tias, qee qhov kev hloov pauv, nws tsis yog txheej txheem tas mus li, tab sis thim rov qab.
Tsis tas li ntawd, kev hloov pauv rov qab tshwm sim hauv txoj hauv kev sib txawv. Nyob rau hauv qhov tseeb rov qab mutation, restoration ntawm thawj lub hauv paus khub ib ntus yuav siv qhov chaw. Yog li ntawd, yog tias ib khub GC ntawm thawj hom tsiaj qus genome yog hloov los ntawm ib khub AT nyob rau hauv tus txheej txheem ntawm kev hloov mus rau pem hauv ntej, qhov tseeb rov qab hloov pauv tuaj yeem hloov GC khub ntawm tib txoj haujlwm.
Daim duab 01: Kev hloov pauv
Txawm li cas los xij, hauv qee qhov kev hloov pauv mus tom ntej, tus khub sib txawv tau muab tso rau ntawm qhov chaw ntawm tus khub hloov pauv. Yog tias thaum AT hloov GC, qhov kev hloov pauv rov qab tuaj yeem tshwm sim nrog kev hloov ntawm CG es tsis yog GC. Qhov tshwm sim zoo li no yuav ua rau muaj qhov rov qab phenotype txawm hais tias qhov sib lawv liag txawv ntawm qhov qub-hom kab sib lawv liag nyob rau hauv ib lub hauv paus khub.
Kev Hloov Pauv Hloov Pauv yog dab tsi?
Ib qho kev hloov pauv hloov pauv yog hom kev hloov pauv thib ob uas nws rov ua haujlwm poob los ntawm kev hloov pauv thawj zaug. Suppressor mutations yog ob hom; lawv yog intragenic suppressor mutation thiab intergenic suppressor mutation. Ntxiv mus, suppressor mutations tshwm sim nyob rau hauv ntau txoj kev. Intragenic suppressor mutation (kev hloov pauv thib ob) tshwm sim hauv cov noob uas yog thawj qhov kev hloov pauv tab sis nyob rau hauv ib qho chaw sib txawv. Ntawm qhov tod tes, intergenic suppressor kev hloov pauv tshwm sim hauv cov noob sib txawv uas tsis muaj qhov hloov pauv thawj zaug.
Txawm li cas los xij, thaum ob qho tib si intragenic thiab intergenic suppressor mutations, ib qho tshwm sim tshwm sim. Ntawd yog, ob hom kev hloov pauv thib ob (intragenic thiab intergenic) ua ke cov khoom ua haujlwm ntawm cov noob uas cuam tshuam los ntawm thawj qhov kev hloov pauv. Piv txwv li, yog tias thawj qhov kev hloov pauv hauv cov noob X inhibits kev tsim cov protein X, qhov kev hloov pauv uas tshwm sim hauv tib lub noob lossis cov noob sib txawv yuav ua rau tsim cov protein X. Raws li qhov tshwm sim, cov txheej txheem no thim rov qab cov txiaj ntsig ntawm cov noob X hloov pauv hauv qhov tsis ncaj.
Dab tsi yog qhov zoo sib xws ntawm Back Mutation thiab Suppressor Mutation?
- Kev hloov pauv rov qab thiab kev hloov pauv hloov pauv yog hom kev hloov pauv thib ob.
- Ob leeg cuam tshuam rau thawj qhov kev hloov pauv ncaj qha.
- Tsis tas li, ob qho tib si ua haujlwm kom thim rov qab cov txiaj ntsig ntawm kev hloov pauv thawj zaug.
Dab tsi yog qhov txawv ntawm Kev Hloov Rov Qab thiab Kev Tiv Thaiv Kev Hloov Pauv?
Kev hloov pauv rov qab thiab kev hloov pauv hloov pauv yog ob hom kev hloov pauv uas thim rov qab cov txiaj ntsig ntawm kev hloov pauv thawj zaug. Back mutation hloov cov mutant phenotype rov qab rau hauv cov tsiaj qus-hom phenotype. Suppressor mutation kho cov txiaj ntsig ntawm kev hloov pauv thawj zaug los ntawm kev tsim cov khoom ntawm cov noob hloov pauv. Yog li, qhov no yog qhov sib txawv tseem ceeb ntawm kev hloov pauv rov qab thiab kev hloov pauv hloov pauv.
Tsis tas li ntawd, kev hloov pauv rov qab kho cov noob hloov pauv thaum cov kev hloov pauv hloov tsis kho cov noob. Hloov chaw, nws tsim cov khoom lag luam protein uas tau thaiv vim qhov kev hloov pauv thawj zaug. Yog li, qhov no yog lwm qhov sib txawv ntawm kev hloov pauv rov qab thiab kev hloov pauv hloov.
Cov hauv qab no nthuav tawm cov ntsiab lus ntxiv ntawm qhov sib txawv ntawm kev hloov pauv rov qab thiab kev hloov pauv hloov pauv.
Summary – Back Mutation vs Suppressor Mutation
Forward mutations hloov cov tsiaj qus-hom ib txwm genotype rau hauv hom mutant. Ob qho kev hloov pauv rov qab thiab kev hloov pauv hloov pauv rov qab los ntawm kev hloov pauv thawj zaug ncaj qha lossis tsis ncaj. Back mutation los yog thim rov qab mutation yog ib yam mob uas cov mutant genotype hloov mus rau thawj hom qus. Ntawm qhov tod tes, suppressor mutation yog ib hom kev hloov pauv thib ob uas tuaj yeem rov ua haujlwm poob los ntawm kev hloov pauv thawj zaug. Hauv kev hloov pauv hloov pauv, thawj qhov kev hloov pauv tau tshwm sim tab sis cuam tshuam ncaj qha rau nws, qhov uas nws npog cov teebmeem phenotypic ntawm thawj qhov kev hloov pauv. Li no, qhov no yog qhov sib txawv ntawm kev hloov pauv rov qab thiab kev hloov pauv hloov.
