Applied Molecular Biology Flashcards
Mutations resulting in a change of restriction sites in a gene can be used to perform pedigree analysis of individuals. In other words, the same gene of two individuals may be cleaved differently by a given restriction enzyme and result in gene fragments of different size. This type of difference is called what?
Restriction Fragment Length Polymorphism (RFLP)
If RFLP occurs as a result of mutation in DNA coding for an essential protein, the RFLP can be used to do what? If it occurs in gene loci that have no known function or not related to disease, it can be used to do what?
diagnose the disease; identify the individual (forensic pathology)
What is the molecular basis for Sickle Cell Anemia?
substitution of T and A in the template strand of the sixth codon for beta-globulin changes the codon from glutamic acid to valine
What physical properties of hemoglobin are effected in SCA?
at reduced oxygen tension, the hemoglobin precipitates
What is the basis of detection for SCA?
loss of restriction enzyme site (MstII) - when this gene is amplified (PCR) and subjected to treatment with MsII, the pieces of DNA generated are different from that in a normal individual
If the mutation is known, one can rapidly determine genotype of patient by hybridization of ____ ____ oligonucleotides (labeled with 32P) to PCR amplified region of gene in question
alley specific oligonucleotides (ASOs)
The basis of DNA finger printing is RFLP. Because some mutations some segments of DNAs from different individuals contain different restriction enzyme sites and thus these segments would yield what?
different sized fragments when digested with enzymes
Polymorphism in angiotensinogen is being used to predict ____ in cardiac patients
hypertension
Certain sections of DNA are known to be hypervariable. What does this mean?
no two individuals (excluding identical twins) possess the exact same restriction sites in this region - can be used to identify individuals
“Gene chips” or ____ are revolutionary new technology for analyzing ____ _____
microarrays; gene expression
In regards to gene chips, hundreds of unique gene fragments (DNA) are fixed to glass slides by robotic work stations used in computer chip assembly. RNA isolated form cells or tissues can be converted to ____ with reverse transcriptase
cDNA
note: synthesis occurs with incorporation of fluorescently labeled nucleotides
In regards to gene chips, _____ of fluorescently labeled cDNA to DNA ‘spots’ on the chip - each of which corresponds to a unique gene-allows quantitative measurement of message
hybridization
In regards to gene chips, if two different cell populations are carried through the procedure and each cDNA pool is labeled with a different florescent nucleotide, then a differential expression level will result as the computer sums data analyzed in two different channels. True or false?
true
What are the major problems of gene therapy?
efficiency of integration and expression of therapeutic genes
In regards to gene therapy, in many cases only about 5-10% of normal expression may be enough to bring about a correction of the biochemical deficiency. True or false?
true
There are both viral and non-viral gene delivery strategies. The non-viral suffer from low efficiency of ____ into cells. The viral have problems like inducing an ___ ____ which will nullify the therapy or cause cancer
delivery; immune response
What is the advantage and disadvantage of the retrovirus method of gene delivery?
advantage: stable chromosomal integration; easy to produce
disadvantage: transduces dividing cells only; risk of insertional mutagenesis
What is the advantage and disadvantage of the adenovirus method of gene delivery?
advantage: high titers achievable; easy to produce
disadvantage: transient expression induces immune response
What is the advantage and disadvantage of the adeno-associated viruses method of gene delivery?
advantage: nonpathogenic; broad target range; site-specific integration
disadvantage: difficult to produce; carries only small genes
What is the advantage and disadvantage of the transfection method of gene delivery?
advantage: easy to prepare
disadvantage: no well documented role in vivo