Qhov sib txawv tseem ceeb ntawm kev hloov mus rau pem hauv ntej thiab thim rov qab yog qhov hloov pauv mus tom ntej yog qhov hloov pauv uas hloov cov phenotype los ntawm hom tsiaj qus mus rau mutant thaum rov qab hloov pauv yog qhov hloov pauv uas hloov cov phenotype ntawm mutant mus rau hom tsiaj qus.
Kev hloov pauv yog kev hloov pauv ntawm nucleotide ib ntu ntawm cov noob lossis cov genome. Kev hloov pauv tuaj yeem tshwm sim hauv cov hlwb somatic lossis cov cell germline. Germline mutations dhau los ntawm niam txiv mus rau cov xeeb ntxwv, thaum somatic kev hloov pauv tsis dhau mus rau tiam tom ntej. Ntxiv mus, yog tias peb xav txog ib qho chaw nrog ob qho alleles, kev hloov pauv tuaj yeem ua rau pem hauv ntej lossis thim rov qab. Kev hloov mus rau pem hauv ntej yog kev hloov pauv uas hloov cov tsiaj qus allele mus rau qhov tsis zoo allele. Hauv qhov sib piv, thim rov qab kev hloov pauv hloov pauv qhov uas twb hloov pauv lawm (mutant) mus rau hom tsiaj qus allele, thim rov qab kev hloov pauv mus tom ntej.
Forward Mutation yog dab tsi?
Kev hloov pauv mus tom ntej yog kev hloov pauv uas hloov cov tsiaj qus allele rau hauv kev puas tsuaj allele. Cov phenotype uas pom nyob rau hauv cov pejxeem feem ntau yog hu ua wild type phenotype. Thaum nws hloov mus rau hauv ib tug mutant los yog ib tug txawv phenotype, nws yog hu ua forward mutation. Forward mutation confers a different phenotype than wild type phenotype.
Daim duab 01: Kev hloov pauv mus tom ntej
Kev hloov pauv mus tom ntej yuav tshwm sim hauv lacZ gene hauv E. coli, inactivates cov noob thiab ua rau nws tsis tuaj yeem loj hlob hauv nruab nrab uas muaj lactose. Kev hloov pauv rov qab ua rau cov kab mob muaj peev xwm loj hlob hauv tib qhov nruab nrab uas muaj lactose. Txawm hais tias muaj kev hloov pauv, tus nqi ntawm kev hloov mus rau pem hauv ntej yog qis heev, thiab nws nyob ib puag ncig 10-8 ib tiam.
Kev hloov pauv hloov pauv yog dab tsi?
Kev hloov pauv rov qab, tseem hu ua kev hloov pauv rov qab, yog kev hloov pauv uas thim rov qab kev hloov pauv mus tom ntej. Hauv lwm lo lus, nws yog qhov kev hloov pauv uas hloov mutant rau hauv hom tsiaj qus allele lossis phenotype. Yog li, thim rov qab hloov pauv hloov lub xeev tsis zoo ntawm cov noob rov qab mus rau lub xeev qub lossis hom tsiaj qus.
Thaum thawj nucleotide ib ntus ntawm cov noob tau rov qab los ntawm kev hloov pauv rov qab, nws tau paub tias yog qhov rov qab muaj tseeb, tab sis, nws tshwm sim tsis tshua muaj. Txawm li cas los xij, nws rov ua haujlwm li qub ntawm cov noob, cov protein ib txwm lossis cov phenotype ib txwm. Hauv ntau qhov kev hloov pauv rov qab, phenotype yog thim rov qab rau hauv cov tsiaj qus phenotype. Tsis tas li ntawd, kev hloov pauv rov qab yuav tshwm sim ntawm tus nqi qis dua li kev hloov pauv mus tom ntej. Hauv cov noob caj noob ces, cov kev ntsuam xyuas rov qab hloov pauv tau muaj txiaj ntsig hauv kev txheeb xyuas DNA kho cov noob.
Dab tsi yog qhov zoo sib xws ntawm Kev Hloov Pem Hauv Ntej thiab Rov Qab?
- Kev hloov pauv mus tom ntej thiab thim rov qab yog ob hom kev hloov pauv.
- Ob hom hloov pauv nucleotide ib ntu ntawm cov noob lossis cov genome.
Dab tsi yog qhov txawv ntawm Forward thiab Reverse Mutation?
Kev hloov pauv mus tom ntej yog kev hloov pauv uas ua rau muaj qhov sib txawv ntawm cov tsiaj qus phenotype. Hauv qhov sib piv, qhov kev hloov pauv rov qab yog qhov hloov pauv uas rov kho cov tsiaj qus phenotype los ntawm mutant phenotype. Yog li, qhov no yog qhov sib txawv tseem ceeb ntawm kev hloov mus rau pem hauv ntej thiab rov qab. Kev hloov pauv rov qab muaj txiaj ntsig zoo hauv kev txheeb xyuas DNA kho cov noob, tsis zoo li kev hloov pauv mus tom ntej.
Ntxiv mus, lwm qhov sib txawv ntawm kev hloov mus rau pem hauv ntej thiab rov qab yog qhov hloov pauv. Kev hloov pauv rov qab yuav tshwm sim ntawm tus nqi qis dua li kev hloov pauv mus tom ntej.
Summary – Forward vs Reverse Mutation
Kev hloov pauv mus tom ntej yog kev hloov pauv uas ua rau muaj phenotype txawv ntawm qhov tau txais los ntawm cov noob tsiaj qus. Hauv qhov sib piv, qhov kev hloov pauv rov qab yog qhov hloov pauv uas rov kho cov tsiaj qus-hom phenotype los ntawm thim rov qab kev hloov pauv mus tom ntej. Yog li ntawd, thim rov qab mutations undo cov teebmeem ntawm forward mutations. Yog li, qhov no yog qhov sib txawv tseem ceeb ntawm kev hloov mus rau pem hauv ntej thiab rov qab. Txawm li cas los xij, qhov kev hloov pauv rov qab yog qhov qis heev piv rau qhov kev hloov pauv mus tom ntej.
