MUTAGENEZ

MUTAGENEZ (az lotini mutatio — tagyiryoby va …genez), prosessi tag-yiryobii irsi — mutasiyaro guyand, ni az tasiri sharoithoi tabii (khud az khud) yo omilhoi gunoguni fiziki yo khimiyavi mutagenho ba vujud meoyad. Asosi Mutagenezro tagyiryobii molekulahoi kislotahoi nukleat, ki nigahdor va noqili akhbori irsi meboshand, tashkil medihand. In tagyiryobi chun mutasiyami geni yo tashakkuli navi khromosomaho ifoda mebbad. Mekhanizmi Mutagenez baroi mutagenhoi gunogun har khel ast. Afkanishi ionizonanda ba kislotahoi nukleat bevosita tasir namuda, atomhoi onhoro faol va ionizasiya mekunad. In boisi kanda shudani silsilai (zanjiri) angishtobu fosfatii molekula va bandhoi gidrogenii bayni torhoi komplementarii KDN (kislotai dezoksiribonukleat) megardad.

Ba rafti Mutagenez omilhoi gunoguni beruni tasiri ziyod merasonand, masalan, dar zeri tasiri afkanishi ionizonanda surati mutasiyaho hangomi ba hujayra dokhilshavii oksigen afzuda, hangomi norasoii on (agar afkanish dar atmosferai nitrogen ba vujud oyad) sust meshavad. Baze moddaho M.utagenezro bozmedorand. Masalan, ba khujayra dokhil namudani adenozin yo guanozin tasiri mutagenii analoghoi purinii asoshoi nitrogeniro bozmedorand, fermenti katalaza effekti mutagenii afkanishi ionizo-nandaro sust mekunad. Hangomi tasiri baze mutagenhoi khimiyavi mutasiya yakbora yo badi chand vaqt, bazan badi yakchand nasli huyaayra ivaz shudan ba vujud omada metavonad.