Številne potencialne negativne učinke na okolje in zdravje živali se lahko z različnimi metodami zmanjša oz. prepreči. Potencialna varnostna tveganja se lahko zmanjša z izbiro ustreznih ekspresijskih platform, ki imajo sposobnost ustreznih post-translacijskih modifikacij in ne producirajo toksinov. Prenosu transgenov v okolje preko peloda se lahko izognemo z uporabo kloroplastne transformacije, kjer se transgen vstavi v kloroplastni genom, kloroplastna DNA pa se deduje maternalno, zato se transgen ne bo nahajal v pelodu (Guan in sod., 2013). Pobiranje listov gensko spremenjene rastline s pomočjo kloroplastne transformacije pred cvetenjem prepreči tudi ''uhajanje'' transgena v okolje preko semen (Shahid in Daniell, 2016). Smiselno je tudi uporabljati rastline, ki imajo možnost vegetativnega razmnoževanja, saj se s tem zmanjša tveganje za križanje z ne-transgenimi rastlinami na prostem (Liew in Hair-Bejo, 2015). Poleg tega se lahko določene rastline za pridobivanje cepiv goji tudi v rastlinjakih in drugih zaprtih prostorih in se s tem zmanjša možnost prenosa genskega materiala na ne-transgene rastline, lahko pa se aktivne komponente za cepiva pridobiva s pomočjo in vitro kultur.
Razvija se tudi nove napredne metode za zmanjšanje potencialnih negativnih vplivov na okolje, kot je npr. tehnika odstranjevanja eksogenega gena. Gre za posebno tehniko, pri kateri se v tarčne transgene rastline vstavi poseben gen pod kontrolo promotorja DNA regulatornega fragmenta. Vstavljeni posebni gen nato spontano odstrani eksogeni gen ob določenem času ali na določenem mestu v rastlini. Tako pelod, plodovi in semena transgenih rastlin ne vsebujejo transgena. S pomočjo te tehnike se lahko iz gensko spremenjenih rastlin po določeni razvojni fazi pridobiva ne-transgene rastline (Guan in sod., 2013).
7 ZAKLJUČEK
Kljub intenzivnim raziskavam, ki potekajo že več kot 20 let, veterinarska cepiva iz transgenih rastlin še vedno niso dosegla trga, vendar novi napredki na tem področju dajejo upanje, da se
18
bo to zgodilo že v bližji prihodnosti. Razvita tehnologija je učinkovita, količine sintetiziranih rekombinantnih proteinov so dovolj velike, stestiranih je bilo že veliko cepiv za zelo različne patogene, obstajajo nove tehnike za povečanje varnosti takšnih cepiv in regulatorni organi so končno pripravljeni sprejeti idejo cepiv, pridobljenih iz transgenih rastlin. Takšna veterinarska cepiva bi predvsem v živinorejski proizvodnji bistveno olajšala proces cepljenja in znižala stroške zaradi enostavnejšega shranjevanja in transporta cepiva, zaradi česar bi bila cepiva dostopnejša. To je še posebej pomembno za države v razvoju, kjer se trenutno živalske bolezni širijo veliko hitreje kot v razvitejših državah ravno zaradi vseh pomanjkljivosti cepiv, ki se trenutno uporabljajo za nadzor nad živalskimi boleznimi. Omejitev širjenja živalskih bolezni bi doprinesla tako k blaginji živalske kot tudi človeške populacije.
8 VIRI
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22 ZAHVALA
Iskreno se zahvaljujem mentorici izr. prof. dr. Zlati Luthar za pomoč pri izbiri tematike diplomske naloge, za prijaznost, stalno razpoložljivost in nasvete pri pisanju naloge.
Svoji družini in fantu, ki so me med pisanjem naloge spodbujali in mi svetovali, se iz srca zahvaljujem za podporo, ki mi jo vsakodnevno izkazujejo na vseh življenjskih področjih in verjamejo vame bolj kot jaz sama.
Zahvaljujem se tudi Brinu, moji antistresni bunkici, saj mi je med pisanjem naloge vedno delal družbo in bil moja moralna podpora v stresnih trenutkih.