Mowiriza kusintha: gulu, zimayambitsa Zitsanzo

Kodi amatchedwa mowiriza kusintha? Ngati kulanda akuti m'chilankhulo zilipo, ndi zolakwa zachilengedwe zikuchitika pa ntchito mogwirizana kwa zinthu majini ku malo mkati ndi / kapena kunja. masinthidwe amenewa amakhala mwangozi. Iwo anati kugonana, ndi maselo ena a m'thupi.

Exogenous chimachititsa masinthidwe

masinthidwe mowiriza angayambe atamwa mankhwala, poizoni pansi zochita za kutentha kapena otsika, mpweya wochepa thupi kapena kuthamanga.

Chaka chilichonse, anthu ambiri amadya chimodzi pa zinthu khumi okonzeka ionizing cheza omwe zachilengedwe maziko poizoniyu. Chiwerengero chimenechi chikuphatikizaponso Popanga madzi a gamma kutentha kwa dziko lapansi pakati, mphepo dzuwa, magulu nyukiliya, m'manja mwa unyinji wa kutumphuka ndi kusungunuka mu mlengalenga. Mlingo chifukwa chimadaliranso kumene kuli anthu. A kotala ya onse kusintha mowiriza chimachitika ndi vuto la chinthu ichi.

Ultraviolet poizoniyu, mosiyana ndi zimene anthu ambiri amaganiza, kumathandiza zazing'ono ntchito ponyengerera DNA kuwonongeka, monga iwo sangalowerere mwakuya kwambiri mu thupi la munthu. Koma khungu zambiri amadwala insolation kwambiri (khansa, khansa zina). Komabe, zamoyo zokhala ndi selo imodzi ndi mavairasi mutate pamene dzuŵa.

Kwambiri kutentha kapena otsika kwambiri zingachititse kusintha zinthu chibadwa.

Amkati chimachititsa masinthidwe

zifukwa zazikulu chifukwa chimene kusintha mowiriza angayambe, zinthu amkati. Zikuphatikizapo mbali zinthu za kagayidwe Zolakwika pa kugawanika kukonza ndi recombination, ndi ena.

1. Kulephera kugawanika:
   - kusintha padera ndi inversions zapansi nitrogenous;
   - Kusagwiritsa mayikidwe a nucleotides zolakwa DNA polymerases;
   - mankhwala m'malo nucleotides, monga guanine-cytosine kuti adenine-guanine.
2. zolakwa kukhazikitsanso:
   - masinthidwe majini udindo yokonza zigawo munthu wa DNA timafupa pambuyo yopuma awo mchikakamizo cha zinthu zina.
3. Mavuto ndi recombination ndi:
   - zolephera kusinthanitsidwa ndondomeko pa chifukwa meiosis ndi mitosis mu mpweya ndi kutambasuka kwa zapansi lapansi.

Izi ndi zinthu zazikulu kuchititsa masinthidwe lachibadwa. Zimayambitsa kulephera akhoza kukhala kuti yambitsa majini mutator komanso kutembenuka kwa mankhwala otetezedwa ku metabolites yogwira zokhudza selo phata. Komanso pali zifukwa structural. Zikuphatikizapo mobwerezabwereza nyukiliotayidi mindandanda pafupi ndi dera malo kusintha, pamaso pa zigawo zina DNA ofanana mu dongosolo kuti matupi athu, komanso ngati zinthu makina a matupi athu ndi.

pathogenesis masinthidwe

Mowiriza kusintha kumachitika chifukwa cha mmene zinthu zonsezi zimene zimakhudza, pamodzi kapena payekhapayekha mu nyengo zina za moyo wa khungu. Pali chinthu monga ukuyenda mating kuphwanya wocheperapo ndi DNA chingwe akuchikazi. Chifukwa, kawirikawiri anapanga kuchokera zingwe zopota peputayidi, amene sangathe mokwanira cigawo mu ndondomeko ya. Pambuyo kuchotsa mbali zosafunika ya DNA unyolo wocheperapo zingwe zopota mungathe onse resected (kufufutidwa) ndi Integrated (duplications, insertions). kusintha aswa ndi kuliika m'zinthu zotsatirazi kuimira selo.

Liwiro ndi chiwerengero cha masinthidwe amadalira dongosolo yaikulu ya DNA. Asayansi ena amakhulupirira kuti ndi mwamtheradi DNA mbali zonse mutagenic ngati iwo apanga anaŵerama.

Ambiri masinthidwe mowiriza

Kodi nthawi zambiri akuwonetseredwa mu nkhani chibadwa cha masinthidwe mowiriza? Zitsanzo za zinthu zimenezi - kutaya zapansi nitrogenous ndi pochotsa amino zidulo. Makamaka tcheru iwo amaonedwa zatsalira cytosine.

Iwo imatsimikizirika kuti lero oposa theka la inakhala ali ndi kusintha kwa zatsalira cytosine. Pambuyo deamination methylcytosine lisinthike kuti thymine. Yotsatira ya chigawo chino akubwereza kulakwitsa kapena deletes kapena awiriawiri ndipo mutates kwa mpukutu watsopano.

Chinthu china pafupipafupi masinthidwe mowiriza imatengedwa ambiri pseudogenes. Chifukwa cha ichi, m'kati meiosis akhoza kupangidwa wosiyana magazi recombination. Izi zimachititsa kusintha chibadwa cha ankasinthana munthu ndi mbali anawaonjezera kuwirikiza kawiri nyukiliotayidi.

Polymerase chitsanzo mutagenesis

Malinga ndi chitsanzo ichi, masinthidwe mowiriza ndizo zotsatira za mwachisawawa zolakwa mamolekyulu, synthesizing DNA. Kwa nthawi yoyamba chitsanzo ichi waperekedwa ndi Bresler. Iye anandiuza kuti masinthidwe zimachitika chifukwa chakuti mu zina, polymerase ndi anaikapo mu ndondomeko ya nucleotides nekomplimentarnye.

Patatha zaka mayesero yaitali ndi zatsopano, zimenezi kwavomelezedwa ndi m'dzikoli sayansi. Panali anachotsa malamulo ena amene amalola asayansi kulamulira ndi masinthidwe mwachindunji malinga ndi ultraviolet DNA zigawo yeniyeni. Mwachitsanzo, anapeza kuti kutsogolo kwa triplet zowonongeka zambiri anamanga adenine.

Tautomeric chitsanzo mutagenesis

chiphunzitso china kufotokoza padera ndi kupanga masinthidwe anali bungwe Watson ndipo Crick (otulukira kukonza DNA). Iwo adati mutagenesis zochokera luso la ena m'munsi DNA anatembenukira kwa mitundu ya tautomeric, kusintha zapansi kugwirizana njira.

Potsatira buku la kungoganizira wakhala akufunafuna mwakhama otukuka. mitundu yatsopano ya nucleotides anali wapezeka pambuyo walitsa ndi kuwala ultraviolet. Izi anapereka asayansi mwayi latsopano kafukufuku. sayansi yamakono akadali ikufotokoza udindo wa mitundu tautomeric mu mutagenesis padera ndi imakhudzira chiwerengero cha masinthidwe wapezeka.

zitsanzo zina

Mowiriza kusintha angakhale kuphwanya kuzindikira DNA polymerase zidulo mkati. Poltaevym neri Al anaimveketsa limagwirira kuti enforces mapolojekiti mfundo mu kaphatikizidwe DNA mamolekyulu bulanchi. chitsanzo Zimenezi zinachititsa kuti kuphunzira chito za limapezekapezeka mutagenesis lachibadwa. Ofufuzawa anafotokoza anatulukira kuti chifukwa chachikulu kusintha kapangidwe ka DNA kaphatikizidwe ndi sanali ovomerezeka m'munsi awiriawiri.

Iwo adafotokoza kuti chifukwa lililonse kumachitika chifukwa deamination ya DNA. Zimenezi zimabweretsa kusintha cytosine kuti thymine kapena uracil. Chifukwa cha masinthidwe awa anapanga awiri nucleotides atakwatirana. Choncho, pa kugawanika lotsatira amapezeka kusintha (dontho m'malo nucleobases).

Gawo cha masinthidwe: mowiriza

Pali classifications osiyana cha masinthidwe kutengera mtundu wa muyeso lili pakati awo. Pali kugawinikana khalidwe kusintha jini ntchito:

- hypomorphic (mutated alleles lithe zochepa zomanga thupi, koma iwo ofanana choyambirira);
- amorphous (jini linasiiratu ntchito yake);
- antimorfnye (mutated jini imadzitembenuzanso chizindikiro chimene);
- neomorfnye (pali zinthu zatsopano).

Koma gulu wamba lomwe limapanga malire masinthidwe onse mogwirizana ndi dongosolo variable. wolemekezeka:

1. kutengera mapangidwe masinthidwe. Zikuphatikizapo polyploidy, mwachitsanzo mapangidwe matupi athu ndi patatu, komanso DNA, ndipo aneuploidy - chiwerengero cha DNA matupi athu si angapo a haploid lapansi.
2. Chromosomal kusintha. Pali kukonzanso kwambiri zidutswa DNA. Kusiyanitsa imfa ya mudziwe (kufufutidwa), anawaonjezera kuwirikiza kawiri ake (mwendo), kusintha lathu la mindandanda nyukiliotayidi (inversion), komanso malo kutengerapo pa DNA malo ena (translocation).
3. Chibadwa kusintha. The masinthidwe ambiri. Unyolo DNA m'malo mwachisawawa zapansi angapo nitrogenous.

Zotsatira za masinthidwe

Mowiriza masinthidwe - kumayambitsa matenda zotupa yosungirako, kukanika ziwalo ndipo zimakhala za anthu ndi nyama. Ngati khungu mutated lili lalikulu multicellular chamoyo, m'pamenenso iwo lidzawonongedwa ndi kukhazikitsidwa kwa aputosisi (ma selo imfa). thupi akulamulira ndondomeko ya kusamala chuma majini, ndi mothandizidwa ndi chitetezo cha m'thupi kamakhala kuchotsa maselo onse zotheka kuonongeka.

Ngati munthu wa masauzande T-lymphocytes alibe nthawi kuzindikira dongosolo akhudzidwa, ndipo amapereka maselo choyerekeza kuti muli jini mutated. selo yense ali ntchito kale zina, amabala poizoni ndi kusokoneza chikhalidwe ambiri a thupi.

Ngati palibe kusintha zinachitika mu somatic ndi nyongolosi selo, kusintha adzakhala anati mu mbewu. Amasonyeza kuvutika kobadwa nako ziwalo, deformities, matenda kagayidwe kachakudya, ndi matenda yosungirako.

Mowiriza masinthidwe: phindu

Nthawi zina, poyamba zinkaoneka masinthidwe achabechabe angakhale othandiza kuti azolowere zinthu yatsopano ya moyo. Izi ndi kusintha ngati muyeso wa kusankha zamoyo. Nyama, mbalame ndi tizilombo ndi kubisa coloration lolingana malo okhala kudziteteza kwa adani. Koma ngati kusintha malo awo, ndiye ntchito kusintha kwa chikhalidwe amayesetsa kuteteza mitundu chithe. M'mikhalidwe latsopano la Zamphamvu moyo ndi kupereka mphamvu kwa ena.

The kusintha angayambe m'madera sanali yogwira matupi athu, ndiyeno kuona kusintha kwa fenotayipi anati. Kupeza "breakage" n'chotheka kudzera mwa maphunziro enieni. M'pofunika kuphunzira chiyambi cha mitundu zokhudza nyama ndi yokonza mapu awo majini.

Vuto cha masinthidwe mowiriza

Mu makumi anai Mu zaka zapitazo panali ganizo kuti kusintha anachititsa potsatira zinthu zina ndi kuthandiza iwo atengere. Kuyesa chiphunzitso ichi, ndi wapadera mayesero reps njira anayamba kupanga.

Ndondomeko chinali chifukwa chakuti ochepa mtundu umodzi wa bakiteriya ali yokutidwa pa chubu ndi pambuyo kumezetsanitsa mankhwala angapo adaonjezeredwa ku izo. Part tizilombo anapulumuka, ndipo anawatengera ku malo atsopano. Kuyerekezera mabakiteriya machubu osiyana anasonyeza kuti kukana anauka zokha monga zolankhulirana ndi mankhwala, ndipo pambuyo.

kubwerezabwereza njira anali kuti fleecy nsalu kunditumiza ku tizilombo, ndiyeno anasamutsa imodzi mu mapangidwe angapo woyera. madera atsopano anali otukuka ndi mankhwala mankhwala opha tizilombo toyambitsa. Chifukwa cha zimenezi, mabakiteriya osiyanasiyana anapulumuka machubu anakonza pa mbali ofanana a sing'anga.