Qhov sib txawv tseem ceeb ntawm kev hloov pauv ntawm noob thiab kev sib hloov yog qhov hloov pauv ntawm cov noob cuam tshuam nrog kev hloov pauv ntawm cov noob caj noob ces los ntawm tus neeg pub khoom noj mus rau qhov kev lees paub, thaum crossover yog kev sib pauv ntawm cov khoom siv caj ces thaum muaj kev sib deev ntawm ob homologous chromosomes ' nonsister chromatids.
Gene conversion thiab crossover yog ob lub tswv yim ntawm homologous recombination. Gene conversion yog unidirectional. Hauv kev hloov pauv gene, qhov sib npaug ntawm tus neeg pub khoom tseem nyob ntawm lub cev tsis hloov. Crossover tshwm sim nyob rau hauv ob txoj kev. Hla dhau tshwm sim thaum muaj kev sib deev thaum tsim gametes. Cov txheej txheem no suav nrog kev sib pauv ntawm cov khoom siv caj ces ntawm ob homologous chromosomes 'nonsister chromatids. Crossover tshwm sim thaum lub sij hawm pachytene substage ntawm prophase I ntawm meiosis I.
Kev hloov pauv Gene yog dab tsi?
Gene hloov dua siab tshiab yog ib lub tswv yim uas koom nrog kev hloov pauv ntawm cov ntaub ntawv keeb kwm yav dhau los ntawm tus neeg pub khoom noj mus rau qhov kev lees paub ntau homologous. Nws yog ib qho ntawm ob lub tswv yim ntawm homologous recombination. Hauv kev hloov noob caj noob ces, tus neeg pub khoom ib ntu tseem tsis hloov pauv.
Daim duab 01: Kev hloov pauv noob caj noob ces
Gene hloov dua siab tshiab tuaj yeem tshwm sim los ntawm qhov tsis zoo ntawm homologous sequences mus rau thaj tsam uas muaj ob-strand so (DSBs). Yog li ntawd, nws yog ib qho ntawm cov txheej txheem loj rau kev kho DSBs. Ntxiv mus, nws tuaj yeem tshwm sim ntawm tus muam chromatids, homologous chromosomes, thiab txawm tias ntawm homologous sequences ntawm tib chromatid los yog sib txawv chromosomes. Kev hloov noob caj noob ces yog qhov laj thawj tseem ceeb rau ntau yam kab mob ntawm tib neeg.
Crossover yog dab tsi?
Crossover yog kev sib pauv ntawm cov khoom siv caj ces ntawm cov nonsister chromatids ntawm homologous chromosomes. Nws feem ntau tshwm sim thaum meiosis. Meiosis tshwm sim thaum cov kab mob tsim cov hlwb los yog gametes. Thaum lub sij hawm meiosis, homologous chromosomes paub ib leeg thiab tsim cov khub nruj. Chromosomal crossover tshwm sim hauv cov xwm txheej no. Thaum lawv tsim tetrads, kev sib pauv cov khoom siv caj ces tshwm sim ntawm nonsister chromatids. Genetic recombination yog lub luag haujlwm rau kev hloov caj ces ntawm cov xeeb ntxwv.
Daim duab 02: Kev sib tw
Kev tsis sib xws kuj tuaj yeem tshwm sim ntawm ob homologous chromosomes. Nws tshwm sim thaum lawv tawg ntawm qhov sib txawv me ntsis. Yog li ntawd, ib chromosome tau txais ob npaug ntawm cov khoom siv caj ces thaum lwm cov chromosomes tsis tau txais ib qho. Li no, cov noob duplication tshwm sim nyob rau hauv ib chromosome, thaum lub noob deletion tshwm sim nyob rau hauv lwm yam chromosomes.
Dab tsi yog qhov zoo sib xws ntawm Gene hloov dua siab tshiab thiab Crossover?
- Kev hloov pauv thiab kev sib hloov tshwm sim feem ntau hauv meiosis.
- Ntxiv mus, lawv tuaj yeem ua tau thaum lub sijhawm mitosis thiab.
- Lawv tshwm sim hauv chromosomes ntawm eukaryotic kab mob.
- Ob leeg yog qhov tseem ceeb tsav tsheb hauv genome evolution.
- Lawv muaj lub luag haujlwm rau kev hloov pauv caj ces.
Qhov txawv ntawm Gene hloov dua siab tshiab thiab Crossover yog dab tsi?
Gene hloov dua siab tshiab yog hais txog kev hloov pauv ntawm cov khoom siv caj ces los ntawm ib qho allele mus rau lwm qhov allele (los ntawm tus neeg pub khoom noj mus rau ib qho kev lees paub). Lub caij no, crossover yog hais txog kev sib pauv ntawm cov khoom siv caj ces ntawm homologous chromosomes 'nonsister chromatids. Yog li, qhov no yog qhov sib txawv tseem ceeb ntawm kev hloov pauv ntawm noob thiab crossover. Ntxiv mus, gene hloov dua siab tshiab tshwm sim thaum lub sij hawm kho mismatch ntawm ob-strand so thaum lub sij hawm recombination. Whereas, crossover tshwm sim thaum lub sij hawm gamete tsim nyob rau hauv kev sib deev kev sib deev. Yog li, qhov no yog lwm qhov sib txawv ntawm cov noob hloov pauv thiab kev sib hloov.
Hauv qab no yog cov ntsiab lus ntawm qhov sib txawv ntawm cov noob hloov pauv thiab kev sib hloov hauv daim ntawv teev npe.
Summary – Gene Conversion vs Crossover
Gene hloov dua siab tshiab tshwm sim thaum kho ob-stranded so. Tab sis, crossover tshwm sim thaum kev sib deev ntawm kev sib deev ntawm homologous chromosomes 'nonsister chromatids. Crossover yog lub luag haujlwm rau kev txhim kho caj ces hloov pauv hauv tib neeg. Ob homologous chromosomes tau txais cov khoom siv caj ces ntawm lwm tus. Hauv kev hloov pauv noob caj noob ces, tus neeg pub khoom noj ib ntus tseem tsis hloov pauv lub cev thaum tus neeg txais ib qib tau txais cov ntaub ntawv caj ces los ntawm tus neeg pub dawb. Yog li, qhov no qhia txog qhov sib txawv ntawm cov noob hloov pauv thiab kev sib hloov.
