Lecture 7 - Gathering Variability Flashcards
what happens when we run out of variation
you lose important characteristics and cannot keep selecting (because there is nothing to select for)
what is a gene pool
a collection of alleles in a species/population
what is a synthetic polyploid
species with multiple genomes
examples of induced mutations
- modified fatty acid profiles in oil crops
- herbicide tolerance
- dwarf barley
- floral mutations in ornamentals
mutations can come with ______
penalties
types of induced mutations
irradiation
chemical mutagens
example of a mutated crop variety
CDC maria glabrous canaryseed (first hairless canaryseed)
problems associated with induced mutations
- indiscriminate, multiple genome (need to be lucky to get desired trait)
- usually accompanied by negative effects
- need breeder to clean up phenotype
site-directed mutagenesis
target specific genes (or bases) for alterations
what knowledge must you have to use site directed mutagenesis
- knowledge of genomes
- knowledge of genes controlling trait of interest
knowledge of what changes might give rise new phenotypes
what does CRISPR do
introduces double stranded breaks into foreign DNA and generate genetic diversity
2 things CRISPR can do to genes
gene knockout
gene replacement/knockin
examples of CRISPR
- early flowering tomato that had photoperiod gene knocked out
-powdered mildew resistance in wheat
steps of using CRISPR
- need to know gene and desired sequence
- transformation of plant tissues with the construct
- genotyping to confirm presence of construct DNA
- pollen from edited plants crossed with wild type to confirm transmission abilty
should CRISPR based alterations to a plant be considered like GMOs
technically are not adding anything new and could be done with regular methods (though typically opinion based answer)
