Gomis-Ruth, F. X., Moncalian, G., Perez-Luque, R., Gonzalez, A., Cabezon, E., de la Cruz, F. & Coll, M. 2001. The bacterial conjugation protein TrwB resembles ring helicases and F1- ATPase. Nature 409: 637-641. Hawksworth, D. L., Kirk, P.M., Sutton, B.C. & Pegler, D.N. 1995. Ainsworth & Bisby’s Dictionary of the Fungi. CABI, 616 pp. Holst-Jensen, A., Vaage, M., Schumacher, T. & Johansen, S. 1999. Structural characteristics and possible horizontal transfer of group I introns between closely related plant pathogenic fungi. Molecular Biology and Evolution 16: 114-126. Ito, Y. & Hirano, T. 1999. A group I intron in the 18S ribosomal DNA from the parasitic fungus Isaria japonica. Journal of Molecular Evolution 48: 337-340. Jamrt-Vierny, C., Boulay, J. & Briand, J-F. 1997. Contribution of various classes of defective mitochondrial DNA molecules to senescence in Podospora anserina. Current Genetics 31: 171-178. Jazwinski, S.M. 1996
intronid ja eksonid. Pärast transkriptsiooni lõigatakse intronid välja ja ainult kokkuliidetud eksonid moodustavad mRNA , mille alusel sünteesitakse valk. Kui tahame bakterisse geeni viia, siis peame selle mRNA alusel tegema DNA - õnneks on avastatud pöördtranskriptaas, mis selle töö ära teeb. Nüüd teeb bakter sama valku, mis see geen inimese rakuski teeb. RNA trans- kript http://faculty.ircc.edu/faculty/tfischer/images/introns-exons.jpg Bakterid toodavad inimese valke alates 1978.aastast Esimene oli insuliin. Inimese kasvuhormoon Erütropoietiin aneemia raviks Interferoon, mis reguleerib immuunsüsteemi Vere hüübimisfaktorid Difteeria ja teetanuse vaktsiin Pärmseened teevad B-hepatiidi vaktsiini Putukarakud toodavad papilloomi vaktsiini Transgeensed loomad Esimene transgeenne hiir saadi 1981.a.: roti kasvuhormooniga kasvas 2 X suuremaks. Miks hiiri kasutatakse kõige rohkem?
vajab splaisinguks vaba guaniini, Arhebakterite intronid esinevad tRNA ja rRNA geenides. Konserveerunud struktuur ning self-splaising puuduvad. Esinevad valgulised splaisingufaktorid, puuduvad trans-toimivad RNA molekulid. Intronite päritolu: Intronid esimesena (intron first hypothesis) postuleerib, et intronid ja RNA splaising on jäänukid RNA maailmast ja eelnesid prokarüootsetele introniteta geenidele, mis kaotasid splaisingu võites efektiivse geeniekspressiooni, Intronid teisena (introns late hypothesis) väidab, et introniteta (prokarüootne) geen on ürgne ja intronite insertsioon on hilisem näht, mis kestab siiani. Intronid on tekkinud täiustamaks funktsionaalset mitmekesisust. Intronite asukoha konserveerumine globiini superperekonnas viitab ürgsele intronite insertsioonidele (algselt kaks intronit ~800 milj. a. tagasi). 23. Homoloogid, ortoloogid ja paraloogid. Homoloogid on väga sarnase järjestusega liigisisesed geenid ( ja globiinid)
This complex cleaves the RNA between the polyadenylation sequence and the GU-rich sequence at the cleavage site marked by the (5'- CA-3') sequences. Poly(A) polymerase then adds about 200 adenine units to the new 3' end of the RNA molecule using ATP as a precursor. As the poly(A) tail is synthesised, it binds multiple copies of poly(A) binding protein, which protects the 3'end from ribonuclease digestion.[4] [edit]Splicing Main article: RNA splicing RNA splicing is the process by which introns, regions of RNA that do not code for protein, are removed from the pre-mRNA and the remaining exons connected to re-form a single continuous molecule. Although most RNA splicing occurs after the complete synthesis and end-capping of the pre-mRNA, transcripts with many exons can be spliced co-transcriptionally.[5] The splicing reaction is catalyzed by a large protein complex called the spliceosome assembled from proteins and small nuclear
notable is in the RNA interference pathway, where it interferes with the expression of specific genes with complementary nucleotide sequence. The process of RNA interference can be moderated by either siRNA or miRNA, but there are subtle differences between the two.. siRNA is considered exogenous double-stranded RNA that is taken up by cells, or enters via vectors like viruses, while miRNA is single stranded and comes from endogenous (made inside the cell) non-coding RNA, found within the introns of larger RNA molecules. Another difference is that, in animals, siRNA typically binds perfectly to its mRNA target, a perfect match to the sequence, whereas miRNA can inhibit translation of many different mRNA sequences because its pairing is imperfect. In plants, miRNA tends to have a more perfectly complimentary sequence which induces mRNA cleavage as opposed to just repression of translation. RNA interferents (RNAi) on süsteem elavates rakkudes, mis osaleb geeniaktiivsuste määramisel.
This complex cleaves the RNA between the polyadenylation sequence and the GU-rich sequence at the cleavage site marked by the (5'- CA-3') sequences. Poly(A) polymerase then adds about 200 adenine units to the new 3' end of the RNA molecule using ATP as a precursor. As the poly(A) tail is synthesised, it binds multiple copies of poly(A) binding protein, which protects the 3'end from ribonuclease digestion.[4] [edit]Splicing Main article: RNA splicing RNA splicing is the process by which introns, regions of RNA that do not code for protein, are removed from the pre-mRNA and the remaining exons connected to re-form a single continuous molecule. Although most RNA splicing occurs after the complete synthesis and end-capping of the pre-mRNA, transcripts with many exons can be spliced co-transcriptionally.[5] The splicing reaction is catalyzed by a large protein complex called the spliceosome assembled from proteins and small nuclear
sünteesiks, modifikatsiooniks ja geenide avaldumise regulatsiooniks. RNA-protsessing (ingl. RNA processing)- RNA transkriptsioonijärgsel ümberkorraldamisel toimuv translatsioonieelsest RNA-st spetsiifiliste järjestuse kõrvaldamine ning transkripti mõlema otsa modifikatsioon: pre-mRNA 5´-otsa lisatakse 7- metüülguanosiinmüts ja 3´-otsa polü-A järjestus. 17. Intronid ja geeni splaissing intronid (ingl. Introns)- Eukarüootsete geenide DNA-aluste vahejärjestused, mida ei esine töödeldud RNA-transkriptis, kuivõrd nad lõigatakse splaissingul primaarsest RNA-transkriptist välja. splaissing e. kokkupõime (ingl. Splicing)- Protsess, mille käigus RNA-st elimineeritakse eksonite vahele jäävad intronite järjestused ja eksonite järjestused seotakse kovalentselt. 18. Valgusüntees rakkudes, tuum ja tsütoplasma Valgusüntees ehk valgu biosüntees on valkude moodustamise
9 AVP; e.g. increased mineral nutrients increases susceptibility of corals to disease, increased numbers of anaerobic species, ref to heavy metal toxicity 4 max [4] 80. humans are eukaryotes / Escherichia coli is a prokaryote; humans / eukaryotes have (accept ora) larger, proteins / genes; introns; ‘junk’ DNA / non-coding DNA; repeating sequences; centromeres / telomeres; fossil genes; E. coli cell much smaller; ora selection for, less waste of space / more compact genome; 2 max [2] 81. (i) semi-conservative replication; DNA, polymerase / helicase;
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