Transduction - menene wannan?

были описаны в разное время. Sake Kama da transduction aka bayyana a lokuta daban-daban. A karshen da aka bude a 1952. Wannan labarin zai dubi abin ne daban-daban na transduction, abin da siffofi da suka yi da kuma inda aka yi amfani da wannan sabon abu.

A farko nazarin

A matsayin dalibi, N. Tsinder aiki a Lederberg Lab karatu gaban Tasrifu a Salmonella typhimurium. Ya yi amfani da 20 monoauksotrofnyh ta damuwa. Lokacin da su ne gauraye pairwise masanin kimiyya kokarin gane prototrophic zuriyarsa. A 9 lokuta, da kwafi masu kunnen doki da wadannan Kwayoyin da aka gano a cikin 79 haduwa. Saboda gaskiya cewa babu wani daga cikin asali iri ba su samar da repertantov a kan kadan matsakaici Tsinger ƙarasa da cewa tsakanin su ne da za'ayi Tasrifu, a lokacin da kwayoyin bayanai da aka canjawa wuri.

Don tabbatar da jarrabawa, da Lederberg, ya maimaita gwaji na Davis da U-dimbin yawa tube raba gilashi tace cewa ta kawar da sel kwayoyin. A binciken da amfani da damuwa na Salmonella typhimurium 2Ahis- da 22Atrp-. A daya reshe shambura 22A Bears al'adu na iri zuwa wani - 2A. Dukansu sun a maida hankali 1 • 108 Kwayoyin / ml. Bayan da shiryawa zamani, da abun ciki rabo 22A damuwa aka gano prototrophic Kwayoyin. Su aka kafa a mita na 1 • 10-5. A sauran reshe shambura prototrophic Kwayoyin kasance mãsu fakowa ba.

A gwaji sakamakon bai tabbatar da jarrabawa na Tasrifu canja wurin bayanai daga 22A kuma 2A damuwa.

Transduction: The Experience

A lokacin m dubawa an gano cewa, da iri 22A kamu da phage P22. Shi ne iya harba da kuma lyse Kwayoyin Salmonella typhimurium 2A. Iya shiga ta hanyar da tace, shi ya cutar da Kwayoyin, sake fitarwa da dissolves su. Tare da wannan saki da tacewa faru wakili (as shi ne ake kira Lederberg da Tsinger). Ya, bi da bi, ya zo ta hanyar gilashi. Ƙarƙashin rinjayar da tacewa wakili, wasu daga cikin sel a cikin zuriya 22A yakan mallaki takamaiman hereditary halaye. Sun kasance sũ ne kamar irin waɗanda ba a cikin iri 2A, daga wanda tsaya fitar da FA.

A musamman shi saukar da ikon haduwa tryptophan. An tabbatar da cewa tacewa wakili na ayyuka ba a rasa a lokacin sarrafa shi DNase. Wannan gusar da yiwuwar canji. An gano cewa tacewa kaddarorin da wakili sun m phage P22. Yana kammala daga wannan cewa karshen daukawa bayanai a kan iri 22A zuwa 2A, wanda aiki a matsayin shaida na kwayoyin rawar da nucleic acid.

Transduction da aka gabatar a matsayin ra'ayi don bayyana wannan sabon abu kayyade watsa bayanai.

The bayani dalla-dalla na aiwatar

специфичное явление, при котором осуществляется перенос генетической информации от клетки-донора к клетке-реципиенту при помощи фага . Transduction - wani takamaiman abu a wanda za'ayi da canja wurin da kwayoyin bayanai daga wani mai bayarwa cell ga mai karɓa cell amfani phage. Ya dogara ne a kan gaskiyar cewa a cikin shakka daga haifuwa na phages za a iya kafa na barbashi. Tare da ko maimakon DNA da suka hada da wasu taragutsan da aka mai suna transduced. A cewar ta adsorption Properties da ilimin halittar jiki ne kama da na al'ada phage virions. Duk da haka, idan sun harba sabon Kwayoyin, akwai wani canja wuri da kwayoyin determinants na karshe mai shi. transduction inji haka kunshi a cikin wadannan. Domin canja wuri da kwayoyin determinants zama dole su gudanar da multiplication na phage ga sel da bayarwa iri. Sa'an nan, sakamakon fagolizat da za a gabatar a cikin mai karɓa Kwayoyin. Selection na transductants ne da za'ayi a zabe kafofin watsa labarai. A cikin farko mai karɓa Kwayoyin ba zai iya girma.

rarrabuwa

A nazarin sabon abu an gano cewa wasu phages suna da ikon aika daban-daban kwayoyin halitta, da sauransu - kawai takamaiman. Haka kuma, iri biyu canja wurin bayanai da aka kasaftawa:

1. Jimlace transduction. явление предполагает передачу любого фрагмента хромосомы. Wannan sabon abu ya shafi canja wuri na wani ɓaɓɓake daga wani chromosome.
2. Specific hijirarsa. A wannan yanayin, kawai wasu kwayoyin halittu aka canjawa wuri.

Nonspecific (jimlace) tsari

Abin da siffofin a cikin wannan yanayin yana da wani transduction? явление имеет место при наличии вируса, выступающего только в качестве переносчика материала. Wannan abu ya faru a gaban cutar, abubuwa ne kawai a matsayin m abu. Daya daga cikinsu - ya ce phage P22. Lederberg yi aiki tare da shi da kuma Zinger. PBS1 B. Subtilis, Р1 E. Coli и проч. Bugu da kari, phages, wanda za'ayi kowa yana da transduction - shi ne PBS1 B. Subtilis, P1 E. coli, da sauransu. A tsari faruwa tare da sa hannu na m barbashi. Da samuwar wadannan abubuwa na faruwa a haifuwa phages tare da Lalacewar kwayan chromosomal DNA. Ya kamata a lura da cewa su samuwar zai iya faru a lytic ci gaba da kuma bayan prophage shigar da. A wasu yawan barbashi cushe da kwayan DNA. The girma na ta da wani ɓaɓɓake daina shugaban size. Kamar wancan ne da sassa daban-daban za a iya cushe tare a kan kwayan chromosome. A phage barbashi da cewa kawo DNA da wani ɓaɓɓake, kira a matsayin m.

recombination

Idan fagolizatom, wanda ya ƙunshi biyu al'ada da kuma transducing, niƙaƙƙun gaɓãɓuwa yi wa Kwayoyin mai karɓa iri, da kamuwa da cuta daga al'ada phage yawanci take kaiwa zuwa lysis (rushe). Amma wasu Kwayoyin suna kamu da m aka gyara. A tsarin zo short guda na biyu-stranded DNA daga bayarwa. Kamar wancan circularization faruwa. A wasu kalmomin, da mikakke DNA da wani ɓaɓɓake daga bayarwa recombine tare da DNA daga mai karɓa. Wannan tsari ne da sarrafawa da recA-gene. Saboda haka, shi ne wani janar homologue recombination, wanda aka ɗauke da na juna (juna) musayar dacewa homologue sassa.

takamaiman tsari

Transduction na irin wannan da aka samu a 1956. Its peculiarity shi ne cewa kowane phage watsa sosai iyaka, musamman yankin na chromosome. Idan nonspecific phage transduction - "m" vector kayyade abu, da kuma recombination ya auku a kan dokokin general, a wannan yanayin, shi ba kawai watsa bayanai, amma kuma samar da shigarwa cikin chromosome. Mafi shahara misali aikin wani tsari, Madĩna da phage λ. Shi ne iya infecting sel E. coli tare da kara hadewa da DNA cikin genome. Wannan temperate phage da kwayoyin cuta a lizogenezatsii site-takamaiman recombination (ga wanda rata da giciye-Haša haihuwarka kwayoyin) kafa a cikin chromosome a daya kawai rabo - tsakanin bio- da gal-loci. Mai yiwuwa, wannan ne ya sa ta "ba daidai ba" ya samar da wata madauki a cikin prophage rarrabuwa. Saboda wannan yankin na genome m cikinta, cleaved daga chromosome tsarin da ya wuce a cikin free phage. Recessed abu zai iya maye gurbin zuwa 1/3 na kayyade bayani. Bayan marufi m phage DNA barbashi kafa.

Filayen da amfani

Transduction na kwayoyin cuta da za a iya amfani da:

1. A zayyana wani musamman genotype damuwa, isogenic, musamman. A wannan yanayin da kananan yawa na daukar kwayar cutar barbashi samar da wani amfani transduction aiwatar da Tasrifu. Isogeneic damuwa generated amfani generalizatsionnoy canja wurin kayan bambanta kawai a cewa rabo daga chromosome cewa daukawa mai m phage.
2. Ga cikakken Taswirar genes na kwayoyin kafa tsari na su jeri a operons, da kudin tsarin wasu determinants. Wannan yana cika ta hanyar complementation gwajin. An gano cewa, ga rairaya wasu kayayyakin bukatar aikin da dama kwayoyin halittu. Alal misali, da tsari ne m da aka gyara na Tsarin wani kuma b. Zaton akwai biyu phenotypically kama rikidaddu suna iya haduwa da enzyme. Shi ne ba a sani ba, shin, sũ suke sãɓa genetically. Don gane da genotype kwashe transduction, Ina nufin phage multiplication a kan Kwayoyin a cikin wannan yawan, bi da kamuwa da cuta da abubuwa na biyu. Idan allura a cikin zabe matsakaici samar duka biyu manyan da kananan mallaka transdukantov, shi ne ƙarasa da cewa sarrafawa daga cikin maye gurbi ne a daban-daban da kwayoyin halittu.
3. Lokacin da transdutsirovanii plasmids da bayarwa short jẽfo wani ɓaɓɓake daga chromosomes.

bugu da žari

A adabi ne sau da yawa amfani da irin wannan abu a matsayin "siginar transduction". Yana wakiltar siginar watsa. A tsari faruwa a wasu juna. Na farko, da waje wakili interacts da salon salula tsoka mai amsa sigina. Sa'an nan kunna effector kwayoyin. An located a cikin membrane kuma shi ne alhakin da samuwar biyu manzanni. Su tsara na taimaka wa kunnawa da manufa da sunadarai. Su, bi da bi, fararwa da wadannan shamaki ba.