Adaptivna mutacija: bomo preziveli genetske vescine bakterij?

Abstract

The origin and dynamics of genetic variations is one of the key questions in the modem science that has still not come out with a final answer. Emerging concepts regarding genetic variation have always produced a great controversy because they hold a key to unlock a great mystery of evolution. With such a powerful motivation scientist working in the molecular biology, genetics and biochemistry gathered a vast amount of experimental data showing us that a genome is a dynamic, hierarchically organized and complex integrated system for storing and processing information. Dynamic balance between stability and mutability of DNA nucleotide sequences is essential for a proper functioning of the organism. Beside many DNA repairing proteins and DNA protective mechanisms organisms possess also biochemical systems capable of changing DNA information. One of the most controversial and at the same time the most informative one is a phenomenon called adaptive mutation. We shall review findings concerning the phenomenon of adaptive mutation in prokaryotes and point out an urgent need for the upgrade of the awkward neo-darvinistic view on the origin .of the genetic variation.Izvor in dinamika genetskih variacij je eden od kljucnih vprasanj modeme znanosti, ki se vedno caka na dokoncen odgovor. Koncepti v zvezi z genetskimi variacijami povzrocajo veliko polemik, saj nosijo kljuc do skrivnosti evolucije. Molekularni biologi, genetiki in biokemiki, so zavoljo tako mocnega motiva zbrali ogromno kolicino eksperimentalnih podatkov, ki kazejo, da je genom dinamicen, hiearhicno organiziran in kompleksno integriran sistem za shranjevanje inobdelovanje informacij. Dinamicno ravnotezje med stabilnostjo in spremenljivostjo DNK zapisaje nujno za pravilno funkcioniranje organizma. Poleg stevilnih DNK popravljalnih proteinov in DNK varovalnih mehanizmov, imajo organizmi tudi biokemicne sisteme, sposobne spreminjanja DNK informacije. Eden najbolj polemicnih in hkrati najbolj poucnihje fenomen imenovan adaptivna mutacija. Najin namenje pregledati dognanja o adaptivni mutaciji pri prokariontih in pokazati, da je nadgradnja togega neodarvinisticnega pogleda na izvor genetskih variacij, nujno potrebna