How do I make my own mutant?

Question 1

What is artificial selection?

Answer 1

• select individuals for the next generation
  OR
• selectively breed desired individuals

Question 2

What are the problems with artificial selection?

Answer 2

• don’t know what genes are associated
• because we are selecting on phenotype
• not always effective
• slow

Question 3

What are polygenic traits?

Answer 3

• characteristics encoded by genes at many loci

Question 4

What is marker-assisted artificial selection?

Answer 4

• genetic linkage between a marker (SNP) and your trait of interest
• can be within the gene itself or a nearby gene
• genotype and select individuals with that marker for artificial selection
• can’t predict what phenotype will be very early
• don’t have to wait for mature organisms
• a bit faster and a bit more effective

Question 5

What is cloning?

Answer 5

• the process of creating a genetically identical copy of a gene or organism
• can be a carbon copy but not entirely identical
• individuals may have different X inactivation

Question 6

What are the pros of cloning?

Answer 6

• desired traits
• organs for transplant
• endangered species

Question 7

What are the cons of cloning?

Answer 7

• low success rate
• imperfect
• telomeres, epigenetics, environment
• decreased biodiversity

Question 8

What is genetic engineering?

Answer 8

• manipulation of a gene in an organism to create the desired change
• GMO
• instead of altering gene, can also alter transcript processing
• RNA interference

Question 9

What are the basic steps in genetic engineering

Answer 9

• isolate gene
• make many copies
• extract gene production in bacteria or yeast
  OR
• extract DNA of interest and integrate into organism via transfection

Question 10

What is transfection?

Answer 10

• deliberately introducing nucleic acids into eukaryotic cells
• feeding
• embryo injection
• virus

Question 11

What are the pros of genetic engineering?

Answer 11

• significantly faster than artificial selection

- not limited by genetic changes naturally arising within a single species

Question 12

What are the cons of genetic engineering?

Answer 12

• may have unintended biological consequences

- potential for horizontal gene transfer to WT organisms

Question 13

What is double-stranded mRNA?

Answer 13

• normally single-stranded
• dsRNA gets targeted for degradation
• miRNA and siRNA
• protect against dsRNA viruses
• mechanism of gene regulation

Question 14

What is RNAi generally?

Answer 14

• start with dsRNA
• becomes guide RNA
• guide RNA binds to mRNA
• reduces or eliminates translation
• acts after transcription
• reversible

Question 15

How is miRNA made?

Answer 15

• transcription through an inverted repeat in DNA
• produce a primary miRNA
• now called pri-miRNA
• the pri-miRNA is cleaved to produce a short RNA with a hairpin
• dicer removes the terminal loop of the hairpin
• one strand of the miRNA combines with proteins to form on RNA-induced silencing complex (RISC)
• the strand with less stable 5’ strand becomes the guide strand
• passenger stand gets degraded
• RISC pairs with an mRNA and inhibits translation

Question 16

How is siRNA made?

Answer 16

• dsRNA may arise from RNA viruses or long hairpins
• dsRNA is cleaved by dicer to produce siRNA
• siRNA combines with proteins to form RISC
• RISC pairs with and cleaves mRNA
• leads to degradation

Question 17

What is some RNAi uses?

Answer 17

• only works in eukaryotes
• determine gene function
• good for developmentally lethal genes
• turn on and off in the same individual
• knock out transcripts in particular tissues
• potential use for gene therapy
• can remove just disease product