Lecture 48. Complex Genetic Variation Flashcards
What is the main source of genetic variation used for research in experimental genetic models?
Artificial Mutation
What is the main resource for translational genetics?
Natural Variation
What are the names of the unusual traits in a species?
Discrete traits
What is complete dominance?
Maximum expression in both AA and Aa with no expression in aa
What is incomplete dominance?
Maximum expression in AA, intermediate expression in Aa and no expression in aa
What is over dominance?
Intermediate expression in AA, maximum expression in Aa and no expression in aa
What is full penetrance?
Maximum expression in both AA and Aa with no expression in aa
What is partial penetrance?
Medium expression in AA, weak expression in Aa and no expression in aa
What is the cause of primordial dwarfism?
Pericentrin gene mutations (PCNT)
Are there any treatments for primordial dwarfism?
No
What is the cause of genetic hypopituitary dwarfism?
Mutation in one of several genes (GHRHR, GH1)
Are there any treatments for genetic hypopituitary dwarfism?
Yes, growth hormone therapy (somatotropin)
What is the human growth hormone equivalent in plants?
Gibberellic acid (GA)
How do dwarf mutants react to GA?
Some dwarf mutants are GA-responsive whilst others are not
What is redundancy?
Duplicate genes that provide the same function
What is the prediction if two pea varieties are bred together that share the same phenotype for flower colour and the first and second generation are all purple?
Both pea varieties share the same gene for flower colour
What are complementary genes?
The phenotype depends on both genes being functional (e.g different steps in same biochemical pathway)
What do Mendelian factors form the basis of?
The basis of quantitative (polygenic) traits
What are the two methods used to map genes that underlie a phenotype on the basis of correlation with DNA sequence variation?
Linkage mapping population
Association mapping
What is linkage mapping population?
Progeny derived from a controlled cross of known parents (chosen because they exhibit contrasting phenotypes and are polymorphic in many genome-wide DNA markers)
What are the pros of recombinant inbred mapping population?
No questions of dominance
Immortal lines
Powerful data accumulation
Reproducibility
GxE experiment possible
Inter-mating inbreds, to test genetic models
What are the cons of recombinant inbred mapping population?
Finite resource
What does LOD stand for?
Logarithm Of the Odds
What is an LOD score?
A statistical test for linkage
