ISBN-13: 9783642020049 / Angielski / Twarda / 2009 / 202 str.
ISBN-13: 9783642020049 / Angielski / Twarda / 2009 / 202 str.
It will be some time beforewe see Relax, there s nothing wrong with the slime, protoplasm, &c. generating transpositionpaper. People aren t a new animal. ButI have long readyforthisyet. Istopped publishing regretted that I truckled to public in refereed journals in 1965 because opinion, andusedthePentateuchal therewas nointerest in themaize term of creation, by which I really controlling elements. meant appeared by some wholly Barbara McClintockto Mel Green, unknownprocess. It is mere rubbish, 1969 thinking at presentof theorigin of life; onemight as well think of the originof matter. Charles Darwin to James D. Hooker, March29, 1863 Sometimes my students and others have asked me: what was ?rst in evo- tion retroviruses or retrotransposons? Since HowardTemin proposed that retrovirusesevolvedfromretrotransposons(Temin1980;Teminetal. 1995)the other alternative that retroviruses emerged ?rst and were the predecessors of LTR-retrotransposons has since been a controversial issue (Terzian et al., this BOOK). While DNA-transposons could not have existed in an ancestral R- world by de?nition, sure enough, some arguments de?nitely point towards apre-DNAworldscenarioinwhichretroelementswerethedirectdescendants of the earliest replicators representing the emergence of life. First, these rep- cators likely catalyzed their own or other s replication cycles via the catalytic properties of RNA molecules. After translation had emerged some replicators possibly encoded an RNA polymerase ?rst. This later evolved into reverse transcriptase(RT), i. e. themostprominentkey-factoratthetransitionintothe DNA world. Simultaneously, replicators could also have encoded membrane protein-genessuchastheenvgeneofrecentDNA-proviruses. Membraneswere likely present muchearlier as prebioticoily ?lms that supported theevolution of a prebiotic-protometabolism (Dyson 1999; Grif?ths 2007)."