Ho Kopanngoa ha Liphatsa tsa Lefutso ho Biology ea Limolek'hule
Ho kopanya liphatsa tsa lefutso ke e 'ngoe ea lits'ebetso tsa bohlokoa ka ho fetisisa baelojing ea limolek'hule, e lumellang thepa ea liphatsa tsa lefutso ho fapanyetsana, ho hlophisoa bocha, kapa ho kopanya hape. Ts'ebetso ena e bapala karolo e kholo ho etseng phapang ea liphatsa tsa lefutso, ho boloka botsitso ba genome, le ho lokisa tšenyo ea DNA. Linthong tse phelang—ho tloha libaktheria ho ea ho batho—ho kopanya hape ke sesebelisoa sa tlhaho sa ho boloka ho phela le ho ikamahanya le liphetoho tsa tikoloho. Moelelong oa baeloji ea limolek'hule ea sejoale-joale , ho utloisisa ho kopanya hape liphatsa tsa lefutso ho boetse ho theha motheo oa mahlale a fapaneng a kang boenjiniere ba liphatsa tsa lefutso, 'mapa oa liphatsa tsa lefutso le phekolo ea liphatsa tsa lefutso.
Ho Utloisisa ho Kopanngoa ha Liphatsa tsa Lefutso
Ha re bua ka bokhutšoanyane, ho kopanya liphatsa tsa lefutso ke mokhoa oa ho fapanyetsana likarolo tsa DNA pakeng tsa limolek'hule tse peli tsa DNA kapa li-chromosome tse peli. Sephetho ke motsoako o mocha oa liphatsa tsa lefutso o fapaneng le tokisetso ea pele. Ho kopanya liphatsa tsa lefutso ho ka etsahala ka tlhaho liseleng (mohlala, nakong ea ho thehoa ha gamete ho li-eukaryotes) kapa ho ka etsoa laboratoring (mohlala, ho sebelisoa mekhoa ea DNA e kopanyang liphatsa tsa lefutso).
Ts'ebetso ena e bohlokoa hobane DNA ha se sebopeho se sa fetoheng. Genome e tobana le liphephetso tse sa khaotseng: ho ikatisa ho sa phethahalang, ho pepesehela mahlaseli, lik'hemik'hale le likhatello tsa khetho. Ho kopanya hape ho thusa ho hlola liphephetso tsena ka ho lokisa le ho hlophisa bocha tlhahisoleseling ea liphatsa tsa lefutso.
Mefuta ea ho Kopanya Liphatsa tsa Lefutso
Ho baeloji ea limolek'hule , ho kopanya liphatsa tsa lefutso hangata ho arotsoe ka mefuta e 'maloa e meholo:
1. Ho kopanya hape ho tšoanang
Ho kopana ha di-homologous ho etsahala pakeng tsa dimolekhule tse pedi tsa DNA tse nang le tatellano e tshwanang haholo kapa e tshwanang. Ena ke mokgwa wa bohlokwa ho meiosis ho di-eukaryote, o hlahisang phapang ya dijini ho bana. Ho phaella moo, ho kopana ha di-homologous le hona ho bapala karolo ya bohlokwa. tokisong ea DNA, haholo-holo tokisong ea ho robeha ha likhoele tse peli.
Mohlala o tsebahalang haholo ke "ho tšela" nakong ea prophase I ea meiosis, ha li-chromosome tse tšoanang li fapanyetsana likarolo. Phapanyetsano ena e eketsa mefuta-futa ea liphatsa tsa lefutso 'me e thusa karohano ea li-chromosome ho tsoela pele ka mokhoa o tloaelehileng.
2. Ho kopanya hape ho seng ho tšoanang
Ho fapana le ho kopana ha di-homologous, ho kopana ha di-homologous ho sa hloke ho tshwana ho hoholo ha tatellano. Tshebetso ena e ka baka diphetoho tse kgolo ho genome, tse kang ho hlakolwa, ho pheta-pheta, ho fetoha ha di-inversion, kapa ho fetela dibakeng tse ding. Maemong a mang, ho kopana ha di-homologous ho ka ba le ditlamorao tse mpe, tse bakang diphetoho kapa ho se tloaelehe ha di-chromosome.
Mokhoa o mong o amanang le ona ke Non-Homologous End Joining (NHEJ), mokhoa oa hore lisele li lokise ka potlako ho robeha ha DNA e nang le marapo a mabeli ka ho kopanya lipheletso tsa DNA ka ho toba. Leha e sebetsa hantle, NHEJ e atisa ho ba kotsi hobane e ka fella ka liphoso tse nyane tse kang tahlehelo kapa ho eketsoa ha li-nucleotide tse 'maloa.
3. Ho kopanya hape sebaka se itseng
Ho kopana hona ho etsahala libakeng tse itseng tsa DNA tse tsejoang ke lienzyme tse khethehileng. Mokhoa ona o tloaelehile livaeraseng, li-plasmids, le libaktheriaMohlala, ha phage (vaerase ea baktheria) e kenya genome ea eona ka har'a chromosome ea baktheria, lienzyme tse amehang hangata li bitsoa li-recombinase, tse khaolang le ho kopanya DNA tatellanong ea sepheo.
Ho kopanya hape sebaka se itseng ho na le bohlokoa ba bohlokoa theknolojing ea baeloji hobane ho lumella ho fetoloa ha DNA ka nepo haholoanyane, mohlala, tsamaisong ea Cre-Lox e tsebahalang lipatlisisong tsa liphatsa tsa lefutso.
Mokhoa oa ho Kopanya Limolek'hule
Ho utloisisa ho kopana ha liphatsa tsa lefutso, ho bohlokoa ho utloisisa mekhoa ea eona boemong ba limolek'hule. Leha lintlha li ka fapana ho latela mofuta oa ho kopana ha liphatsa tsa lefutso, mehato e meng e akaretsang e ka hlalosoa.
Ho kopanngoa ha DNA ka tsela e tšoanang, ts'ebetso hangata e qala ka ho robeha ha DNA ka tsela e habeli. Sele ebe e feta "ts'ebetsong ea ho qetela" ho hlahisa lipheletso tsa DNA tse nang le tsela e le 'ngoe. Lipheletso tsena li batla li-homologous tatelano ho li-chromosome tse ling, e leng se lebisang tlhaselong ea likhoele, e leng se etsang meaho e tšoanang le "D-loops." Sena se theha kopano ea Holliday, sebopeho sa DNA se hokahaneng se ka khaoloang le ho kopanngoa hape, se hlahisa metsoako e mecha ea liphatsa tsa lefutso.
Liprotheine tsa bohlokoa ts'ebetsong ena li kenyelletsa RecA libaktheriang le Rad51 ho li-eukaryote. Liprotheine tsena li thusa ho hokahanya tatellano ea li-homologous le ho nolofatsa phapanyetsano ea likhoele tsa DNA.
Ho sa le jwalo, ho NHEJ, dipheletso tsa ho robeha ha DNA di lemohuwa ka diprotheine tse tlamang qetellong, ebe di kopanngwa le ho kopanngwa hape. Mokgwa ona ha o hloke template e tshwanang, e leng se etsang hore e be kapele empa e se nepahale hakaalo.
Karolo ea ho Kopanya Liphatsa tsa Lefutso ka Mefuta-futa
Ho kopanya hape ke mohloli o moholo oa phapang ea liphatsa tsa lefutso ho baahi. Ho li-eukaryotes, meiosis e hlahisa li-gametes tse nang le metsoako e fapaneng ea li-allele. Ho tšela ho hlahisa li-chromosome tse nang le motsoako oa liphatsa tsa lefutso ho tsoa ho batsoali ka bobeli. Sena se bohlokoa bakeng sa ho iphetola ha lintho hobane phapang ea liphatsa tsa lefutso e fana ka "thepa e tala" bakeng sa khetho ea tlhaho ho sebetsa.
Leha libaktheria li sa fete meiosis, ho kopana hape ho ntse ho etsahala ka mekhoa ea phetisetso ea liphatsa tsa lefutso tse rapameng joalo ka phetoho (ho nka DNA tikolohong), phetisetso (e tsamaisoang ke livaerase), le ho kopana (ho fetisetsa li-plasmid lipakeng tsa lisele). Mekhoa ena e lumella libaktheria ho fumana litšobotsi tse ncha ka potlako, joalo ka ho hanyetsa lithibela-mafu.
Ho Kopanya le ho Lokisa DNA
Ho kopanya liphatsa tsa lefutso ha ho bake feela phapang empa hape ho bapala karolo ea ho boloka botšepehi ba liphatsa tsa lefutso. Ho arohana ha DNA ka likhoele tse peli ke e 'ngoe ea mefuta e kotsi ka ho fetisisa ea tšenyo hobane e ka lebisa tahlehelong ea tlhahisoleseling ea liphatsa tsa lefutso le lefu la sele. Ho kopanya ho tšoanang ho ka lokisa likhoele tsena ka nepo ka ho sebelisa li-chromatids tsa khaitseli e le litempele. Kahoo, ho kopanya hape ke mokhoa oa bohlokoa oa "tlhokomelo" bakeng sa ho phela ha lintho tse phelang.
Liphoso tsa ho kopanya hape li ka lebisa mafung a fapaneng. Ho batho, ho sitisoa ha mekhoa ea ho lokisa DNA ka ho kopanya hape ho ka eketsa kotsi ea kankere ka lebaka la ho bokellana ha liphetoho tsa lefutso. Liphetoho tsa lefutso tsa BRCA1 le BRCA2, mohlala, li amahanngoa le ho se lokisoe ha DNA le kotsi e eketsehileng ea kankere ea matsoele le ea mahe a bomme.
Ho kopanya hape theknoloji ea baeloji le boenjiniere ba liphatsa tsa lefutso
Polelwana "recombinant DNA" hangata e sebediswa theknolojing ya baeloji, e leng se bolelang DNA e kopantsweng ho tswa mehloding e mmedi e fapaneng. Mokgwa ona o dumella dijini tse itseng ho kenngwa ka hara di-plasmid, ebe di kenngwa ka hara dibaktheria kapa disele tse ding bakeng sa tlhahiso. Ka tsela ena, batho ba ka hlahisa diprotheine tsa bohlokwa tse kang insulin, dihormone tsa kgolo, kapa diente.
Ho phaella moo, ho kopanya hape ho sebediswa ho theheng diphedi tse fetotsweng lefutso, ho etsa 'mapa wa dijini, le tlhahiso ya dijalo tse nang le dibopeho tse hodimo (mohlala, ho hanyetsa dikokonyana kapa ho mamella komello). Diphuputsong, mekgwa ya ho kopanya hape e ikgethang sebakeng se itseng jwalo ka sistimi ya Cre-Lox e dumella bo-rasaense ho "tima" kapa ho "bulela" dijini tse itseng dinama le dinakong tse itseng, ka hona ho dumella thuto e nepahetseng haholoanyane ya tshebetso ya dijini.
Nts'etsopele ea theknoloji ea CRISPR-Cas9 e boetse e kenyelletsa ho kopanya hape. Kamora hore DNA e khaoloe ke Cas9, lisele li ka lokisa lekhalo ka NHEJ kapa ho lokisa homology-directed repair (HDR), e sebelisang melao-motheo ea ho kopanya hape ho homologous ho kenya tatellano e lakatsehang.
Qetello
Ho kopanya liphatsa tsa lefutso baelojing ea limolek'hule ke ts'ebetso ea bohlokoa e hokahanyang phapang ea liphatsa tsa lefutso, tokiso ea DNA le botsitso ba genome. Ho kopanya liphatsa tsa lefutso tse tšoanang ho thusa ho hlahisa mefuta-futa ha ka nako e ts'oanang ho lokisa tšenyo ea DNA ka nepo, ha ho kopanya tse seng tsa ho lekana le tse ikhethileng sebakeng se itseng ho bapala karolo ea bohlokoa ho matla a genome le likamano lipakeng tsa lintho tse phelang tse kang libaktheria le livaerase. Mehleng ea kajeno, ho utloisisa ho kopanya liphatsa tsa lefutso ho lebisitse ho mefuta e mengata ea lits'ebetso tsa biotechnology, ho tloha tlhahisong ea lithethefatsi ho ea ho editing ea liphatsa tsa lefutso. Ha lipatlisiso lefapheng lena li ntse li tsoela pele, ho kopanya liphatsa tsa lefutso ho tla lula e le sehlooho sa bohlokoa ho utloisiseng bophelo boemong ba limolek'hule le ho nts'etsapele litharollo tsa liphephetso tsa bophelo bo botle le lijo nakong e tlang.
