Molecular Biology Cell Cycle PDF

Uhlaziyo lokugqibela: 30/08/2023
Umbhali: USebastian Vidal

Ibhayoloji yemolekyuli yomjikelezo weeseli yindawo enomdla yokufunda egxile ekuqondeni iindlela kunye neenkqubo ezilawula umjikelo wobomi beseli ukuphuhliswa konyango olujoliswe kwimfuza kunye nokuphazamiseka kwe-carcinogenic. Kweli nqaku, siza kuphonononga iziseko zebhayoloji yemolekyuli yomjikelo weseli, iqaqambisa ukubaluleka kwayo kunye nokubonelela ⁢a⁢ indlela yobuchule evumela ukuqonda okunzulu⁣ kweengqiqo ezibandakanyekayo. Ngokukodwa, siya kugxininisa kumjikelo weseli en Ifomathi yePDF, ukubonelela ngesixhobo esixabisekileyo kwabo banomdla kuphando kunye nokufunda kweli candelo.

1. Intshayelelo kwibhayoloji yemolekyuli yomjikelo weseli

Ibhayoloji yemolekyuli ye umjikelo weseli Ngummandla onika umdla nontsokothileyo ophonononga ⁢iinkqubo ezingundoqo ezenzeka⁣ kwiseli njengoko isahlula kwaye ivelisa kwakhona. Ukuqonda ezi ndlela kubalulekile ukuqonda ukukhula okuqhelekileyo kunye nophuhliso lwezinto eziphilayo, kunye nokujongana nezifo ezinxulumene nokwahlulwa kweeseli ezingalawulwayo, ezifana nomhlaza.

Kweli candelo, siza kuphonononga amacandelo aphambili omjikelo weseli kunye nolawulo lwawo.⁢ Umjikelo weseli Iqukethe izigaba ezininzi, phakathi kwazo isigaba se-G1 (i-Gap 1), isigaba se-S (i-DNA synthesis), isigaba se-G2 (i-Gap 2) kunye ne-M (mitosis). Ngasinye kwezi zigaba zilawulwa luluhlu lweeprotheyini kunye neempawu ze-biochemical eziqinisekisa ukuhlukana kweeseli ezichanekileyo kunye nocwangco.

Enye yezona nkqubo zibalulekileyo kwibhayoloji yemolekyuli yomjikelo weseli kukulawulwa kweendawo zokujonga. ⁣Ezi ndawo zokukhangela zisebenza njengotshintsho olumisayo okanye oluvumela ⁢ukuqhubela phambili komjikelo weseli ngokuxhomekeke kwimfezeko ye-DNA kunye nezinye izinto eziphambili. Ukusebenza kwayo okuchanekileyo kubalulekile ukukhusela ukwanda kweeseli ezinomonakalo wezofuzo kwaye, ngoko ke, ukugcina ingqibelelo yezinto eziphilayo Siza kufunda ngokucacileyo ukuba ezi zibonakaliso zifunyenwe kwaye zicutshungulwe njani yiseli ukuze kuqinisekiswe umjikelezo weseli ofanelekileyo.

2. Izixhobo zomjikelo weseli kunye nemisebenzi yazo ephambili

Umjikelo weseli yinkqubo elawulwa kakhulu eyenzeka kwiiseli ukuqinisekisa ukukhula nokuhlukana kwazo okuchanekileyo. Ngexesha lale nkqubo, izigaba ezahlukeneyo ziyenziwa kwaye amacandelo ahlukeneyo asebenze lo mdlalo imisebenzi ephambili kuphindaphindo oluchanekileyo lwemathiriyeli yemfuza kunye nokwahlulwa ngokulinganayo kweechromosomes. Apha ngezantsi ngamanye amacandelo asisiseko kumjikelo weseli kunye nemisebenzi yawo:

  • Cyclin-dependent kinases (CDKs): Ezi proteni zingundoqo ekulawuleni umjikelo weseli, ekubeni zinoxanduva lokulawula izigaba ezahlukeneyo zenkqubo. Ii-CDK zenziwa zisebenze ngokuzibophelela kwii-cyclins, iiproteni ezinamaqondo aguquguqukayo kuwo wonke umjikelo weeseli. Ngokudibeneyo, ii-CDK kunye nee-cyclins zisebenza njengotshintsho lwemolekyuli ebangela ukuqhubela phambili komjikelo weeseli.
  • Amanqaku okulawula umjikelo weseli: Ziindlela zokugada ezifumaneka kumjikelo wonke weeseli kwaye zinceda ukuqinisekisa ukuphunyezwa kwayo okuchanekileyo. La manqaku olawulo asebenza njengezivamvo kwaye abone umonakalo onokwenzeka okanye iimpazamo kwimathiriyeli yemfuza okanye koomatshini beselula.
  • Cyclosome/APC:⁣ Le proteni complex idlala indima ebalulekileyo ekuthotyweni kweecyclins kunye notshintsho phakathi kwezigaba ezahlukeneyo zomjikelo weseli. I-cyclosome / APC iqondisa ukutshatyalaliswa kwee-cyclins kunye nezinye iiprotheni ezilawulayo ngokusebenzisa inkqubo ye-ubiquitination, evumela ukuqhubela phambili umjikelezo kunye nokuqinisekisa ukulandelelana kwayo kwexesha elichanekileyo.

Ezi⁤ zezinye zezona nxalenye zenkqubo yomjikelo weseli. Ngamnye wabo udlala indima ephambili ekulawuleni nasekulungelelaniseni amanqanaba ahlukeneyo omjikelezo, ngaloo ndlela eqinisekisa ukuba iiseli ziphindaphinda kwaye zahlule ngokufanelekileyo. Uphononongo oluneenkcukacha lwala macandelo lubalulekile ukuqonda iziseko zemolekyuli zomjikelo weseli kunye nobudlelwane bayo nezifo ezinjengomhlaza.

3. Ukulawulwa komjikelo weeseli: iimbono ezivela kwibhayoloji yemolekyuli

1. Ukubaluleka kokulawulwa komjikelo weeseli

Ulawulo lomjikelo weeseli lusisiseko ekuqinisekiseni ukuba iiseli zahlulahlula ngokuchanekileyo kwaye zigcina ulungelelwano phakathi kokwanda kunye nokwanda. ukufa kweeseli. Le nkqubo ilawulwa ngokungqongqo ngoluhlu lweendlela ze-molecular ezisebenza kwizigaba ezahlukeneyo zomjikelezo, ezifana nokuphindaphinda kwe-DNA, ukuhlukana kwe-chromosome kunye nokwahlukana kweeseli.

2. Iiprotheyini eziphambili kulawulo lomjikelo weseli

Kwibhayoloji yemolekyuli, kuye kwachongwa iiproteni ezininzi ezidlala indima ebalulekileyo ekulawuleni umjikelo weeseli. Phakathi kwazo kukho i-cyclin-dependent kinases (CDKs) kunye neecyclins, ezenza ⁤icomplexes⁢ evula okanye inqanda izehlo ezahlukeneyo zomjikelo ⁤seseli. Elinye iqela leeprotheyini ezibalulekileyo ziyi-inhibitors ye-cell cycle progression, njengentsapho yeeprotheyini ze-checkpoint, ezibeka iliso kwingqibelelo ye-DNA kunye nokuthintela ukuqhubela phambili komjikelezo xa kwenzeka umonakalo wemfuza.

3. Utshintsho kulawulo lomjikelo weeseli kunye nezifo

Utshintsho kulawulo lomjikelo weseli lunokuba neziphumo ezibi emzimbeni. Ngokomzekelo, ukuchithwa kweeprotheyini ezilawula ukwanda kweeseli kunokukhokelela ekuphuhlisweni kwezifo ezifana nomhlaza, apho iiseli zihlukana ngokungalawulekiyo Ngokufanayo, iziphene kwiindlela zokulungisa i-DNA zingakhokelela kwizifo zemfuza okanye zikhokelela ekuqokeleleni ukuguqulwa kofuzo olunegalelo. ukubonakala kwezifo.

4. Ulawulo lokuphindaphinda umjikelo weseli: iindlela zokucupha

Enye yezona zinto zibalulekileyo kulawulo lomjikelo weseli kulawulo lokuphindaphinda kwayo. Ukuqinisekisa ukuba iiseli zahlula kakuhle kwaye akukho ziphazamiso ezenzekayo, iindlela zokucupha ziye zisebenze ezivavanya inkqubela echanekileyo yenqanaba ngalinye lomjikelo. Ezi ndlela zisebenza njengabagcini-masango, ziqinisekisa ukuba inkqubo yokwahlula iiseli iqhutywa ngokuchanekileyo kwaye ngaphandle kweempazamo.

Kukho ⁤indlela ezininzi zokugada ezilawula⁤ ukuphinda-phinda umjikelo weseli. Ezi ⁢iinkqubo⁢ ziyilelwe ukubona naluphi na utshintsho kwi-DNA, ⁤iimpazamo kuphindaphindo lwemathiriyeli yemfuza okanye umonakalo kwiichromosome. Enye yazo yinto ebizwa ngokuba yi-checkpoint kwisigaba se-G1, apho ihlolwe ukuba i-DNA yonakaliswe ngaphambi kokuba iseli ingene kwisigaba sokuphindaphinda. Ukuba kukho nawuphi na umonakalo ofunyenweyo, iindlela zokulungisa ziyasebenza okanye, kwiimeko ezinzima, ukufa kweeseli ezicwangcisiweyo (i-apoptosis) kubangelwa ukuthintela ukwanda kweeseli ezingaqhelekanga.

Enye indlela yokulawula yindawo yokukhangela kwisigaba se-G2, esibeka esweni ukuba i-DNA iye yaphindwa ngokuchanekileyo kwaye akukho zinguqu kubume beechromosomes. Ukuba kukho nasiphi na isiphazamiso esichongiweyo, umjikelo weseli uyanqunyanyiswa okwexeshana ukuvumela iimpazamo ukuba zilungiswe. Iprotheyini ye-p53 idlala indima ebalulekileyo kwezi ndawo zokukhangela, njengoko ilawula ukubonakaliswa kofuzo oluninzi olubandakanyekayo ekulungisweni kwe-DNA kunye ne-apoptosis.

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5. Indima yee-checkpoints ze-cell cycle ekuthinteleni umonakalo wemfuza

Iindawo zokuhlola umjikelo weseli zidlala indima ebalulekileyo ekuthinteleni umonakalo wemfuza. Ezi ndlela zokulawula zijongene nokufumanisa kunye nokulungisa iimpazamo ngexesha lokuphindaphinda kwe-DNA kunye nenkqubo yokwahlula, ukuthintela ukuqokelelwa kweenguqu kunye nokugcina ukuzinza kwe-genome.

Kukho iindawo zokuhlola ezininzi kulo lonke umjikelezo weeseli ezisebenza njengeendawo zokulawula ukunyaniseka kwe-DNA Eyokuqala kwezi ndawo zokuhlola kwinguqu ye-G1 / S, apho kuqinisekiswa ukuba i-DNA iye yafumana umonakalo kwaye ifanelekile ukuphindaphinda. . Ukuba umonakalo ufunyenwe, umjikelo weseli uyayeka kwaye iindlela zokulungisa iDNA ziyasebenza. Enye indawo ephambili yokukhangela i-checkpoint kwinguqu ye-G2 / M, eqinisekisa ukuba i-DNA iphindwe ngokuchanekileyo kwaye iqinisekisa ukunyaniseka kweechromosomes ngaphambi kokwahlula.

Ukongeza ekuboneni umonakalo wemfuza, iindawo zokuhlola nazo zinendima ebalulekileyo kwimpendulo yeselula kwiimeko zoxinzelelo kunye nomonakalo. Ngokomzekelo, phambi komonakalo we-DNA, iindawo zokuhlola zivula iindlela zokubonisa ezenza ukuba kubanjwe umjikelo weseli kunye nokusebenza kweendlela zokulungisa ukuba umonakalo awunakulungiswa, i-apoptosis inokuqaliswa, inkqubo ecwangcisiweyo yokufa kweeseli ukuthintela ukwanda kweeseli ezonakalisiweyo.

6. Indima ye-tumor suppressor genes kulawulo lomjikelo weseli

Iijini ze-tumor suppressor zidlala indima ebalulekileyo ekulawuleni umjikelo weseli, ukugcina ulungelelwaniso oluchanekileyo phakathi kokwanda kweeseli kunye nokucinezelwa kokwakheka kwethumba. Ezi khowudi zofuzo kwiiprotheni ezisebenza njengeziqhoboshi kwinkqubo yokwahlukana kweeseli, ukuthintela ukuphindaphinda kwe-DNA engalawulwayo kunye nokubonakala kweeseli zomhlaza. Ngezantsi kukho amanqaku aphambili ngayo:

  • Indawo yothintelo lolawulo: Iijini ezicinezela ithumba zidlala indima ebalulekileyo ekulawuleni indawo yothintelo lomjikelo weseli.⁤ Esi sigaba simisela ukuba iseli iyazibophelela na ekwahluleni okanye ingene kwimo yokunqumama eyaziwa njengesigaba se-G0. Iiprotheyini ezifana ne-p53, enye yezona zinto zifundwayo ze-tumor suppressor genes, zifumanisa kwaye zilungise i-DNA eyonakalisiweyo ngaphambi kokuvumela ukungena kwisigaba se-S Ukuba ukulungiswa akunakwenzeka, i-p53 ibangela i-apoptosis, ngaloo ndlela ikhusela ukwanda kweeseli ezinokuguqulwa kofuzo eziyingozi.
  • Ummiselo wenguqu ye-G1/S: Ngexesha lokutshintsha phakathi kwezigaba ze-G1 kunye ne-S, isigqibo esibalulekileyo senzeke malunga nokuba iseli iyaqhubeka nomjikelezo weseli okanye iphuma kumjikelo kwaye ingene kwimeko epholileyo. Iijeni ze-tumor suppressor zibandakanyeka kwimimiselo ephambili yolu tshintsho, njengokuthintela i-cyclin-dependent kinase 4 (CDK4), elawula ukuqhubela phambili komjikelo weseli. Ngaphezu koko, iiprotheni ezifana nezo ze-retinoblastoma complex (Rb) zinqanda utshintsho lwe-G1 / S de kube iimeko ezifanelekileyo zokuphindaphinda kwe-DNA zidibene.
  • Ukuthintela i-angiogenesis ye-tumor: Ukongeza kwindima yabo ekulawuleni umjikelo weseli, i-tumor suppressor gene nayo ibandakanyeka ekuthinteleni ukwakheka kwemithambo yegazi engaqhelekanga, eyaziwa ngokuba yi-tumor angiogenesis. Ezi proteni zicinezela ukuveliswa kwemiba yokukhula kwemithambo ekhuthaza ukukhula kwemithambo yegazi emitsha kwizicubu zethumba. Ngokwenza njalo, banciphisa ukunikezelwa kwezondlo kunye neoksijini kwiithumba, okwenza ukukhula kunye nokuphila kwabo kube nzima.

Isishwankathelo, i-tumor suppressor genes zizinto ezibalulekileyo kulawulo lomjikelo weseli, ukulawula amanqaku aphambili njengendawo yokuthintela kunye notshintsho lwe-G1 / S. Ukongeza, badlala indima ebalulekileyo ekuthinteleni i-angiogenesis ye-tumor. Ukuqonda ukusebenza kwayo kuya kuvumela inkqubela kuphuhliso lonyango⁢ olujolise ekubuyiseleni okanye ekwandiseni umsebenzi walo, olunokubonelela ngezicwangciso ezintsha zokunyanga umhlaza.

7. Ukusebenzisana phakathi kweziganeko zebhayoloji yemolekyuli kunye nomjikelo weeseli

Kwihlabathi elinomtsalane lebhayoloji yemolekyuli, izehlo ezenzekayo ngexesha lomjikelo weseli zinxulunyaniswa ngokwangaphakathi kunxibelelwano phakathi kweemolekyuli ezahlukeneyo kunye neenkqubo zebhayoloji. Olu nxibelelwano ludlala indima ebalulekileyo kulawulo nakulawulo lwesigaba ngasinye somjikelo weeseli, ukusuka kukuphindwaphindwa kweDNA ukuya kulwahlulo lwechromosome kulwahlulo lweeseli. Ngezantsi, siza kuphonononga ezinye zentsebenziswano eziphambili ezenzeka kule nkqubo intsonkothileyo nelungelelaniswe kakhulu.

1. Phosphorylation kunye ne-dephosphorylation⁢ yeeprotheyini: Ngethuba lomjikelezo weseli, iiprotheni eziphambili ezilawula ukuqhubela phambili komjikelezo okanye ukubanjwa zilawulwa ngokongezwa okanye ukususwa kwamaqela e-phosphate. Olu hlengahlengiso lunokuchaphazela umsebenzi walo, indawo yokuhlala kunye nokusebenzisana kwayo nezinye iiprotheni, ezichaphazela ngokuthe ngqo iziganeko zemijikelezo yeeseli.

2. Ukudibana kwe-DNA-protein: Iiprotheyini ezithile zibophelela kwi-DNA ukulawula iinkqubo ezifana nokuphindaphinda, ukukhutshelwa, kunye nokulungiswa kwezinto zofuzo. ⁢Olu nxibelelwano lumisela ukuba yeyiphi imimandla ye-DNA eza kukhutshelwa ⁤okanye iphindwe isigaba ngasinye somjikelo weseli, ngaloo ndlela kuqinisekisa ukuphindaphindwa okuchanekileyo kunye nokulungiswa kwegenome.

3. Iibhayisekile kunye ne-cyclin-dependent kinases: Ii-Cyclins ziiprotheyini eziqokelela ngamaxesha ahlukeneyo kumjikelo weseli kwaye zibophe kwi-enzymes ezibizwa ngokuba yi-cyclin-dependent kinases. Olu nxibelelwano luyinkimbinkimbi lulawula umsebenzi we-kinases, leyo i-phosphorylate ezinye iiprotheni eziphambili ekuqhubekeni komjikelo weseli. Ummiselo ochanekileyo wolu nxibelelwano lubalulekile ukuqinisekisa ukuqhubela phambili okwaneleyo kunye nocwangco kumjikelo weseli.

8. Ukubaluleka kozinzo lwe-genome ngexesha lomjikelo weseli

Uzinzo lwe-genome ngexesha lomjikelo weseli luphawu olusisiseko lokuqinisekisa ukusebenza okuchanekileyo kweeseli I-genome, equkethe lonke ulwazi lwemfuza yento ephilayo, kufuneka igcinwe ingaguquki kwaye ngaphandle kotshintsho ukuze iinkqubo zeselula ziphuhlise ngokufanelekileyo. Oku kuthetha ukuba ⁢iikhromozomi ziphindaphindwa kwaye zisasazwe ngokuchanekileyo ngexesha lokwahlulahlulwa kweeseli, kuthintelwa iimpazamo ezinokukhokelela ⁢kubume besifo.

Enye yezona nkalo zibalulekileyo zokuzinza kwe-genome kukukwazi ukulungiswa kwe-DNA. Kuwo wonke umjikelo weseli, kokubini ukuphindaphindwa kwe-DNA kunye nomonakalo wemfuza unokwenzeka. Nangona kunjalo, indlela yokulungisa i-DNA isebenza njengenkqubo yokucupha echonga kwaye ilungise utshintsho olukhoyo kwi-genome. ⁢Oku kuthintela ukwanda kweemposiso kwaye kugcine imfezeko yolwazi lwemfuzo.

Ukongeza kulungiso lwe-DNA, omnye umba obalulekileyo wozinzo lwe-genome kukulawulwa komjikelo weseli. Ngexesha ngalinye lesigaba somjikelo weseli, uthotho lweziganeko lwenzeka eziqinisekisa ukuphinda-phinda okuchanekileyo kunye nokwahlulwa kweechromosomes. Izinto ezilawulayo, ezifana ne-cyclin-dependent protein kinases, ukulawula ukuqhubela phambili komjikelo weseli kunye nokuqinisekisa ukuba isigaba ngasinye sigqityiwe ngaphambi kokuqhubela phambili ukuya kwesinye. Ngale ndlela, ukuvela kwe-chromosomal abnormalities kuyaphetshwa kwaye kuyaqinisekiswa ukuba iiseli zeentombi zizuza ikopi ethembekileyo yegenome yabazali.

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9. Izixhobo zemolekyuli kunye nobuchule bokufunda umjikelo weseli

Inkqubela kubugcisa beemolekyuli kwiminyaka yakutshanje iye yaluguqula uhlolisiso lomjikelo weeseli. Izixhobo kunye nobuchule bemolekyuli zinika ingcaciso eneenkcukacha kwiindlela ezisisiseko ezilawula umjikelo weeseli, phantsi kweemeko eziqhelekileyo kunye neemeko zokugula.

Esinye sezixhobo ezisetyenziswa kakhulu kuphando lomjikelo weseli yi-flow cytometry. Obu buchule buvumela ukuba silinganise kwaye sihlalutye isixa se-DNA kwiiseli, esinika ulwazi malunga nesigaba somjikelo weseli apho iseli nganye ikhoyo. Ukongeza, i-flow cytometry ikwasetyenziselwa ukuchonga nokwahlula iintlobo ezahlukeneyo zeeseli kubemi, okwenza kube lula ukufunda iimpawu kunye nemisebenzi yazo.

Esinye isixhobo esibalulekileyo ziinkqubo zePCR (Polymerase Chain Reaction). I-PCR ikuvumela ukuba ukhulise ngokukodwa kwaye ubhaqe i-DNA okanye i-RNA ulandelelwano lomdla kwisampulu yebhayoloji. Oku kusivumela ukuba sichonge ubukho bezakhi zofuzo ezinxulumene nomjikelo weseli kwaye sivavanye intetho yabo kwizigaba ezahlukeneyo zomjikelezo. Ukongezelela, i-PCR ingasetyenziselwa ukuhlalutya ukuguqulwa kwemfuza okunokuthi kubandakanyeke kulawulo lomjikelo weeseli.

10. Usetyenziso oluphezulu lwebhayoloji yemolekyuli kuphando lomjikelo weeseli

Kwinkalo yophando lomjikelo weeseli, usetyenziso oluphambili lwebhayoloji yemolekyuli iguqule indlela esiziqonda ngayo iinkqubo zeselula. Ngezantsi sibonisa ezinye zezicelo eziphawuleka kakhulu:

1. Next Generation Sequencing (NGS): Itekhnoloji ye-NGS yenze ukuba kwenzeke ukulandelelana ⁢izixa ezikhulu ze-DNA kunye ne-RNA ngokuchaneka okuphezulu kunye nesantya. Oku kuye kwaba luncedo kuphando lweeseli zeeseli, njengoko kusinike imbono ebanzi yokubunjwa kunye nokulandelelana kwe-nucleic acids echaphazelekayo kumgaqo womjikelezo. Ukongeza, i-NGS iququzelele ukuchongwa kwezinto ezintsha ezahlukeneyo zofuzo ezinxulumene nokuphazamiseka komjikelo weseli.

2. Ukuhlelwa kweGene nge-CRISPR-Cas9: Ubuchule bokuhlela i-CRISPR-Cas9 gene bube luncedo ngakumbi kuphando lomjikelo weseli. Ngesi sixhobo, izazinzulu ziyakwazi ukuguqula ngokuchanekileyo nangokufanelekileyo izakhi zofuzo kwiiseli, ezisivumela ukuba sihlolisise umphumo wolu tshintsho kumjikelo weseli. Oku kukhokelele ekufunyanisweni okubalulekileyo malunga ⁣ neendima zejini ezahlukeneyo kulawulo lomjikelo⁢ kwaye kuqhubele phambili uphuhliso⁢ zonyango lwemfuza olujolise kwizifo⁢ ezinxulumene notshintsho kule nkqubo.

3. Super-resolution fluorescence microscopy: I-Super-resolution fluorescence microscopy isinike imbono entsha kwiziganeko zeselula ngexesha lomjikelo. Obu buchwephesha buvumela ukuba sifumane imifanekiso enesisombululo esiphezulu ngokumangalisayo, ebonisa iinkcukacha ezingaphantsi kweeseli ezingabonakaliyo ngaphambili. Oku kusivumele ukuba sichonge izakhiwo ezitsha ezinxulumene nenkqubo yomjikelezo weeseli, ezifana ne-microtubules kunye ne-protein complexes, kunye nokuqonda kangcono ukuguquguquka kwezi ziganeko kwinqanaba le-molecular.

11. Iimpembelelo zeklinikhi zenkqubela phambili kwibhayoloji yemolekyuli yomjikelo weeseli

Inkqubela phambili kwibhayoloji yemolekyuli yomjikelo weeseli kunye nefuthe layo leklinikhi

Inkqubela phambili kwicandelo lebhayoloji yemolekyuli iguqule ukuqonda kwethu umjikelo weeseli kunye neziphumo zayo zeklinikhi. Ezi nkqubela phambili zenze ukuba kube lula ukuchonga iithagethi ezintsha zonyango zonyango lwezifo ezinxulumene nokunyuka kweeseli ezingaqhelekanga, ezifana nomhlaza. Ngophononongo olucacileyo lweendlela zokubonisa kunye neendlela zemolekyuli ezilawula umjikelo weeseli, abaphandi baye bakwazi ukuphuhlisa izicwangciso ezisebenzayo kunye nezomntu ngamnye.

Esinye seziphumo ezibalulekileyo kukuchongwa kweenguqu zofuzo ezinegalelo ekuphuhliseni izifo ezikhulayo kunye nokusetyenziswa kwazo njengeempawu zebhayoloji zokuxilongwa kunye nokuxilongwa kwezifo. Ukufunyaniswa kotshintsho kwimizila yemfuza ephambili ebandakanyekayo kumjikelo weseli, njengeejini ze-tumor suppressor kunye ne-oncogenes, kwenze ukuba kube lula ukuchonga amaqela amancinci ezigulana ezinomngcipheko ophezulu wokuphinda okanye impendulo engcono kunyango oluthile.

Omnye umba obalulekileyo kuphuhliso lonyango ekujoliswe kulo oluthatha ithuba lobuthathaka obuthile bemolekyuli yeeseli zethumba. Olu nyango, olufana ne-kinase inhibitors okanye amachiza avala ukuphindaphinda kwe-DNA,⁤ abonakaliswe ukuba asebenza kakhulu kwiintlobo ezithile zomhlaza. Ngokuqonda ngcono i-biology ye-molecular of the cell cycle, oogqirha banokukhetha unyango olufanelekileyo kwisigulane ngasinye, ukwandisa ukusebenza kunye nokunciphisa imiphumo emibi.

  • Ukuqhubela phambili kwi-biology ye-molecular kuchonge iithagethi ezintsha zonyango kunyango lomhlaza kunye nezinye izifo ezikhulayo.
  • Iinguqu zemfuzo ezichongiweyo kwiijini eziphambili zomjikelo weseli zisetyenziswa njengeempawu zebhayoloji zoxilongo kunye noxilongo lwezifo.
  • Ulwazi malunga nebhayoloji yemolekyuli yomjikelo weeseli ivumela ukuphuhliswa konyango olusebenzayo ngakumbi kunye nolomntu ngamnye.

12. Iimbono zexesha elizayo kuphando kwibhayoloji yemolekyuli yomjikelo weeseli

1. Ukuqhubela phambili kulandelelwano lwe-DNA: Itekhnoloji yolandelelwano lwesizukulwana esilandelayo iguqule icandelo lokufunda ngebhayoloji ye-cell cycle molecular. Ngokukwazi ukulandelelana ngokukhawuleza inani elikhulu le-DNA, izazinzulu zinokwenza uhlalutyo olukhulu lwe-genomic, zichonge iinguqu, kwaye ziqonde ngcono ubudlelwane phakathi kofuzo kunye nomjikelo weseli. Kwixesha elizayo, ulandelelwano lwe-DNA kulindeleke ukuba luqhubeke nokuguquka, ukuphucula ukuchaneka kunye nokunciphisa iindleko, ukuvumela ukuba imibuzo enzima ngakumbi iqwalaselwe kunye nolwazi oluthe kratya malunga nokulawulwa komjikelo weseli ukuba kufunyanwe.

2. Ubuchule bokuchwetheza bemakroskopu: I-Microscopy sisixhobo esibalulekileyo kuphando lwebhayoloji yemolekyuli yomjikelo weeseli. Ukuphuhliswa kweendlela eziphambili zemicroscope, ezifana ne-super-resolution microscopy kunye ne-three-dimensional fluorescence microscopy, ivumele izazinzulu ukuba zibe nombono ochaneke ngakumbi weenkqubo zemolekyuli ngaphakathi kweeseli. Kwixesha elizayo, kulindeleke ukuba ezi zixhobo ziya kuqhubeka ziphucuka, zibonelela ngesisombululo esikhulu ngakumbi kunye nokukwazi ukujonga iinkqubo. ngexesha langempela. Oku kuya kuvumela ukuqonda ngakumbi ukuba iziganeko eziphambili zomjikelezo weseli zilawulwa njani kunye nendlela iimolekyuli ezahlukeneyo ezisebenzisana ngayo kule nkqubo.

3. Imodeli yokulinganisa kunye nokulinganisa: Ngokukhula okubonakalayo kwinani leedatha kunye nolwazi oluqokelelwe malunga nomjikelezo weseli, imfuno yokuhlalutya kunye nezixhobo zemodeli iya ibaluleke kakhulu. Kwixesha elizayo, umfuziselo wokubala kunye nokulinganisa kulindeleke ukuba kudlale indima ebaluleke nangakumbi kuphando lwebhayoloji yomjikelo weeseli. Oku kuya kuvumela izazinzulu hlalutya idatha ngendlela edibeneyo, qikelela intsebenziswano yeemolekyuli kunye nokuziphatha,⁤ kunye nokuvavanya i-hypotheses ngokufanelekileyo. Imodeli yokubala iya kunceda ukuveza unxibelelwano olufihliweyo kumjikelo weseli kunye nokuvelisa iindlela ezintsha zophando kunye nophuhliso lonyango oluchasene nezifo ezinxulumene nokungasebenzi kakuhle kweselula.

13. Iingcebiso zokufunda kunye nokuqonda i-biology ye-molecular of the cell cycle

Ibhayoloji yemolekyuli yomjikelo weseli sisihloko esinomdla nesinzima esifuna uphononongo olungqongqo kunye nokuqonda okunzulu ukuphonononga ukusebenzisana okuntsonkothileyo okulawula ukukhula kunye nophuhliso lweeseli. Apha ngezantsi kukho iingcebiso eziphambili ezinokukunceda uphengulule kweli candelo kwaye wandise ulwazi lwakho:

  • Yakha isiseko esiluqilima: Phambi kokuphonononga kwibhayoloji yemolekyuli yomjikelo weeseli, kubalulekile ukuba ube nokuqonda kakuhle kwebhayoloji yeeseli kunye neengqikelelo ezisisiseko zemfuzo. Ziqhelanise namacandelo eselula abandakanyekayo kumjikelo weseli, njengeprotein kinases kunye nezinto zokukhula.
  • Phanda iindlela zovavanyo: Ukuqonda i⁢ yebhayoloji yemolekyuli yomjikelo weseli, kubalulekile ukuba nolwazi⁤ malunga nobuchule obusetyenziswa kwilabhoratri. Funda malunga ne-massspectroscopy, i-fluorescence microscopy, i-PCR kunye nezinye iindlela ezivumela uphononongo oluneenkcukacha zoomatshini bemolekyuli ababandakanyekayo kulawulo lomjikelo weeseli.
  • Phonononga uncwadi lwenzululwazi: Ukuphonononga ⁤uncwadi⁤ lwezenzululwazi kubalulekile ukuhlala usazi ngenkqubela phambili kunye nezinto ezifunyaniswe kwinkalo yebhayoloji yemolekyuli yomjikelo weseli. Funda amanqaku awodwa, jonga kwakhona olona papasho lufanelekileyo ⁤kwaye uziqhelanise namagama obugcisa⁢ asetyenziswa kwindawo.
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Isishwankathelo, uphononongo kunye nokuqonda kwebhayoloji yemolekyuli yomjikelo weeseli kufuna isiseko esiluqilima kwibhayoloji yeeseli kunye nemfuza, kunye nolwazi olusebenzayo lweendlela zovavanyo ezisetyenzisiweyo. Ukongeza, kubalulekile ukuhlala usexesheni⁢ ngokuphonononga uncwadi lwenzululwazi. Ngezi ngcebiso, uya kuba kwindlela elungileyo yokukhangela kwiimfihlakalo zolawulo lomjikelo weeseli kwaye ube negalelo ekuqhubeleni phambili kophando kule ndawo inomdla yokufunda.

14. Izigqibo kunye neengqwalasela zokugqibela malunga nendima yebhayoloji yemolekyuli kumjikelo weeseli

Ukuqukumbela, ibhayoloji yemolekyuli idlala indima ebalulekileyo kumjikelo weeseli, isivumela ukuba siqonde kwaye sifunde iindlela ezilawula inqanaba ngalinye lomjikelo. Ngombulelo kwiindlela zebhayoloji ye-molekyuli, kuye kwenzeka ukuchonga kunye nokubonakalisa iiprotheni eziphambili ezibandakanyekayo ekuphindaphindeni kwe-DNA, ukwahlula i-chromosome, kunye nokulawulwa komjikelo weeseli.

Ngokuhlalutya umsebenzi weeproteni kunye nofuzo ukuba thatha inxaxheba kumjikelo weseli, kuye kwafunyaniswa ukuba naluphi na ukuguqulwa komsebenzi walo kunokukhokelela kwizifo ezifana nomhlaza Ukongeza, i-biology ye-molecular iye yavumela ukuphuhliswa kweendlela zonyango ezijoliswe kuzo, ezithatha inzuzo yolwazi malunga neenkqubo ze-molecular zomjikelezo weseli ukuyila iziyobisi eziphazamisayo. kunye neendlela zokwanda kweeseli zethumba.

Ubuchwephesha bebhayoloji yemolekyuli bukwaququzelela ufundo lolawulo lomjikelo weeseli kwizinto ezahlukeneyo eziphilayo, ezithe zatyhila iindlela eziqhelekileyo kunye nomahluko othile phakathi kweentlobo. Ezi ziphumo zibe negalelo ekuqhubeleni phambili kwesayensi kwaye zibonelele ngemibono emitsha yokuqonda izifo ezinxulumene nokungasebenzi kakuhle kumjikelo weseli. indlela yenkqubela phambili yexesha elizayo kwicandelo lamayeza kunye nonyango lwemfuza.

Imibuzo neempendulo

Umbuzo: Yintoni ibhayoloji yemolekyuli yomjikelo weeseli?
Impendulo: Imolekyuli yebhayoloji yomjikelo weeseli lufundo lweenkqubo zemolekyuli ezilawula ukuphindaphinda kweeseli, ukukhula nokwahlukana. Ijolise ekuqondeni iindlela ezisisiseko zokulawulwa komjikelo weseli, kubandakanywa ukuphindaphindwa kwe-DNA, ukubhalwa kofuzo, kunye nokuguqulelwa kweprotheyini.

Umbuzo: Kutheni kubalulekile ukufunda umjikelo weeseli?
Impendulo: Uphononongo lomjikelo weseli lubalulekile ukuqonda iinkqubo zebhayoloji ezisisiseko ezenzeka kwiiseli. Inika ulwazi oluyimfuneko malunga nokukhula kunye nokuphuhliswa kwezinto eziphilayo, kunye nokulawulwa kokwanda kweeseli. ⁤Ukwengeza, ulwazi⁢ lomjikelo weseli lubalulekile ⁣ukuqonda kunye nokunyanga izifo ezinjengomhlaza, apho ⁢ukuyekwa kommiselo kwenzeka kulwahlulo lweeseli.

Umbuzo: Bubuphi ubuchule obusetyenziswayo kwibhayoloji yemolekyuli yomjikelo weeseli?
Impendulo: Iintlobo ezahlukeneyo zeendlela eziphambili zisetyenziselwa i-cell cycle biology ye-molecular, kubandakanywa ukuhamba kwe-cytometry, ukulandelelana kwe-DNA, i-microscopy ye-confocal, kunye nokuguqulwa kofuzo. iziganeko ezahlukeneyo ezenzeka ngexesha lezigaba zomjikelo weseli.

Umbuzo: Yintoni⁤⁢ i⁤ amanqanaba omjikelo weseli?
Impendulo: Umjikelezo weseli uqukethe ezine eziphambili ⁢inqanaba: isigaba se-G1 (i-pre-synthesis), isigaba se-S (i-DNA synthesis), isigaba se-G2 (i-pre-mitosis) kunye nesigaba se-M ⁤(mitosis) . Ngethuba lesigaba se-G1, iseli iyakhula kwaye ilungiselele ukuphindaphinda kwe-DNA. Kwinqanaba le-S, i-DNA entsha iyadityaniswa. Emva koko, kwisigaba se-G2, iseli ilungiselela ulwahlulo kwaye ekugqibeleni, kwinqanaba le-M, ukwahlukana kweeseli kwenzeka nge-mitosis.

Umbuzo: Ngabaphi abalawuli abaphambili bomjikelo weseli?
Impendulo: Abalawuli abaphambili bomjikelezo weseli yi-cyclin-dependent protein kinases (CDKs) kunye ne-cyclins. Ezi proteni zenza ii-complexes ezilawula ukuqhubela phambili komjikelo weeseli, ziqinisekisa ukuba isigaba ngasinye sigqityiwe ngaphambi kokuba sidlulele kwelinye. Umsebenzi we-CDKs kunye nee-cyclins zilawulwa ngokufanelekileyo ngezibonakaliso ze-intracellular kunye nobukho bezinto zokukhula zangaphandle.

Umbuzo: Ibhayoloji yemolekyuli yomjikelo weseli inxulumene njani nomhlaza?
Impendulo: Kumhlaza, utshintsho lwenzeka kwiindlela zokulawula umjikelo weeseli, ezikhokelela ekuhlukaneni kweeseli ezingalawulekiyo kunye nokubunjwa kwamathumba. Uphononongo lwebhayoloji yemolekyuli yomjikelo weeseli luveze ukungahambi kakuhle kofuzo kunye ne-epigenetic ezinxulumene nophuhliso lomhlaza. Ukuqonda ezi nkqubo kubalulekile⁤ kuyilo lonyango ekujoliswe kulo nakuphuhliso lonyango olusebenzayo ngokuchasene ⁣ nomhlaza.

Umbuzo: Unokuzifumana phi iinkcukacha ezingakumbi ngebhayoloji yemolekyuli yomjikelo weeseli?
Impendulo: Kukho intaphane yeencwadi, iijenali zenzululwazi, kunye nemithombo ye-intanethi enika iinkcukacha ezineenkcukacha ngebhayoloji yemolekyuli yomjikelo weeseli. Eminye imithombo ecetyiswayo ibandakanya Alberts 'Molecular Biology of the Cell, Nature Reviews Molecular Cell Biology, kunye iidathabheyisi njengePubMed. Ukongeza, iiyunivesithi ezininzi kunye namaziko ophando abonelela ngezifundo kunye neenkqubo zokufunda ezinikezelwe kwibhayoloji yemolekyuli yomjikelo weseli.

Ukuququmbela

Ukuqukumbela, uphononongo lwe-Molecular Biology ye-Cell Cycle lubalulekile ekuqondeni iinkqubo zokwahlulwahlulwa kweeseli kunye nolawulo lwayo. Ngokuhlalutya iindlela zeemolekyuli ezibandakanyekayo kule nkqubo, abaphandi baye bakwazi ukuqhubela phambili ulwazi lwezifo ezinxulumene nokuguqulwa komjikelo weseli, njengomhlaza. Izinto ezifunyenweyo kunye nenkqubela phambili kulo mmandla zivule amathuba amatsha onyango kunye nokuxilongwa, kwaye zibeke iziseko zophuhliso lonyango olusebenzayo kunye nolomntu ngamnye. Eli nqaku libonelele ngombono weengcamango eziphambili kunye neziphumo kwi-Molecular Biology ye-Cell Cycle, ngokubonisa umjikelo weseli njengenkqubo elawulwa kakhulu kwaye ilawulwa kwinqanaba le-molecular. Kulindeleke ukuba olu lwazi luqhubeke lukhula kwiminyaka ezayo, lubonelela ngemibono emitsha kunye nezisombululo kwimingeni ekhoyo kwibhayoloji nakwiyeza. .

Molecular Biology Cell Cycle PDF

Uhlaziyo lokugqibela: 29/08/2023
Umbhali: USebastian Vidal

Imolekyuli yebhayoloji yomjikelo weeseli yinkalo ebalulekileyo yophando kuphando lwenzululwazi, kuba isenza siqonde nzulu iinkqubo ezilawula umjikelo wobomi beeseli. Kweli nqaku, siza kuphonononga ifuthe lebhayoloji yeemolekyuli ekuqondeni kwethu umjikelo weeseli, sigxile kwezona nkqubela zifanelekileyo kunye nokufumanisayo. ⁢Ngophononongo olubanzi loncwadi lwenzululwazi, siyakuhlalutya imiba engundoqo yomjikelo weseli kunye nommiselo wayo, ngenjongo yokubonelela ngombono wehlabathi kunye nohlaziywayo kwesi sihloko sokubaluleka kwe-biochemical.

Intshayelelo kumjikelo weseli

I umjikelo weseli Yinkqubo esisiseko⁣ kubomi bazo zonke iiseli. Ebudeni bale nkqubo intsonkothileyo, iiseli zifumana uthotho lweziganeko ezicwangcisiweyo nezilawulwayo ezivumela ukuba zikhule, ziphindaphinde imathiriyeli yemfuza yazo, kwaye ekugqibeleni zahlulwe zibe ziiseli zeentombi ezimbini ezifanayo. Ngezantsi ziziganeko eziphambili ezenza umjikelo weseli:

  • Isigaba se-G1 (iGap 1): Kweli nqanaba, iseli iyakhula kwaye ilungiselele ukuphindaphinda kwe-DNA yayo. Iiprotheyini kunye ne-RNA eziyimfuneko ekuphindaphindweni kwezinto zofuzo ziyadityaniswa.
  • S iSigaba ⁣(Ulungelelwaniso): Ngexesha lesi sigaba, iseli ⁢iphinda imathiriyeli yemfuzo. I-DNA⁤ iphindaphinda ngokuchanekileyo kwaye⁢ ngokuthembekileyo, iqinisekisa ukuba iseli nganye yentombi ifumana ikopi epheleleyo kunye efanayo yeDNA yoqobo.
  • Isigaba se-G2 (I-Gap 2): Kweli nqanaba, iseli iyaqhubeka ikhula kwaye ilungiselela ukwahlukana kweeseli. Iiprotheyini ezininzi kunye ne-RNA ziyadityaniswa, eziyimfuneko ekwenziweni kwamacandelo eselula ayimfuneko kulwahlulo.

Emva kokuba umjikelezo weseli ugqityiwe, iseli inokungena kwisigaba sokwahlula, esaziwa ngokuba yi-mitosis okanye i-meiosis, kuxhomekeke kuhlobo lweseli. Ngexesha le-mitosis, iseli iyahlula kwiiseli zentombi ezimbini ezifanayo, nganye iqulethe ikopi epheleleyo yemathiriyeli yemfuzo. Ngakolunye uhlangothi, i-meiosis yinkqubo ekhethekileyo yokwahlukana kweeseli eyenzeka kwiiseli zokuzala kwaye inciphisa inani lezinto zofuzo kwiseli nganye yentombi ngesiqingatha.

Umjikelo weseli ulawulwa ngononophelo luluhlu lweeprotheyini kunye neendlela zokulawula eziqinisekisa ukunyaniseka kwezinto zofuzo kunye nokwahlulahlula kweeseli ezichanekileyo. Ukuguqulwa kulawulo lomjikelo weeseli kunokuba nemiphumo emibi, njengokuphuhliswa kwezifo, kuquka nomhlaza. Ke ngoko, ukuqonda iziganeko kunye nokulawulwa komjikelo weseli kubalulekile kuphando kunye namayeza.

Indima yebhayoloji yemolekyuli kumjikelo weeseli

Ibhayoloji yemolekyuli idlala indima ebalulekileyo kufundo nasekuqondeni umjikelo weeseli, inkqubo eyimfuneko ekukhuleni nasekuveliseni iiseli. Ngokuhlalutya iincindi zemolekyuli kunye nokusebenzisana kwazo, abaphandi banokutyhila iindlela eziphambili ezilawula inqanaba ngalinye lomjikelo weeseli.

Okokuqala, ibhayoloji yeemolekyuli isivumele ukuba sichonge kwaye sibonakalise iiproteni eziphambili ezibandakanyekayo kulawulo lomjikelo weeseli. Umzekelo, ii-cyclin kunye ne-cyclin-dependent kinases (CDKs) zizinto ezibalulekileyo zokuqhubekeka komjikelo weseli. Ngombulelo ekusebenziseni ubuchule obufana ne-gel electrophoresis kunye ne-mass spectrometry, sinokubona kwaye silinganise ezi proteni, kunye nokuhlalutya ukuguqulwa kwazo emva kokuguqulelwa.

Ukongeza, ibhayoloji yeemolekyuli ibonelele ngenkqubela ephawulekayo ekuqondweni koomatshini bemolekyuli abalawulayo umjikelo weseli. Umzekelo, enkosi kubuchule bemikroskopu ye-fluorescence, abaphandi banokuba nomfanekiso ngqondweni ngokuchanekileyo wendawo kunye nokutshintsha kweeproteni ezibandakanyekayo kuphindaphindo lwe-DNA, ulwahlulo lwechromosome, kunye nokwahlulahlulwa kweeseli. Olu lwazi lubalulekile ukuqonda ukuba ezi nkqubo zisisiseko zemfezeko yegenome zilungelelaniswa kwaye zilawulwa njani.

Iindlela zokulawula umjikelo weeseli

Ziyisethi yeenkqubo ze-intracellular ezivumela ukuba silawule kwaye silungelelanise ulwahlulo oluchanekileyo kunye nokuveliswa kweeseli. Ezi ndlela zibalulekile ukuqinisekisa ukugcinwa kwengqibelelo ye-genomic kunye nokuthintela ukuphuhliswa kwezifo ezifana nomhlaza.

Enye yezona zinto ziphambili kukulawulwa kwendawo yokuthintela i-G1-S. Ngeli xesha, iseli ivavanya iimeko zokusingqongileyo kunye neempawu zokukhula ngaphambi kokuzibophelela ekuqaliseni ukuphindaphinda kweDNA. Ukuba umonakalo we-DNA okanye iimeko ezingathandekiyo zifunyenwe, uthotho lweempawu zokubanjwa komjikelo weseli ziyasebenza ezinqanda ukuqhubela phambili ukuya kwinqanaba le-S Ukuba le miqondiso ayilungiswanga, inokubangela ukufa kweseli ecwangcisiweyo⁢, eyaziwa ngokuba yi-apoptosis.

Enye indlela ephambili yokulawula ifunyenwe kwisigaba se-S kunye ne-G2-M yokuhlola isigaba. Ezi ndawo zokuhlola zivavanya ukuphindaphinda okuchanekileyo kwe-DNA kunye nokuthembeka kwayo ngaphambi kokuba udlulele kwelinye. isigaba somjikelezo weseli. Ukuba kufunyenwe umonakalo we-DNA, iindlela zokulungisa zenziwe zisebenze ezifuna ukulungisa iimpazamo ngaphambi kokuqhubeka nokuhlukana kweeseli. Ukuba umonakalo unokulungiswa, i-apoptosis iphinda iqhutywe kwakhona ukukhusela ukwanda kweeseli ezingazinzanga.

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Ukubaluleka⁤ kwe-cyclin kunye ne-cyclin-dependent kinases

I-Cyclin yiprotheyini ephambili ebandakanyekayo kulawulo lomjikelo weeseli. ⁤Imisebenzi njenge-enzymatic regulator⁢, isebenzisana ne-cyclin-dependent kinases (CDK) ukwenza imisebenzi eyahlukeneyo kumjikelo weseli. Ilele kumandla ayo okulawula ukuqhubeka komjikelo weseli kunye nokuqinisekisa ukuphindaphinda okuchanekileyo kunye nokwahlulwa kwe-DNA.

Ii-Cyclins zibonakaliswa nge-cyclically ngexesha lokujikeleza kweeseli kwaye zilawula umsebenzi we-CDKs Ezi proteni zenza ii-complexes ezisebenzayo kunye ne-CDK, zivumela i-phosphorylation ye-substrates ethile ebandakanyekayo kwizigaba ezahlukeneyo zomjikelo we-Cyclin-dependent cycle ukulawulwa kwe-checkpoint, utshintsho ukusuka kwisigaba se-G1 ukuya kwisigaba se-S, kunye nokuhlukana kwe-chromosome ngexesha le-mitosis.

Ubukho obaneleyo bee-cyclins kunye ne-CDK buyimfuneko ekusebenzeni okuchanekileyo komjikelezo weseli Ukutshatyalaliswa kwintetho okanye umsebenzi wale proteni kunokukhokelela kwizifo ezifana nomhlaza. Ke ngoko, ukuqonda ⁢ kubalulekile kuphando kunye ⁣ nophuhliso lonyango olujoliswe kuyo olunokuthi luhlengahlengise umsebenzi walo kwaye lunyange ngokufanelekileyo izifo ezinxulumeneyo. kunye nomjikelo weseli.

Izigaba zomjikelo weseli kunye neziganeko ezinxulumene nemolekyuli

Umjikelo weseli yinkqubo entsonkothileyo equka izigaba ezahlukeneyo, ngalinye lineziganeko ezinxulumene nemolekyuli. Ezi zigaba zibalulekile ekukhuleni okuchanekileyo kunye nophuhliso lwezinto eziphilayo ezininzi. Apha ngezantsi, amanqanaba aphambili omjikelezo weseli kunye neziganeko zemolekyuli ezenzeka kuyo nganye yazo zichazwe ngokufutshane:

Isigaba⁢ G1: Ngesi sigaba, iseli ilungiselela ukwahlukana. Umsebenzi onzima we-metabolic wenziwa kwaye iiprotheyini kunye ne-RNA eziyimfuneko ekukhuleni kweeseli ziyadityaniswa. Ezinye zeziganeko eziphawulekayo ze-molecular ziquka:

  • Ukuhlanganiswa kweeprotheni ezibandakanyekayo kulawulo lomjikelo weseli.
  • Ukusebenza kwezinto ezikhulayo ezikhuthaza ukwanda kweeseli.
  • Ukulawulwa komgangatho we-DNA ukubona nawuphi na umonakalo okanye utshintsho.

Isigaba S: Kwesi sigaba, iseli iphindaphinda iDNA yayo ukwenza iikopi ezimbini ezifanayo. Oku kubandakanya uthotho lweziganeko ezibalulekileyo zemolekyuli ukuqinisekisa eyona kopi yemathiriyeli yemfuza, kubandakanywa:

  • Ukukhulula i-DNA double helix.
  • Ukudityaniswa kwamaqhekeza amatsha eDNA ancedisana kumsonto ngamnye wokuqala.
  • Ukudityaniswa kwamaqhekeza eDNA asanda kwenziwa ukwenza iikopi ezipheleleyo.

Isigaba se-G2: Kweli nqanaba, iseli ilungiselela ukwahlukana kweeseli. Iziganeko zemolekyuli ezinxulumene nesi sigaba ziquka:

  • Ukuqhubela phambili kwe-synthesis yeeprotheni eziyimfuneko kwi-cell division.
  • Uvavanyo kunye ⁢nokulungiswa kwawo nawuphi na umonakalo kwi⁢ ephindiweyo ye-DNA.
  • Ulawulo lomgangatho ukuqinisekisa ukuba iimfuno eziyimfuneko zokuqalisa icandelo ziyafezekiswa.

Umjikelo weseli ongasebenziyo: iimpembelelo kunye neziphumo

Umjikelo cell phone yinkqubo ilawulwa kakhulu eqinisekisa ukuphindaphinda okuchanekileyo kunye nokwahlulwa kweeseli. Nangona kunjalo, xa lo mjikelo utshintshwa, iziphumo ezibi kunye neziphumo zinokuvela kumzimba. Apha ngezantsi,⁤ ezinye zeziphumo ezingundoqo⁤kunye⁤ neziphumo zomjikelo weseli ongalawulekiyo ziya kuboniswa:

1. Uphuhliso lwezifo:

Umjikelo weseli ongalawulekiyo unokufaka isandla ekukhuleni kwezifo ezahlukahlukeneyo, ezinjengomhlaza. Xa iiseli zingawulandeli umjikelo weseli ofanelekileyo, zinokubandezeleka kutshintsho kwaye zande ngendlela engalawulekiyo. Oku kunokukhokelela ekubunjweni kwezicubu ezinobungozi ezihlasela izicubu ezijikelezileyo kwaye zisasazeke kwezinye iindawo zomzimba Ngaphandle komhlaza, umjikelezo weseli we-dysregulated unokudibaniswa nezifo zofuzo kunye nokuphazamiseka kophuhliso.

2. Ukwaluphala kwangaphambi kwexesha:

Umjikelo weseli ongalawulekiyo unokukhawulezisa ukuguga kwamaselula kwaye ube negalelo ekugugeni kwangaphambili kwezicubu kunye namalungu. Xa iiseli zingahluli ngokuchanekileyo kwaye ziqokelele umonakalo kwi-DNA yazo, ziba zingasebenzi kwaye zinokungena kwisimo se-senescence okanye ukufa kwangaphambi kwexesha. Oku kunokuba nefuthe elibi kwimpilo kunye nokusebenza kwezicubu, ezikhokelela ekugugeni ngokukhawuleza komzimba.

3. Ukuchaneka kokuphendula komzimba:

Umjikelo weeseli ongalawulekiyo unokuchaphazela indlela amajoni omzimba asabela ngayo. Iiseli zokhuselo lomzimba, ezifana ne-lymphocyte, nazo zilandela umjikelo weseli ukuba zande kwaye zithathe amanyathelo okuzikhusela Ukuba umjikelo weeseli ezi seli uguquliwe, unokubeka esichengeni amandla azo okuchonga kunye nokunciphisa abahlaseli, njengebhaktheriya, iintsholongwane, kunye neentsholongwane. iiseli zomhlaza. Oku kunokuwenza buthathaka amajoni omzimba kwaye awenze angasebenzi kakuhle ekukhuseleni umzimba kwizifo kunye nezoyikiso zangaphandle.

Izixhobo kunye nobuchule bokufunda umjikelo weeseli kwibhayoloji yemolekyuli

Zibalulekile ekuqondeni iinkqubo ezenzeka kwiiseli ngexesha lomjikelo wabo wobomi. Ezi ndlela zisivumela ukuba siphande ukuphindaphinda kwe-DNA, ukuhlukana kwe-chromosome kunye nokwahlula kweeseli, phakathi kwezinye iziganeko eziphambili.

Esinye sezixhobo ezisetyenziswa kakhulu kwisifundo somjikelezo weseli yi-cytometry yokuhamba, evumela ukuhlalutya kunye nobungakanani bezigaba ezahlukeneyo zomjikelezo weseli kuluntu lweeseli. Ukongeza, i-microscopy ye-fluorescence isetyenziswa ngokubanzi ukujonga kunye nokulandela ngexesha langempela iiprotheyini ezahlukeneyo kunye namanqaku angenelela kwiziganeko zomjikelezo weseli.

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Enye indlela ebalulekileyo kukusetyenziswa kweendlela ze-molecular ezifana ne-PCR ngexesha langempela, evumela ⁤intetha​ yemfuza ethile ukuba ibalwe ngexesha lezigaba ezahlukeneyo zomjikelo weseli. Ukongeza, ubuchule bokubhula baseNtshona busetyenziselwa ukufumanisa kunye nokuhlalutya iiprotheyini eziphambili zokulawula umjikelo weseli.

Intsebenziswano⁢ phakathi kwe-cyclin-CDK⁣ kunye nomjikelo weseli

Intsebenziswano phakathi kwe-cyclin kunye ne-cyclin-dependent kinase (CDK) idlala indima ebalulekileyo kulawulo lomjikelo weseli. Ii-Cyclins ziiprotheyini ezihamba ngokuguquguquka kwe-cyclic ngexesha lezigaba ezahlukeneyo zomjikelo weseli. Ii-CDKs, kwelinye icala, zii-enzymes⁤ ezenziwayo kwaye ⁢ezenziwe zingasebenzi ngokubotshwa kwee-cyclin, zenza ii-⁤cyclin-CDK complexes⁢ ziyimfuneko ukulawula ukuqhubeka komjikelo weseli.

Umjikelo weseli unezigaba ezininzi, kubandakanya i-G1, S, G2, kunye nesigaba se-M Ngexesha le-G1, iiseli zilungiselela ukuphindaphinda kwe-DNA kunye nokukhula kweeseli. Umsebenzi wee-CDK ezixhomekeke kwi-cyclin uphantsi ekuqaleni kwesi sigaba, kodwa ngokuthe ngcembe ukhula njengoko ii-cyclins ziqokelela. Kwinqanaba le-S, i-DNA iyaphindwa kwaye ii-CDKs zinegalelo kulawulo lwe le nkqubo. Emva koko, kwisigaba se-G2, iiseli zilungiselela ukuhlukana kweeseli ngokuvelisa iiprotheyini eziyimfuneko zokuhlukana kwezinto zofuzo Ekugqibeleni, kwisigaba se-M, ii-CDK zilawula ukuhlukana okuchanekileyo kwe-chromosomes kunye ne-cytokinesis.

Ukusebenzisana phakathi kwee-cyclins kunye nee-CDK zilawulwa kakhulu kwaye zilawulwa yi-phosphorylation kunye neendlela zokunciphisa i-proteasomal. Ezi ndlela ziqinisekisa⁢ ukuba iikhompleksi ze-cyclin-CDK zenziwe ngexesha elifanelekileyo⁤ kunye nobungakanani obuyimfuneko ⁢inqanaba ngalinye lomjikelo ⁢seseli. Ukongezelela, ezinye iiprotheni ezibizwa ngokuba yi-CDK inhibitory kinases (CKIs) ziphinde zilawule umsebenzi we-CDK kwaye zithathe inxaxheba ekubanjweni komjikelo weseli xa kufunyenwe umonakalo we-DNA okanye xa iimeko zokwahlulwa kweeseli zingekho.

Iimpawu zeemolekyuli zomjikelo weeseli kunye nokusetyenziswa kwazo

Umjikelo weseli yinkqubo apho iiseli ziphindaphinda kwaye zahlulwe zibe ziiseli ezimbini zeentombi. ⁤Le nkqubo ilawulwa ngokungqongqo ngoluhlu lwabamakishi bemolekyuli abalawula izigaba zomjikelo weeseli. Ezi ziphawuli ziiprotheyini ezithile ezidlala indima ebalulekileyo ekulawuleni ukukhula nokwahlula kweeseli.

Ukusetyenziswa kwabamakishi beemolekyuli zomjikelezo weseli kunoluhlu olubanzi lwezicelo kuphando kunye neyeza. Ezi makishi zisivumela ukuba sihlalutye kwaye siqonde ngcono iindlela zomjikelo weseli, kunye nokuchonga utshintsho olunokwenzeka olunokuthi lubhekiselele kwizifo ezinjengomhlaza. Ukongeza, iimpawu zeemolekyuli zingasetyenziselwa ukuvavanya ukusebenza konyango lomhlaza kunye nokuxela kwangaphambili i-prognosis yezigulane.

Ezinye zezona ziphawuli ziqhele ukusetyenziswa kwimolekyuli kuphononongo lomjikelo weeseli ziquka:

  • p53 protein: iprotein ye-tumor suppressor elawula ukubanjwa komjikelo weseli kwaye ibangele ukufa kweseli okucwangcisiweyo kwimeko yomonakalo weDNA.
  • I-CDK (i-cyclin-dependent kinase): i-enzymes eziphambili ezilawula ukuqhubela phambili komjikelezo weseli ngokuzibophelela kwii-cyclins ezithile.
  • Iprotheyini ye-Ki-67: isalathisi sokunyuka kweeseli esetyenzisiweyo njengesalathisi somsebenzi weselula kunye neqondo lobubi kwiindidi ezahlukeneyo zamathumba.

Ukuqukumbela, iziphawuli zemolekyuli⁤ ze umjikelo cell are izixhobo ezisisiseko kuphando nakunyango. Ukusetyenziswa kwayo kusivumela ukuba siqonde ngcono iinkqubo zeselula kunye nokuxilongwa kweenguqu ezinxulumene nezifo. Ngaphaya koko, ezi mpawu zibalulekile kuphuhliso lonyango olusebenzayo ngakumbi kunye nakunyango lomhlaza.

Ukulawulwa komjikelo weeseli: iimpembelelo zonyango kwizifo

Ukuqonda ulawulo lomjikelo weseli Ibalulekile ekuphuhliseni unyango olusebenzayo ngokuchasene nezifo ezahlukeneyo. Umjikelo weseli yinkqubo elawulwa kakhulu equka izigaba ezahlukeneyo, ezibandakanya ukuphindaphinda kwe-DNA kunye nokwahlulwa kwe-chromosome, ngaloo ndlela ivumela ukukhula kweeseli kunye nokwahlukana. Utshintsho kule nkqubo kunokukhokelela kwizifo ezinjengomhlaza, apho iiseli ziqhubeka nokwahlukana ngokungalawulekiyo.

Enye yezona ziphumo zonyango ezithembisayo zokulawula umjikelezo weseli yinto enokwenzeka yokuphuhlisa iziyobisi ezisebenza kwiiprotheni eziphambili ezibandakanyekayo ekulawuleni kwayo Ngokomzekelo, ukuchongwa kwe-inhibitors ye-kinases, i-enzymes elawula ukuqhubela phambili ngomjikelezo weseli, uye wabangela ukuba kuqhutywe umjikelezo weseli. uphuhliso lwezonyango zomhlaza ekujoliswe kuzo. Ezi inhibitors zinokuvala umsebenzi we-kinases ethile, ngaloo ndlela iphazamise ukwanda okungalawulwayo kweeseli zomhlaza.

Olunye unyango olubalulekileyo ⁤impembelelo⁣ kuphuhliso lweendlela zokuxilonga⁤ ezivavanya ⁢imeko yomjikelo weseli kwiiseli zethumba. Ezi mvavanyo zinokunceda ekuqinisekiseni ubundlongondlongo besifo kunye nokusebenza okunokwenzeka konyango oluhlukeneyo Ukongeza, ukuqonda iindlela zokulawula umjikelo weseli kuvula umnyango weendlela ezintsha zonyango, ezifana nokumodareyithwa kweeprotheni umsebenzi kunye nokubuyisela ulawulo oluqhelekileyo lomjikelo weseli kwiiseli ezigulayo.

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Inkqubela phambili yakutsha nje ekuqondeni umjikelo weeseli ngebhayoloji yemolekyuli

Ibhayoloji yeemolekyuli ibe sisixhobo esisisiseko sokutyhila iimfihlelo zomjikelo weeseli, inkqubo ebalulekileyo ekukhuleni nasekukhuleni kwezinto eziphilayo. Enkosi kwinkqubela phambili yamva nje kolu qeqesho, kube nokwenzeka ukuqonda ngokuchanekileyo ngakumbi iindlela zemolekyuli ezilawula isigaba ngasinye somjikelo weeseli.

Phakathi kwezinto eziphawulekayo ezifunyenweyo kukuchongwa kweeprotheni ezintsha ezibandakanyekayo ekulawuleni umjikelo weseli, osebenza njengotshintsho lwemolekyuli olulawula ukuqhubela phambili okanye ukubanjwa komjikelo. Ezi protheni, ezifana ne-cyclin kunye ne-cyclin-dependent kinases (CDKs), ziye zaba ngumxholo wophando olunzulu kunye nokubaluleka kwazo ekusebenzeni ngokuchanekileyo komjikelezo weseli kuye kwagqitywa.

Enye inkqubela ebalulekileyo ibikukufunyanwa kwezona ndawo zibizwa ngokuba zii-cell cycle checkpoints. La manqaku ngamanqanaba aphambili kumjikelo oqinisekisa ukuba isigaba sangaphambili sigqitywe ngempumelelo ngaphambi kokuba sidlulele kwelinye. Uphononongo lwakutsha nje lubonakalise ubukho beendawo zokukhangela ezininzi, ezifana ne-G1 kunye ne-G2 yokukhangela, eqinisekisa intembeko ye-DNA kunye nokuphinda-phindwa okuchanekileyo kwemathiriyeli yemfuzo phambi kokwahlulwa kweseli.

Iimbono zexesha elizayo kuphando lomjikelo weeseli usebenzisa ibhayoloji yemolekyuli

Ekuqhubeni uphando lomjikelo weeseli kusetyenziswa ibhayoloji yemolekyuli, kukho iimbono ezithembisayo zexesha elizayo ezinokusikhanyisela kwiindlela ezintsonkothileyo ezilawula ukwanda kweeseli kunye nokwahlulahlula. Njengoko iteknoloji iqhubela phambili, kuvela izixhobo ezintsha kunye neendlela ezivumela ukuqonda okunzulu kule nkqubo isisiseko ebomini beeseli.

Amanye amathemba aphawulekayo kwixesha elizayo aquka:

  • Ukuchongwa kwabalawuli abatsha beeseli: Ngokusebenzisa ubuchule obuphezulu obufana nokulandelelana kwe-RNA kunye nohlalutyo lweprotheyini, kunokwenzeka ukuba kufumaneke amacandelo amatsha abalulekileyo abandakanyekayo kulawulo lomjikelo weeseli Ezi zifunyanwe zingatyhila iithagethi eziNtsha zonyango zonyango lwezifo ezinxulumene nokunyuka kweeseli ezingalawulwayo.
  • Ukuphonononga umjikelo weseli ⁤heterogeneity: Nangona umjikelo weseli ufundwe kakhulu kwi-homogeneous cell populations, kukho ubungqina obandayo bobukho be-cell subpopulations ezineempawu ezahlukeneyo kunye neepateni zokwahlula. Ukusetyenziswa kwetekhnoloji yeeseli enye, njengokulandelelana kwe-RNA yeseli enye, ivumela ukujongana ne-heterogeneity yeseli kunye nokuqonda ngcono ukuba kulawulwa njani kwiimeko ezahlukeneyo ze-physiological and pathological.
  • Uhlalutyo⁤ lolawulo lwe-epigenetic lomjikelo weseli: Ukuguqulwa kwe-Epigenetic, okufana ne-DNA methylation kunye nokuguqulwa kwe-histone, kuye kwabonwa ukuba kudlala indima ebalulekileyo kulawulo lomjikelo weeseli. Uphando lwexesha elizayo luya kugxila ekuqondeni indlela ezi nguqulelo ze-epigenetic ezichaphazela ngayo i-gene expression ngexesha lezigaba ezahlukeneyo zomjikelezo weseli kunye nendlela enokusetyenziswa ngayo ngonyango ukulawula ukwanda kweeseli.

Isishwankathelo, uphando lwexesha elizayo kwicandelo lomjikelo weeseli kusetyenziswa ibhayoloji yeemolekyuli lubonisa indawo ebanzi enokwenzeka. Ukuphuhliswa nokusetyenziswa kobuchule obutsha kunye neendlela kuya kwenza ukuqonda okupheleleyo kunye neenkcukacha zeendlela ezilawula le nkqubo isisiseko kwibhayoloji yeeseli, kwaye kunokuba nefuthe elibalulekileyo kuthintelo kunye nonyango lwezifo ezinxulumene nokwanda okungaqhelekanga kweeseli.

Iimbono kunye neZigqibo

Ukuqukumbela, uphononongo lomjikelo weeseli kwibhayoloji yemolekyuli ludlala indima ebalulekileyo ekuqondeni iinkqubo ezenzeka ngaphakathi kweeseli. Kulo lonke eli nqaku, siye sahlola iinkalo ezahlukeneyo zomjikelezo weseli, ukusuka kwisigaba sokuphindaphinda kwe-DNA ukuya kukwahlulwa kweechromosomes ngexesha le-mitosis. Siye sahlalutya kwakhona ukulawulwa komjikelo weseli kunye nemiphumo yokungasebenzi kwayo kwizifo ezahlukeneyo, ezifana nomhlaza.

Ngokuhambela phambili kwetekhnoloji, ibhayoloji yemolekyuli ivumele uhlalutyo oluneenkcukacha ngakumbi kunye noluchanekileyo lomjikelo weseli, inika isiseko esiluqilima sophuhliso lonyango olusebenzayo ngakumbi kunye nonyango. Ukuqonda iindlela zeselula ezibandakanyekayo kule nkqubo kubalulekile ekukhangeleni izisombululo kwiipathologies ezahlukeneyo kunye nokuphazamiseka.

Isishwankathelo, ibhayoloji yemolekyuli yomjikelezo weseli yinkalo yokufunda eqhubekayo eqhubeka nokutyhila ukuqonda okutsha kububunzima kunye nokuchaneka kweenkqubo zeselula. Oku kuqonda kunempembelelo ebalulekileyo kwintsimi yezempilo kwaye idlala indima ebalulekileyo kuphando kunye nophuhliso lwezonyango ezintsha. Siqinisekile ukuba eli nqaku libonelele ngoshwankathelo olubanzi nolungqongqo kwesi sihloko sinomdla, kwaye sinethemba lokuba abafundi baye baqonda ngakumbi ngokubaluleka kwebhayoloji yeemolekyuli kumjikelo weeseli.