Exam 18: Manipulating the Genomes of Eukaryotes

To generate a knockin mouse, a scientist introduces to ES cells a construct with a mutant exon and within an adjacent intron, loxP sites flanking a neomycin resistance gene.What event will occur next?

To create a knockout mouse, after introducing to ES cells a DNA construct in which a specific gene is mutagenized by the insertion of a drug resistance marker, the cells

After exposure to Agrobacterium tumefaciens bacteria containing both a recombinant T-DNA vector and a helper plasmid, new plants can be grown from single cells in the presence of herbicide.Without the herbicide,

Pharming refers to the use of transgenic animals and plants to produce protein drugs, such as

Recombinant Ti plasmids allow for

To create transgenic mice, DNA is injected into

How can transgenic organisms be used to identify transcriptional enhancers?

Transgenic organisms are used to clarify which gene may be responsible for a mutant phenotype because

Although bacteria can be used to produce proteins for therapeutic uses, what can be a disadvantage to using a prokaryotic system?

A researcher has a laboratory strain of flies that have loss-of-function mutations in both gene X and white.These flies are used as hosts for P element transformation: Embryos of the double mutant strain are injected with two plasmids, one containing a wild-type copy of the white gene (w⁺)and a wild-type copy of gene X, side-by-side within P element inverted repeats, and the other plasmid containing only the P element transposase gene.Transgenic offspring of the injected flies will

A scientist wants to determine whether a mutant phenotype is due to the loss of gene C or gene D, which are both deleted in a mutant fly with abnormal eyes.Mutant flies with transgenic gene C have wild-type eyes, whereas mutant flies with transgenic gene D have abnormal eyes.What can be concluded from these results?

Fragile X syndrome is a human disease caused by a trinucleotide repeat expansion that results in loss-of-function of the FMR1 gene on the X chromosome.An animal model with most features of this syndrome could be created by

Why are conditional knockout animals desirable?

The disease Leber congenital amaurosis (LCA), caused by loss-of-function mutation of a gene called RPE65, has been treated with gene therapy by injecting recombinant AAV vectors containing a normal copy of the RPE65 gene into their retinal epithelial cells.Patients receiving this therapy

A trait unique to embryonic stem cells that makes them useful for generating knockout animals is that they

A scientist might create a conditional knockout of a mouse gene when

Using the CRISPR/Cas9 system, a genetically-engineered sgRNA complementary to a target site in the genome binds to Cas9 endonuclease.A mutation can occur at this site when

What is a possible disadvantage of using genetically modified crops?

What is one problem associated with using retroviruses as human gene therapy vectors?

CRISPR sequences occur naturally as