Term
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Definition
| a gene that is introduced into an organism |
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Term
| Does human gene therapy refer to germline or non-germline cells? |
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Definition
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Term
| What are some common vehicles for delivering transgenes? |
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Definition
-viruses (adenovirus, retrovirus, herpesvirus)
-liposome |
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Term
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Definition
| lipid-coated artificially created vesicles which are fused with cell membranes to introduce a transgene |
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Term
| What is a risk in the introduction of a virus into an existing genome? |
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Definition
-no control over how the introduced virus & genetic information will be incorporated
-may interfere or mutate highly conserved genes, causing cancer among other issues |
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Term
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Definition
Adenosine deaminase-deficient Severe Combined Immunodeficiency Disease
-lack of functional B & T cells (no immune response) |
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Term
| Describe the steps involved in the gene therapy treatment of ADA-SCID |
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Definition
1. Isolate bone marrow stem cells from patient
2. Infect bone marrow with IL2RyC+ retroviral vector
3. Grow cells in culture & verify expression of the gene
4. Infuse stem cell transgene into patient
5. Success means that the IL2RyC+ protein will restore production of functional WBCs |
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Term
| What is the common use of recombinant protein production technology? |
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Definition
to produce pharmaceuticals
e.g. human insulin, human growth hormone |
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Term
| What are some common uses of transgenic animal? |
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Definition
-study gene function
-produce new products
-model systems for human diseases or crop plants |
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Term
True or False
The generation of transgenic animals & transgenic plants follow similar processes |
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Definition
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Term
| What does the oocyte contribute to zygote formation? The sperm? |
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Definition
Oocyte
-haploid genome
-proteins & maternal RNA
-nutrients
Sperm
-haploid genome |
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Term
| At what stage is the fate of cells determined in animal development? |
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Definition
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Term
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Definition
| cell division & migration after the blastula stage |
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Term
| What are the characteristics of model organisms? |
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Definition
-short life cycles
-small adult size
-readily available
-easily accessible for genetic/other experimental manipulations |
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Term
| Why can we use fruit flies to study genetic mutations in other animals? |
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Definition
| homologous genes are genes which share common ancestry; many Drosophila genes are homologous to those in other species |
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Term
| What are the two major classes of genes controlling drosophila embryonic development? |
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Definition
Maternal-Effect genes
-effect the next generation only
-affect egg formation
Zygotic Genes
-biparental genes
-activated by maternal-effect genes, after fertilization
-embryonic mutations are lethal |
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Term
| What determines bilateral symmetry axes, and when? |
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Definition
-RNAs deposited during oogenesis, established very early in development
-maternal effect genes! |
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Term
| Steps of establishing an anterior-posterior axis in Drosophila in relation to the hunchback, bicoid, caudal & nanos genes |
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Definition
1. RNA for all 4 genes is deposited into the oocyte.
2. Hunchback & caudal are distributed uniformly, bicoid at anterior end and nanos at posterior.
3. Local translation of bicoid & nanos & diffusion of the proteins produced to form gradients.
4. Bicoid prevents translation of caudal RNA in anterior end, nanos prevents hunchback in posterior
5. Hunchback translated at anterior end, caudal is translated in posterior end
6. Hunchback & bicoid proteins act as transcription factors to regulate differentiation of anterior region, caudal proteins regulate differentiation of posterior region. |
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Term
| What is the importance of gradients of maternal-effect gene products? |
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Definition
| provides cells with positional information along the anterior/posterior axis during embryo development |
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Term
| Is body segmentation controlled by zygotic or maternal-effect genes? |
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Definition
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Term
| What are gap genes, what region of the body do they affect and how are they controlled? |
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Definition
Gap Genes
-zygotic genes
-affect a large region of the body
-encode transcription factors with zinc-finger motif
-controlled by maternal-effect genes |
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Term
| If a drosophila has multiple continuous segments of their body missing, what type of gene is likely mutated? |
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Definition
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Term
| If a drosophila is missing half of the parasegments of its body, what type of gene is likely mutated? |
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Definition
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Term
| If a drosophila has one half of a segment of its body replaced by the other half of the same segment, what type of gene is likely mutated? |
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Definition
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Term
| If a drosophila has one segment of their body transformed into another, what type of gene is likely mutated? |
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Definition
| a selector gene/homeotic gene |
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Term
| What are pair-rule genes, what region of the body do they affect and how are they controlled? |
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Definition
Pair-Rule genes
-zygotic genes
-affect smaller domains of the body, alternating every other segment
-encode transcription factors with helix-turn-helix motif
-controlled by gap genes |
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Term
| What are selector/homeostatic genes, what region of the body do they affect and how are they controlled? |
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Definition
-determine adult structures to be formed by each segment
-encode transcription factors with a homeodomain (helix-turn-helix)
-controlled by segmentation genes |
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Term
| What are segment polarity genes, what region of the body do they affect and how are they controlled? |
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Definition
Segment Polarity Genes
-affect small domains within a segment
-controlled by pair-rule genes |
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Term
| Describe the cascade steps of gene expression which produces segmentation in Drosophila embryos |
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Definition
1. Maternal effect genes establish anterior/posteior polarity
2. Gap genes subdivide embryo into broad zones
3. Pair-rule genes are expressed in 14 bands along A/P axis
4. Segment-polarity genes are expressed in each subsegment along the A/P axis
5. Homeotic genes are expressed in specific regions along the A/P axis |
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Term
| What happens if the Sev gene of drosophila is mutated? (sevenless) |
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Definition
| R7 photoreceptor in the eye differentiates into cone cells instead of neurons |
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Term
| What is the relationship between R7 & R8 photoreceptors, to correct a 'sev' mutation? |
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Definition
| -Sev gene encodes a receptor which can only be activated by binding to a ligand on R8 -R8 signal is relayed into R7 nucleus, initiating a cascade of gene expression/repression -R7 differentiates into a neuron (photoreceptor cell) |
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Term
| Explain colinearity, using insect HOM genes and vertebrate Hox genes as an example |
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Definition
| -various HOM & Hox genes are positioned on a chromosome in order of when & were they will be expressed in the body |
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Term
| What are the steps involved in generating transgenic mice by microinjecting DNA into fertilized eggs? |
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Definition
1. Inject DNA into nucleus of a zygote
2. Implant zygote into a pregnant mouse
3. Examine offspring for presence of the gene your injected to ID the transgenic mice |
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Term
| What are the steps involved in generating transgenic mice by embryonic stem cell technology? |
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Definition
1. Mate true-breeding dark-coloured mice & obtain embryos at blastocyst stage
2. Culture embryonic stem cells from the blastocyst
3. Swamp the endogenous gene with the transgene you want to introduce, with a marker so you can identify it.
4. Inject the transfectd ES cell into blastocyst from light-coloured parents
5. Implant the blastocyst in a pseudopregnant female
6. Mate chimeric offspring from this female to a light-coloured mouse
7. Examine DNA from dark offspring of this final mating for the DNA marker sequence you inserted (these will be transgenic) |
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Term
| What are the genetic advantages of the EnvironPig? |
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Definition
| -genetically modified to secrete phytase, which digests plant phytate phosphorous & will reduce environmental PO4(3-) pollution from pigs' feces |
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Term
| What does 'totipotent' mean? |
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Definition
| An entire organism can be regenerated from a single somatic cell |
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Term
| What is a Ti plasmid? What are its components? |
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Definition
Tumour-inducing Plasmid, found in soil bacteria
T-DNA: transposable element that carries genes which cause plant tumours
Virulence region: carries genes which integrate T-DNA into plant genome |
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Term
| How can you produce transgenic plants using a Ti plasmid? |
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Definition
1. Isolate the genetic sequence you want to introduce & plasmid from a bacterium
2. Insert this gene into the Ti plasmid
3. Insert recombinant Ti plasmid back into the bacterium
4. Introduce bacterium to soil of the plant you want to affect
5. Bacterium will transfer the Ti plasmid into plant chromosome & translation of the inserted genes will occur |
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Term
| What are some concerns about genetically modified foods? |
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Definition
-safety to human health, development of allergies
-increased herbicide use on herbicide-resistant crops
-reduced biodiversity
-accidental introduction of the transgene into other related species in the ecosystem |
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Term
| What is The Golden Rice Project? |
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Definition
| -development of rice which produces beta-carotene, a precursor of Vit A, to address a global Vit A deficiency problem |
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Term
| What is Nuclear Transfer? |
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Definition
Artificial construction of a zygote
-removing a nucleus from an egg & inserting a nucleus from an adult cell |
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Term
| What are some challenges of epigenetic reprogramming? |
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Definition
-genomic imprinting
-inactivation of X chromosomes
-maintenance of telomeres (preventing DNA degradation) |
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Term
| What is the master gene of eye development? |
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Definition
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Term
True or False
Expression of the mouse Small Eye gene will cause formation of extra eyes in Drosophila |
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Definition
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Term
| Is establishment of bilateral axes of symmetry controlled by zygotic or maternal effect genes? |
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Definition
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