Ukushintshwa yikuphi?

были описаны в разное время. Ukuguqulwa nokuguqulwa kuye kwachazwa ngezikhathi ezahlukene. Leli gama lavuleka ngo-1952. Kulesi sihloko sizocubungula ukuthi yiziphi izinhlobo zokudluliswa ezikhona, ukuthi yiziphi izici abanakho futhi lapho lokhu kusetshenziswe khona.

Izifundo zokuqala

Eminyakeni yakhe yokufunda uN. Zinder, esebenza laboratory yeLederberg, wayefundela ukukhonjwa kweSalmonella typhimurium. Wasebenzisa izinhlobo ezingu-20 ze-monaauxotrophic. Lapho ebahlanganisa ndawonye, usosayensi wazama ukuthola inzalo ye-prototrophic. Ezimweni ezingu-9 zokuhlanganiswa ezingu-79, ama-cell of cells anjalo atholakele. Ngenxa yokuthi ayikho imithwalo yangempela eyenza abantu ababuyiselwe endaweni ephansi, uZinger waphetha ngokuthi ukuhlanganiswa kwenziwa phakathi kwabo, lapho ulwazi oludluliselwa khona ludluliselwa khona.

Ukuze uqinisekise i-hypothesis, kanye no-Lederberg, uphinde wahlola ukuzama kukaDavis esebenzisa ithubhu efana no-U ehlukaniswe isihlungi seglasi esingavumeli ukuthi amaseli ezincane ezincane azidlule. Ucwaningo lwalusebenzisa izinhlanzi ze-Salmonella typhimurium 2Ahis- no-22Atrp-. Umkhuba we-strain 22A wangena egatsheni elilodwa le-tube test, kwenye-2A. Zombili zazingxenyeni 1 • 108 amaseli / ml. Ngemuva kwesikhathi sokutshala, iyingxenye ene-22A iveza amangqamuzana e-prototrophic. Zakhiwe ngezimpawu zoku-1 • 10-5. Kwelinye igatsha le-tube, amangqamuzana e-prototrophic ayengekho.

Imiphumela yokuhlolwa ayiqinisekisi ukucabanga kokudluliswa kolwazi kolunye uhlobo ku-strain 22A no-2A.

Ukuguqulwa: Okuhlangenwe nakho

Ngesikhathi sokuhlolwa okulandelayo, kwafunyanwa ukuthi i-22A ye-22A igciwane lesifo se-P22. Iyakwazi ukutheleleka futhi ilayise amangqamuzana e- Salmonella typhimurium 2A. Ukungena ngaphakathi kwesihlungi, wathola amangqamuzana, wakhiqiza futhi wawahlakaza. Ngesikhathi esifanayo, kukhishwe i-agent yokuhlunga (njengoba uLederberg noZinger bakubiza). Yena, naye, wangena egumbini. Ngaphansi kwethonya le-agent yokuhlunga, amanye amaseli asebunzima 22A athola izici ezikhethekile zokufa. Babefana nalabo ababesekhona ku-2A, lapho i-FA yayimfihlo khona.

Ngokuyinhloko, ikhono lokwenza i-tryptophan livezwe. Kwakunqunywa ukuthi umsebenzi we-agent yokuhlunga awulahlekile ngesikhathi ukwelashwa nge-DNase yayo. Lokhu kwaqeda ithuba lokuguqulwa. Kwasungulwa ukuthi izindawo ze-agent ehlunga zifana nalabo be-phage P22. Kusukela kulokhu kwaphetha ngokuthi lesi sigaba sithatha ulwazi oluvela ku-22A kuya ku-2A, olusebenza njengobufakazi bendima yefadi ye-nucleic acid.

Ukuguqulwa njengombono wethulwa ukubhekisela kulesi simo sokudluliswa kwedatha yezofuzo.

Inqubo ecacile

специфичное явление, при котором осуществляется перенос генетической информации от клетки-донора к клетке-реципиенту при помощи фага . Ukuguqulwa kuyisimo esithile lapho imininingwane yezofuzo idluliselwa kusuka esitokisini somnikelo kumuntu owemukelayo ngomakhalekhukhwini . Isekelwe eqinisweni lokuthi ngesikhathi sokuphindaphinda kwamaphakheji, izinhlayiya zazo zingakha. Kanye noma esikhundleni se-DNA, zifaka ezinye izingcezu futhi zibizwa ngokuthi i-transducers. Ngokwezici zabo zokukhangisa kanye ne-morphology, zifana nezigaba ezijwayelekile ze-phage. Kodwa-ke, uma befaka amangqamuzana amasha, izakhi zofuzo zesikhathi esidlule ziyadluliselwa. Indlela yokwedlulisa, ngaleyo ndlela, ingendlela elandelayo. Ukuze kudluliselwe izakhi zofuzo, kuyadingeka ukwandisa isigaba kumaseli omnikeli womnikeli. Emva kwalokhu, i-phagolysate eholelekile ifakwe kumaseli atholakele. Ukuzikhethela kwe-transductants kwenziwa emithonjeni yokukhetha. Kuzo, amaseli wokutholwa ayengakwazi ukukhula.

Ukuhlukaniswa

Lapho ufunda lo mkhuba kwatholakala ukuthi amaphakheji athile anekhono lokudlulisa izakhi zofuzo ezihlukene, kuyilapho abanye - okukhethekile kuphela. Ngokuhambisana nalokhu, izinhlobo ezimbili zokudluliswa kwedatha ziyahlukaniswa:

1. Ukushintshwa okujwayelekile . явление предполагает передачу любого фрагмента хромосомы. Lesi simo sihilela ukudluliselwa kwanoma yisiphi isici se-chromosome.
2. Ukudluliswa okuqondile. Kulesi simo, izakhi ezithile zegciwane ziyadluliselwa.

Inqubo engajwayelekile (jikelele)

Yiziphi izici ezithinta ukudluliselwa kulokhu ? явление имеет место при наличии вируса, выступающего только в качестве переносчика материала. Lesi senzakalo senziwa phambi kwegciwane elisebenza nje kuphela njengomphathi wezinto ezibonakalayo. Enye yazo i-phade ekhonjiwe ngenhla P22. ULederberg noZinger basebenze naye. PBS1 B. Subtilis, Р1 E. Coli и проч. Ngaphezu kwalokho, amaphakheji okuhanjiswa kuwo wonke ama- PBS1 B. Subtilis, P1 E. Coli njalonjalo. Le nqubo iqhubeka nokubandakanya izinhlayiya ezingaphelele. Ukwakhiwa kwalezi zakhi kwenzeka ngesikhathi sokukhiqizwa kwamaphakheji, kuhambisana nokubola kwe-bacterium chromosomal DNA. Kumele kuqashelwe ukuthi ukubunjwa kwabo kungenziwa kokubili ekuthuthukisweni kwabo nangemva kokufakwa kwe-prophage. Inani elithile lezinhlayiyana ligcwele i-DNA yebhaktheriya. Ubukhulu bezingcezu zalo akulona ubuningi bekhanda. Kulesi simo, izingxenye ezihlukahlukene ze-chromosome yebhaktheriya zingafakwa. Izinhlayiyana zephage ezithwala izidakamizwa ze-DNA zibizwa ngokuthi ziyiziphambeko.

Ukunciphisa

Uma i-phagolysate, lapho kutholakala khona izicucu ezivamile nezidlulisayo, uphathe ama-cell of the receptor strain, bese ukutheleleka nge-phage yabo evamile kuvame ukuholela ku-lysis (ukuchithwa). Kodwa amanye amaseli afaka izingxenye ezingaphelele. Izingxenye ezimfushane ze-DNA kabili elinezintambo ezivela kumnikezeli zifaka izakhiwo. Ngesikhathi esifanayo, akukho ukujikeleza. Ngamanye amazwi, izingcezu ezilinganiselwe ezivela ku-DNA yomnikeli zihlanganisa i-DNA evela kumamukeli. Le nqubo ilawulwa yi-recA-gene. Ngakho-ke, ukubuyiswa kwe-homologous jikelele, okufezwa ngokushintshaniswa (kokubili) kokunye izingxenye ze-homologous ezihambisanayo.

Inqubo ecacile

Ukukhishwa kwalolu hlobo kutholakala ngo-1956. Ukuziqhenya kwalo ukuthi i-phage ngayinye idlulisela isifunda esinqunyiwe, esithile esithile se-chromosome. Uma lo phapha lubizwa ngokuthi "umthumbi" onguchwepheshe wezakhi zofuzo, kanti ukubuyiswa komzimba kuqhubeka ngokulandela amaphethini ajwayelekile, ngakho-ke kulokhu akudlulisanga kuphela ulwazi, kodwa futhi kuqinisekisa ukungena kwe-chromosome. Isibonelo esidume kunazo zonke inqubo eyenziwe yi-phage λ. Iyakwazi ukuthelela ama-E. coli amangqamuzana ngokuhlanganiswa okuqhubekayo kwe-DNA ku-genome. Le phage elinganisiwe ku-lysogenesis yebhaktheriya ekuqothulweni okuqondene nesayithi (ephula futhi ewela emaketeni e-molecule) yakhiwe ngaphakathi kwe-chromosome kuphela kwenye isayithi - phakathi kwe-bio ne-gal-loci. Kungenzeka ukuthi lokhu kubangelwa ukwakheka okungalungile kwe-loop ngenkathi ukuhlakazeka kwe-prophage. Ngenxa yalokho, isifunda se-genome esiseduze nayo sincike esakhiweni se-chromosome futhi siba yi-phage yamahhala. Izinto ezihlanganisiwe ziyakwazi ukufaka esikhundleni se-1/3 yolwazi lofuzo. Ngemva kokupakisha i-DNA yephageji, izinhlayiya ezingaphelele zakhiwa.

Izikhombisi zokusetshenziswa

Ukwedluliselwa kwamabhaktheriya kungasetshenziswa:

1. Uma ukwakhiwa kwezinhlobo ze-genotype ethize, isogenic, ikakhulukazi. Kulokhu, inani elincani lezinhlayiya ezidluliselwayo linikeza inzuzo yentuthuko ngaphambi kokuba inqubo yokucubungula. Izinkinga ze-isogenic ezakhiwe ngokukhiqiza ukukhiqiza kwezinto ezihlukile kuleyo ngxenye ye-chromosome edluliselwa yi-phage engalungile.
2. Ukuze udwebe ngokunembile izakhi zofuzo zamabhaktheriya, faka umyalelo wokubekwa kwawo kuma-operon, isakhiwo esihle sezimpawu ezithile. Lokhu kwenziwa ngokusebenzisa ukuhlolwa kwe-complementation. Kuye kwasungulwa ukuthi ukuhlanganiswa kwemikhiqizo ethile kudinga umsebenzi wezakhi eziningana. Isibonelo, inqubo inqunywa yizingxenye zezakhiwo a futhi b. Ake sithi kunezinhlobo ezingu-2 ze-phenotypically eziguquguqukayo ezingenakwenzeka zokwenza i-enzyme. Ayaziwa ukuthi ziyahluka yini izakhi zofuzo. Ukuthola i-genotype, ukudluliselwa kwenziwa, okungukuthi, ukuphindaphinda kokuphakanyiswa kwamangqamuzana emphakathini owodwa, kulandelwa ukutheleleka kwezakhi zesibini. Uma ama-coloni amakhulu nezincane ze-transducers akhiwa ngendlela ekhethayo, kuphetha ngokuthi indawo yokuguqulwa kwezinto ezakhiwe ngezakhi zofuzo ezahlukene.
3. Lapho kudluliselwa ama-plasmids namaqhezu amancane ama-chromosomes abanikeli.

Okuthuthukisiwe

Lezi zincwadi futhi zivame ukusebenzisa umqondo onjalo ngokuthi "ukudluliselwa kwesignali". Kuyinto yokudluliselwa kwesignali. Inqubo ilandela iphethini ethile. Okokuqala, i-agent yangaphandle ixhumane ne-receptor yeselula. Emva kwalokho, i-molecule yomsindo ivuliwe. Itholakala embundwini futhi inesibopho sokwakhiwa kwezihambeli eziyisibili. Isizukulwane sabo sithuthukisa ukuqaliswa kwezinjongo zamaprotheni. Bona, nabo, baqalise abaxhumanisi abalandelayo.