Diferenzas entre revisións de «ADN recombinante»

 
== Propiedades dos organismos que conteñen ADN recombinante ==
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In most cases, organisms containing recombinant DNA have apparently normal [[phenotype]]s. That is, their appearance, behavior and metabolism are usually unchanged, and the only way to demonstrate the presence of recombinant sequences is to examine the DNA itself, typically using a polymerase chain reaction (PCR) test.<ref name="isbn1-4051-1121-6">{{cite book |author=Brown, Terry |title=Gene Cloning and DNA Analysis: an Introduction |publisher=Blackwell Pub |location=Cambridge, MA |year=2006 |pages= |isbn=978-1-4051-1121-8 |oclc= |doi= }}</ref> Significant exceptions exist, and are discussed below.
 
InNa mostmaioría casesdos casos, organismsos containingorganismos recombinantque DNAconteñen haveADN apparentlyrecombinante normalteñen aparentemente [[phenotypefenotipo]]s normais. ThatÉ isdicir, theira appearancesúa aparencia, behaviorcomportamento ande metabolism[[metabolismo]] arenon usuallyson unchanged,normalmente andcambiados thee onlyo wayúnico tomodo demonstratede thedemostrar presencea ofpresenza recombinantde sequencessecuencias isrecombianntes toé examineexaminar theo DNApropio itselfADN, typicallynormalmente usingusando aun polymerasetest chainde reaction ([[PCR) test]].<ref name="isbn1-4051-1121-6">{{cite book |author=Brown, Terry |title=Gene Cloning and DNA Analysis: an Introduction |publisher=Blackwell Pub |location=Cambridge, MA |year=2006 |pages= |isbn=978-1-4051-1121-8 |oclc= |doi= }}</ref> SignificantHai exceptionstamén existexcepcións significativas, andque se arediscuten discussedmáis belowabaixo.
If the rDNA sequences encode a gene that is expressed, then the presence of RNA and/or protein products of the recombinant gene can be detected, typically using [[RT-PCR]] or [[Western blot|western hybridization]] methods.<ref name="isbn1-4051-1121-6"/> Gross phenotypic changes are not the norm, unless the recombinant gene has been chosen and modified so as to generate biological activity in the host organism.<ref name="pmid|10634784">{{Cite journal
 
Se as secuencias de ADN recombinante codifican un xene que se expresa, entón pode detectarse a presenza de ARN e/ou produtos proteicos do xene recombinante, xeralmente usando as técnicas da [[RT-PCR]] ou do [[western blot]].<ref name="isbn1-4051-1121-6"/> Os cambios fenotípicos grandes non son o normal, a non sder que o xene recombinante fose elixido e modificado para xerar unha actividade biolóxica no organismo hóspede.<ref name="pmid|10634784">{{Cite journal
| last1 = Ye | first1 = X.
| last2 = Al-Babili | first2 = S.
| pmid = 10634784 | doi=10.1126/science.287.5451.303
| bibcode = 2000Sci...287..303Y
}}</ref> Os fenotipos adicionais que se poden encontrar son toxicidade no organismo hóspede inducida polo produto recombinante, especialmente se este é sobreexpresado ou expresado en células ou tecidos inapropiados.
}}</ref> Additional phenotypes that are encountered include toxicity to the host organism induced by the recombinant gene product, especially if it is [[Protein expression (biotechnology)|over-expressed]] or expressed within inappropriate cells or tissues.
 
InNalgúns some casescasos, recombinanto DNAADN canrecombinante havepode deleteriouster effectsefectos evendeletéreos ifincluso itse isnon noté expressedexpresado. OneUn mechanismmecanismo bypolo whichcal thispode happensocorrer isisto é a [[InsertionInserción (geneticsxenética)|insertionalinactivación inactivationinseccional]], inna whichcal theo rDNAADN becomesrecombinante insertedqueda intoinserido anun hostxene cell'sda gene.célula Inhóspede. someNalgúns casescasos, researcherspode useutilizarse thiseste phenomenonfenómeno topara facer un "[[Gene knockout|knock outde xenes]]" genespara todeterminar determinea theirsúa biologicalfunción functionbiolóxica ande importanceimportancia.<ref name="pmid1591000">{{Cite journal
| last1 = Koller | first1 = B. H.
| last2 = Smithies | first2 = O.
| pmid = 1591000
| pmc =
}}</ref> Outro mecanismo polo cal a inserción do ADN recombinante no ADn cromosómico pode afectar á expresión xénica é pola inactivación inapropiada de xenes da célula hóspede que previamente non se expresaban. Isto pode acontecer, por exemplo, cando un fragmento de ADN recombinante que contén un promotor activo queda localizado pretotdun xene da célula hóspede previamente silencioso ou cando un xene da célula hóspede que funciona restrinxindo a expresión xénica sofre unha inactivación insercional polo ADN recombinante.
}}</ref> Another mechanism by which rDNA insertion into chromosomal DNA can affect gene expression is by inappropriate activation of previously unexpressed host cell genes. This can happen, for example, when a recombinant DNA fragment containing an active promoter becomes located next to a previously silent host cell gene, or when a host cell gene that functions to restrain gene expression undergoes insertional inactivation by recombinant DNA.
 
== Usos ==
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Recombinant DNA is widely used in [[biotechnology]], [[medicine]] and [[research]]. Today, recombinant proteins and other products that result from the use of DNA technology are found in essentially every western pharmacy, physician or veterinarian office, medical testing laboratory, and biological research laboratory. In addition, organisms that have been manipulated using recombinant DNA technology, as well as products derived from those organisms, have found their way into many farms, [[Genetically modified food|supermarkets]], [[Humulin|home medicine cabinets]], and even pet shops, such as those that sell [[GloFish]] and other [[genetically modified animal]]s.
 
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