Gene mutations. Multiple Allelism

Multiple allelicism inogadzira phenotypic heterogeneity munharaunda yevanhu. Izvo, zvakare, ndeyedzimwe nheyo dzehutano hwegeneji. Multilic allelicism inokonzerwa nekuchinja kwemajini kunoshandura kuenzanirana mune zvidzidzo zve nitrogenous DNA molecule pane imwe nzvimbo inofananidzwa neimwe gene. Izvi zvinochinja zvinogona kuva zvinokuvadza, zvinobatsira kana zvematongerwe enyika. Shanduko inokuvadza inokonzera hutachiwana hwehutano, huripo huwandu hwevanhu vose hunosanganiswa. Somuenzaniso, kuchinja kunozivikanwa kunoshandura chimiro mune rimwe remaketani e hemoglobin protein kuburikidza nekushandura kodhi yemagidamic acid muvhaini (amino acid) code mumagetsi panzvimbo yekupedzisira. Somugumisiro wekushandura uku, hupenyu hwehutano hunowedzera, sa sickle cell anemia. Overdominization inokonzerwa nekuti muhurumende ye heterozygous pane kuratidzwa kwakasimba kwemasero anotenderera kupfuura mune homozygous. Ichi chinoshamisa chinopindirana nemigumisiro yeheterosis uye ine kubatana nezviratidzo zvakadai sokutarisira kweupenyu hwose, hutano nezvimwe. Mumunhu, kufanana nedzimwe eukaryotes, kukanganisa kwakawanda kunoratidzwa nenzira dzakasiyana-siyana. Kunewowo nhamba huru yevanhu veMendelian, iyo inotsanangurwa nekubatana kwakasiyana. Zvinyorwa zvese zvakasiyana-siyana zvakasiyana-siyana zvinowanikwa mune rimwe gene, riri mumakromosomes e homologous, munzvimbo imwechete.

Paunofanotaura nezvenhaka uchishandisa mitemo yeMendelian, zvinokwanisika kuverenga mukana wekuonekwa kwevana neiyo kana iyo yekufananidzira. Kuti uongorore kuchinja kwezvinhu kubva kuchizvarwa kusvika kune rimwe chizvarwa, nzira yakanakisisa yekugadzira nzira ndiyo inonzi genealogical method, inobva pakuvakwa kwe pedigrees.

Izvo zvinofanira kuonekwa kuti phenotypic kuratidzwa kwejena rimwe rinokanganiswa nemamwe majini. Semuenzaniso wekubatana kwemajini, nguva dzose munhaka yeRh-factor system inogona kuitika : Rh negative uye Rh plus. Muchiitiko chekudzidza muna 1939 ropa remuviri wemurwere akaberekera mwana akafa uye akawedzerwa ropa romurume anokwirirana neboka reABO munhoroondo yechirwere, zvirwere zvinoratidzwa. Vakatumidzwa kuti Rh-antibody, uye boka revarwere reropa raiva Rh-negative. Rhesus-positive ropa boka rinotsungirirwa nekuvapo kwepamusoro masero matsvuku eropa eboka rakasiyana reantigens rakakonzerwa nemajeni edzimba. Ivo, ivowo, vanotakura mashoko pamusoro pe membrane polypeptides.

Zvinokonzera kuderera kukuru muhupenyu uye kutungamirira kurufu rwemuviri unofa. Izvo zvakakamurwa kuva mapoka maviri. Ikutanga inosanganisira maitiro akawandisa. Vanomutsa rufu rwemuviri bedzi muhurumende yekutenderera. Boka rechipiri rine rine maitiro makuru. Zvavanoita zvinogonawo kuitika munharaunda ye heterozygous.

Kuratidzwa kwemajini anouraya kunogona kuonekwa pamatanho akasiyana ekugadzirwa kwevanhu. Aya ndiwo matanho okutanga (embryonic mortality), uye zvikamu zvakaderera zvikuru (fetal death, zvichikonzera kubvisa pamuviri kamwechete, kuberekwa kwezvisikwa zvisingachinji). Mukuwedzera kune zvinouraya, hafu-inouraya mazamu anozivikanwawo. Havatambudzi kufa nekukurumidzira kwemuviri, asi kunonyanya kuderedza kushanda kwayo.

Majoini anouraya anowanikwa ari munhamba shomanana zvikuru kana achienzaniswa nechekare. Izvozvo zvinoshandiswa ndezvomutambo mukuru. Zvinotakura zvemajini makuru, kana zvichidikanwa, zvinogona kubviswa nyore nyore kubva pakuzvara, sezvo vane chimiro che phenotype. Chikamu chemajini anouraya chinokonzera kukanganisa kukuru, imwe chikamu-kuparara kwehupenyu hwehutano.