Qhov Tseem Ceeb Qhov txawv - Generalized vs Tshwj Xeeb Hloov
Kev hloov pauv yog ib qho kev hloov pauv DNA ntawm ib tus kab mob mus rau lwm tus kab mob los ntawm tus kab mob bacteriophage. Bacteriophage yog tus kab mob uas kis tau thiab rov ua dua hauv cov kab mob. Nws muaj peev xwm txuas mus rau phab ntsa ntawm cov kab mob thiab txhaj nws DNA rau cov kab mob. Hauv cov kab mob, cov kab mob DNA rov ua dua thiab tsim cov khoom tsim nyog thiab cov enzymes los ua cov kab mob bacteriophages tshiab. Thaum cov txheej txheem no, cov kab mob DNA degrades rau hauv daim thiab sib txuas nrog cov kab mob genome lossis, cov kab mob DNA ncaj qha koom nrog cov kab mob DNA. Cov kab mob tshiab bacteriophages dais cov kab mob DNA hauv lawv. Thaum cov kab mob bacteriophages kis rau lwm tus kab mob, sib xyaw ntawm cov kab mob DNA tshwm sim. Kev hloov pauv tuaj yeem tshwm sim los ntawm lytic voj voog lossis lysogenic voj voog raws li hom kab mob bacteriophage. Yog li, muaj ob hom kev hloov pauv uas yog kev hloov pauv dav dav thiab kev hloov pauv tshwj xeeb. Qhov sib txawv tseem ceeb ntawm kev hloov pauv dav dav thiab tshwj xeeb yog qhov kev hloov pauv dav dav yog ua los ntawm cov kab mob bacteriophages uas cov kab mob ntawm tes yog lysed thaum cov bacteriophages tshiab raug tso tawm thaum tshwj xeeb transduction yog ua los ntawm temperate bacteriophages nyob rau hauv uas cov kab mob ntawm tes tsis lysed, thiab kab mob DNA integrates nrog cov kab mob. DNA thiab ciaj sia nyob rau hauv prophage theem nyob rau hauv cov kab mob rau ntau tiam.
Dab tsi yog kev hloov pauv dav dav?
Muaj ob hom kab mob bacteriophages: virulent thiab temperate. Virulent bacteriophage muaj peev xwm tua cov kab mob hauv tsev. Lawv ib txwm ua rau lub neej voj voog lytic uas ua rau tuag ntawm tus tswv tsev kab mob. Kev kis tus kab mob los ntawm tus kab mob bacteriophage thiab xa cov kab mob DNA mus rau lwm tus kab mob thaum kis tus kab mob thib ob yog hu ua generalized transduction. Yog li, kev hloov pauv dav dav tuaj yeem txhais tau tias yog kev hloov pauv ntawm cov kab mob DNA ntawm ib tus kab mob mus rau lwm tus kab mob los ntawm cov kab mob bacteriophage thaum lub sij hawm lytic voj voog ntawm bacteriophage. Cov kab mob DNA hloov pauv tshwm sim vim qhov ua tsis raug ntawm cov khoom siv caj ces ntim hauv cov phages tshiab. Lub ntim ntawm cov tshiab DNA replicated viral mus rau hauv phages tshiab qhia tau hais tias tsis muaj fidelity. Li no, thaum lub sij hawm ntim cov khoom siv noob caj noob ces, cov khoom me me ntawm cov kab mob DNA lossis cov kab mob sib txuas nrog cov kab mob DNA tuaj yeem suav nrog hauv phages tsis raug. Yog tias cov kab mob DNA tau muab tso rau hauv cov kab mob capsid los ntawm lub caij nyoog, tus kab mob thib ob qhia cov DNA no mus rau lwm cov kab mob. Li no, kev sib hloov ua tiav ntawm ob tus kab mob ua tiav.
Tom qab kis tus kab mob, phages muaj peev xwm tswj tau cov kab mob ntawm tes kom rov ua dua nws tus kheej DNA. Tus kab mob no tseem muaj peev xwm ua kom cov kab mob chromosome degradation mus rau hauv me me thiab ua rau muaj kev cuam tshuam sai ntawm cov kab mob ntawm phab ntsa rau kev tso tawm cov phages sib sau ua rau cov cell tuag.
Txheej Txheem Kev Hloov Hloov Txheej Txheem
Kev hloov pauv dav dav yog txheej txheem ceev uas cov kab mob tuag hauv lub sijhawm luv luv. Bacteriophage muaj peev xwm rhuav tshem cov kab mob DNA mus rau hauv daim, rhuav tshem cov kab mob ntawm tes. Cov kauj ruam ntawm kev hloov pauv dav dav tuaj yeem sau tau raws li hauv qab no.
- A virulent (lytic) bacteriophage kis tus kab mob.
- Phage genome nkag mus rau cov kab mob cell.
- Virus tswj cov kab mob metabolic mechanisms ua nws tus kheej DNA thiab lwm yam khoom tsim nyog thiab enzymes.
- Kab mob DNA hydrolyses rau hauv me me.
- Cov khoom siv noob caj noob ces ntim hauv cov phages tshiab. Qee zaum cov kab mob DNA tawg pob hauv phage capsids tshiab
- Cov kab mob cell lyses thiab tso cov phages tshiab.
- Thaum transduced phage kis rau lwm tus kab mob, cov kab mob DNA yav dhau los koom ua ib qho tshiab.
Daim duab 01: Kev hloov pauv dav dav
Kev Hloov Tshwj Xeeb yog dab tsi?
Temperate bacteriophages qhia lysogenic lub neej voj voog. Lawv koom nrog cov txheej txheem kev hloov pauv tshwj xeeb uas ib feem ntawm cov kab mob DNA raug xa los ntawm ib tus kab mob mus rau lwm tus kab mob vim yog qhov yuam kev. Yog li ntawd, kev hloov pauv tshwj xeeb tuaj yeem txhais tau tias yog kev hloov pauv ntawm tus neeg pub cov kab mob DNA mus rau lwm tus kab mob los ntawm temperate bacteriophages. Thaum temperate phages kis tau cov kab mob, lawv muaj peev xwm muab cov kab mob DNA mus rau hauv cov kab mob chromosome thiab nyob twj ywm rau hauv theem prophage rau ntau tiam kab mob yam tsis tso tawm ntawm cov kab mob genome. Thaum lub sij hawm tus kab mob genome replication, kab mob DNA yog raug replication thiab nkag mus rau hauv cov kab mob tshiab thiab ciaj sia. Txawm li cas los xij, thaum cov prophages raug ntxias los ntawm qee yam, tus kab mob DNA tshem tawm ntawm cov kab mob chromosome. Qee lub sij hawm thaum lub sij hawm detachment no, cov kab mob ntawm cov kab mob chromosomes detach thiab tseem txuas nrog prophage DNA. Vim yog qhov induction, phages tau mus rau lytic voj voog tom qab. Viral genome replicates nrog cov kab mob DNA txuas nrog thiab ntim hauv cov capsids tshiab thiab ua rau phages tshiab. Tshiab phages tso cov kab mob ntawm tes los ntawm lysis. Thaum tus phage tshiab kis rau lwm tus kab mob, cov kab mob DNA hloov mus rau nws.
Tshwj xeeb kev hloov pauv
Cov kauj ruam ntawm kev hloov pauv tshwj xeeb tuaj yeem ua tiav raws li hauv qab no.
- Ib tug temperate bacteriophage kis tus kab mob.
- Viral DNA integrates rau hauv cov kab mob chromosome thiab dhau los ua theem prophage
- Viral DNA tseem nyob hauv cov kab mob rau ntau tiam
- Thaum ib qho kev tshwm sim, tus kab mob DNA tshem tawm cov kab mob chromosomal DNA.
- Cov kab mob DNA tshem tawm ntawm cov kab mob chromosome nrog cov kab mob DNA.
- Viral DNA replicates ua ke nrog cov kab mob genes thiab pob hauv capsids tshiab thiab ua phages tshiab.
- Cov kab mob cell lyses thiab tso cov phages tshiab.
- Phages tshiab kis kab mob tshiab.
- Cov kab mob DNA sib xyaw nrog cov kab mob tshiab thaum kis tus kab mob.
Daim duab 02: Kev hloov pauv tshwj xeeb qhia los ntawm lambda phage
Dab tsi yog qhov txawv ntawm Generalized thiab Specialized Transduction?
Generalized vs Specialized Transduction |
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| Kev hloov pauv dav dav yog ua los ntawm cov kab mob virus lossis lytic bacteriophages. | Kev hloov pauv tshwj xeeb yog ua los ntawm temperate phages. |
| Lifecycle | |
| Kev hloov pauv dav dav dhau mus dhau lub voj voog lytic | Kev hloov pauv tshwj xeeb dhau mus dhau lub voj voog lysogenic. |
| Lysis ntawm Bacteria | |
| Cov kab mob cell lyses sai sai. | Cov kab mob kab mob tsis lysed sai tab sis ciaj sia tau ntau tiam neeg. |
| Packaging of Genetic Material | |
| Ib feem ntawm tus neeg pub cov kab mob DNA yog nyob rau hauv kab mob capsid hauv kev hloov pauv dav dav | me me ntawm cov kab mob DNA tseem txuas nrog cov kab mob DNA thaum lub sij hawm detachment los ntawm cov kab mob chromosome thiab tau ntim rau hauv capsids tshiab. |
| Kev sib xyaw ntawm Viral DNA | |
| Viral DNA tsis koom ua ke hauv cov kab mob chromosome. | Kab mob thiab kab mob DNA sib koom ua ke. |
| Hydrolysis of Bacterial DNA | |
| Kab mob DNA hydrolyses rau hauv daim los ntawm tus kab mob. | Kab mob DNA tsis yog hydrolyzed. |
| kev tsim ntawm cov yaj saub | |
| Tsis muaj kev tshaj tawm thaum lub sijhawm hloov pauv dav dav. | Prophages yog tsim thaum lub sij hawm tshwj xeeb transduction. |
Summary – Generalized vs Specialized Transduction
Kev hloov pauv yog txheej txheem hloov cov kab mob DNA los ntawm ib tus kab mob mus rau lwm tus los ntawm tus kab mob. Nws yog cov txheej txheem ntuj tsim los ntawm lytic lossis lysogenic cycles. Virulent phages qhia txog kev hloov pauv dav dav. Temperate phages qhia kev hloov pauv tshwj xeeb. Thaum lub sij hawm kev hloov pauv dav dav, tus kab mob no rhuav tshem cov kab mob ntawm tes. Hauv kev hloov pauv tshwj xeeb, cov kab mob hlwb tsis raug puas tsuaj sai heev tshwj tsis yog tias muaj qhov induction. Qhov no yog lub ntsiab sib txawv ntawm generalized thiab tshwj xeeb transduction. Viral DNA integrates rau hauv cov kab mob chromosome nyob rau hauv tshwj xeeb transduction thiab kev koom ua ke tsis tshwm sim nyob rau hauv generalized transduction.
