Ingabe i-telomeres ingachaza ukuguga?
Ukutholakala kwama- telomeres kwashintsha ngokuphelele indlela abacwaningi abacwaninga ngayo isikhathi eside kanye nenqubo yokuguga. Eqinisweni, abacwaningi abathola ama-telomeres bawina umklomelo weNobel ePhysiology noma Medicine ngo-2009. I-Telomeres yizinkinobho "ze-DNA ezingenamuthi" ezisezintabeni zama- chromosomes . Zivikela i-DNA yakho yangempela njalo uma iseli lihlukanisa.
Ngaso sonke isikhathi lapho i-cell ihlukanisa, i-DNA iyaphazanyiswa, futhi ulwazi ngaphakathi lukopishiwe.
Ngenxa yokuthi amangqamuzana ahlukana kanjani, leyo nhlobo yokugcina ye-chromosome, i-telomere, ayikwazi ukukopishwa ngokuphelele. Kancane kancane kufanele kunqunywe. Kucatshangwa ukuthi, njengoba iseli lihlukanisa, ama-telomeres abe mfushane futhi afushane isikhathi ngasinye kuze kube sekupheleni. Kuleli qophelo, i-DNA okuthiwa "yangempela" ayikwazi ukukopishwa futhi iseli liyiminyaka nje futhi alisakwazi ukuphindaphindiwe.
Okushiwo Ucwaningo Mayelana Ne-Telomere Ukunciphisa Nokuguga
Emiphakathini yezinga labantu, abacwaningi bathole ukuthi abantu asebekhulile banama-telomere ambalwa. Ekugcineni, amaseli anama-telomeres ambalwa angeke aphinde aphindaphindiwe. Lokhu kuthinta amangqamuzana amaningi nangaphezulu ngokuhamba kwesikhathi, okuholela ekulimaleni komzimba kanye nezibonakaliso ezesabekayo futhi.
Amangqamuzana amaningi angaphinda aphindwe izikhathi ezingaba ngu-50 ngaphambi kokuba ama-telomeres abe mfushane kakhulu. Abanye abacwaningi bakholelwa ukuthi ama-telomere athiwa "yimfihlo yokuphila isikhathi eside" nokuthi kunezimo lapho ama-telomere angeke anciphise khona.
Isibonelo, amangqamuzana omdlavuza awafi (okuyinto inkinga enkulu) ngoba asebenze i-enzyme ebizwa ngokuthi i- telomerase enezela kuma-telomeres lapho amangqamuzana ehlukana.
Wonke amangqamuzana emzimbeni anamandla okukhiqiza i-telomerase, kodwa amaseli athile kuphela - kuhlanganise amaseli e-stem, amangqamuzana omzimba, namaseli egazi amhlophe - adinga ukukhiqiza i-enzyme.
Lawa maseli adinga ukuphindaphinda izikhathi ezingaphezu kuka-50 phakathi nesikhathi sokuphila, ngakho ngokukhiqiza i-telomerase abathintekile ngokunciphisa i-telomere.
Ama-telomere amancane awahlanganiswa kuphela nobudala kodwa nezifo nawo. Eqinisweni, ubude obuncane be-telomere kanye nomsebenzi ophansi we-telomerase kuhlotshaniswa nezifo eziningana ezingavinjelwe ezingavamile. Lokhu kuhlanganisa ukushisa komfutho, isifo senhliziyo, ukushukela kwe-insulin, uhlobo lwesifo sikashukela sohlobo lwesibili, ukucindezeleka, i-osteoporosis, nokukhuluphala.
Ingabe Kukhona Wonke Umuntu?
Cha. Futhi lokho kuyamangaza okukhulu. Abacwaningi baseSweden bathola ukuthi ama-telomere abantu abathile abatholi isikhathi esifushane. Eqinisweni, bathola ukuthi ama-telomeres abanye abantu angase afike isikhathi eside. Lokhu kuhluka ezingeni elilodwa kwakungabonakali yizifundo zangaphambilini ezaba nomphumela olinganisiwe phezu kwabantu abaningi.
Esifundweni, abantu abangu-959 banikele ngegazi kabili, iminyaka engu-9 kuya kweyi-11 ehlukene. Ngokwesilinganiso, amasampula wesibili anama-telomeres ambalwa kunowokuqala. Kodwa-ke, cishe amaphesenti angu-33 alabo abafundela babe nobude obuqinile noma obandayo be-telomere esikhathini esingangeminyaka engaba ngu-10.
Kusho ukuthini lokhu? Akucacile. Kungenzeka ukuthi labo bantu banezinqubo ezimangalisayo zokulwa nokuguga; Kungenzeka ukuthi banesibindi sokuqala somdlavuza (abacwaningi bazama ukulawula lokhu ngaphandle), noma kungaba okungenasisekelo.
Lokho esikwaziyo ngokuqinisekile ukuthi ukuguga kuyinkimbinkimbi kakhulu kunokuba nje ubuke ukuncishiswa kwama-telomeres.
Izwi elivela
Umbono we-telomere ungenye yezinkolelo zokuguga . Lena yinsimu ethuthukayo, futhi okutholakala okusha kungakuphikisa noma kungaholela ekusebenziseni le mbono ukuthuthukisa ukwelashwa kwezifo nezimo.
> Imithombo:
> Nordfjäll K, Svenson U, Norrback KF, Adolfsson R, Lenner P, Roos G. Isilinganiso somuntu ngamunye we-cell telomere isilinganiso sokulinganisa isikhathi eside. I-PLoS Genetics, February 13, 2009 DOI: 10.1371 / journal.pgen.1000375