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Biotechnology Exam 2
Transgenic-IVP
51
Agriculture
Undergraduate 4
10/20/2009

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Cards

Term
What are two hormones used in estrus synch?
Definition

PG

P4

GnRH

Term
When does oocyte activation occur
Definition
After sperm penetrates zona, before then oocyte was arrested in Metaphase II
Term
You would like to produce a transgenic animal which expresses a certain protein in its milk but not in other tissues. What would you include in the transgene to accomplish this goal?
Definition
tissue specific promoter (casein)
Term

If introns are included in a transgene it will not be expressed

 

T/F

Definition
false
Term
When transgenic animals are made by pronuclear injection not all transgenic animals will express the transgene. Why?
Definition
Because random position effects occur Means injection site is random and we don't know what the transgene will express
Term
What is the major advantage of producing transgenic animals by nuclear transfer?
Definition
You can select transgenic cells in culture and all animals should be transgenic
Term
What important transgenic tecnique (or type of experiment), is only possible with embryonic stem cells or nuclear transfer?
Definition
gene targeting (knock out or knock in)
Term
Name two examples of transgenic "bioreactor" systems
Definition

homologous recombination

nuclear transfer

Term
Give an example of potential transgenic animal application in agriculture.
Definition
phytase pigs (environmentally friendly)
Term
Give three methods for producing transgenic animals
Definition

nuclear transfer

pronuclear injection

embryonic stem cells

Term
What is a tumor inducing (Ti) plasmid? Where does it come from and what is it used for?
Definition
Comes from Agrobacterium tumeficans. Used to produce a tmor in the plant and at the site of injury transforms it to TDNA. At this site you can add the transgene of choice
Term
What is a "Ubiuitous" promoter? Give an example.
Definition
It's expressed in many tissues. CMV, PGK, housekeeping genes
Term
What is siRNA and how is it used?
Definition
Short hairpin RNA, used to regulate expression at the transcription level
Term
Define transgene
Definition
A gene that has been introduced into the genome of an organism that orginated from another source
Term
Define transgenic organism
Definition
A living organism that harbors an inserted functional gene in its germ line (gametes, passed on through them)
Term
Describe genomic gene structure
Definition
Preferred, not always practical. Exons, plus all introns. Best expression
Term
Describe cDNA gene structure
Definition
Exons only. most available. Low expression gives mixed results, message splicing important.
Term
Describe mini gene structure
Definition
Exons plus one or two introns. mixed results. better than cDNA
Term
What do enhancers do?
Definition
increase expression levels or tissue specificity. May be an intron. Several kb from promoter
Term
How can you control transgene expression?
Definition

High expression in many tissues

Expression in a specific (different) tissue

Gene switches

Promoters and/or enhancers

Term

List tissue specific promotors for:

 

milk 

muscle

liver

Definition

milk - casein

muscle - actin

liver - metallothioneine

Term
What age are the embryos for nuclear injection?
Definition

One cell inject into pronuclei

2-4 cell inject in nuclei

Term
What do insulators do?
Definition
Seperate. Very powerful.
Term
What are methods of producing transgenic animals?
Definition

1. nuclear injection

2. somatic cell nuclear transfer

3. embryonic stem cells

4. viral mediated gene transfer

5. sperm mediated gene transfer

6. spermatogonial transfer

7. particle bombardment

Term
How can you identify a transgenic animal?
Definition

1. DNA analysis

2. PCR

3. Southern Blot

Term
Problems with nuclear injection
Definition

1. Not all animals express the transgene

2. Random positioning effects

3. Establish a line from one or two animals, inbreeding unavoidable.

Term
List the 6 broad classes of GE animals as defined by the FDA
Definition

1.To enhance food quality or agronomic traits

2. To improve animal health

3. To produce products intended for human therapeutic use

4. To enrich or enhance the animals interactions with humans

5. To develop animal models for human diseases

6. To produce industrial or consumer products

Term
Knock out
Definition
gene inactivation
Term
knock in
Definition
gene replacement
Term
What is RNA interference? (RNAi)
Definition
targeting of specific mRNA to inhibit translation
Term
What are the primary steps to the Interference RNA mechanism
Definition

1.Long dsRNA is recognized in the cytoplasm by the ribonuclease III-like enzyme DICER.

        - DICER cleaves long dsRNA molecules to    21-23 nucleotide dsRNA molecules

         - these molecules are known as iRNA

2. iRNA molecules are then incorporated into RISC

        - the RISC-iRNA complex recognizes and targets mRNAs for degradation

        - effectively stops translation of the targeted mRNA, which is degraded

Term
What is RISC
Definition

RNA

Induced

Silencing

Complex

Term
What is siRNA
Definition

small interfering RNA

 

recently discovered, RISc associate, doesn't require DICER, 21-28 bp long, act as guide sequences for RISC

Term
What is an advantage of using particle bombardment in the production of transgenic plants?
Definition

Unlimited host range.

Not limited by ability to regenerate from single cells

Immature embryos from seeds will continue to develop

Transgenic plants selected

Term
What are the 6 genetically modified traits in plants?
Definition
  1. herbicide resistance
  2. insect resistance
  3. virus resistance
  4. altered oil content
  5. delayed fruit ripening
  6. pollen control
Term
What are two ways transgenic animals could pontentially be important in human medicine?
Definition

1. Disease models

2. production of drugs

3. Transplantation of tissue into humans

Term
Describe an example of gene targeting by homologous recombination.
Definition

Knock in or Knock out

Mouse embryonic stem cells

Somatic cells

Term

Spermatogonial transfer is the most common method of making transgenic animals.

 

T/F

Definition
false
Term
When transgenic animals are made by somatic cell nuclear transfer (cloning), how is the DNA (transgene) usually inserted into cells.
Definition
cloned DNA inserted into somatic or ES cells
Term
How do micro RNA regulate gene expression
Definition
Term
What is oocyte activation stimulated by?
Definition
fusion of sperm and oocyte plasma membranes causing an increase in free Ca in cytoplasm.
Term
Describe syngamy
Definition

fusion of parental genomes

pronuclear fusion

replication has occured in pronuclei

immediately into mitosis for divsion to 2 cell

Term
Describe maternal to zygotic transition
Definition

transition from using maternal mRNA to zygotic mRNA

 

8-16 cell bovine

4-8 pig

Term
Describe Compaction
Definition

Intracellular connections formed (gap jtns)

Outside cells = trophectoderm

Inside cells = ICM

 

Term
Describe Blastocyst Formation
Definition
  • Cell lineages established (ICM and trophectoderm)
  • Cavity formed
  • Pumping of fluid into cavity
  • Expansion and hatching
Term
Describe hatching
Definition
  • First oppurntunity for direct contact between embryonic cells and cells of the uterus
  • Maternal recognition of pregnancy.
Term
Reasons for ET
Definition

1. Increase # of offspring from selected female

2. Increase # of offspring from selected male

3. Import/Export *Driving force*

4. Treatment of infertility

5. Genectic testing of bulls

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