Mutation: complementation, gene structure and gene function Flashcards
(9 cards)
What are the two different types of recessive loss of function gene mutations as defined by Muller.
Null mutations and hypomorphic mutations.
What is a null mutation?
When a homozygous mutant/mutant has the same phenotype as a mutant/deletion. Thus, the mutant allele has no gene function.
What defines a hypomorph?
When a homozygous mutant/mutant has a phenotype more similar to the wildtype than a mutant/deletion. Thus, the mutant allele has reduced gene function.
What is the name for a dominant loss of function mutation as defined by Muller?
A haploinsufficient mutant.
What defines a haploinsufficient mutant?
Mutant/wildtype has a dominant phenotype and this phenotype is the same as deletion/wildtype. (one wildtype copy is not enough for a normal phenotype)
What are the three types of dominant mutations that alter gene function?
Antimorphic mutations, hypermorphic mutations, and neomorphic mutations.
What defines an antimorphic mutant?
The mutant/wildtype has a more severe mutant phenotype than mutant/wildtype with an additional wildtype allele. Thus, the mutant allle antagonizes the wildtype allele.
What defines a hypermorphic mutation?
Mutant/wildtype has a weaker phenotype than Mutant/ 2 copies of the wildtype. Thus, the mutant allele has increased wildtype activity.
What defines a neomorphic mutation?
Mutant/wildtype is the same as mutant/2 copies of the wildtype. Thus, the mutant allele has a novel function that differs from the wildtype and adding a duplication of the wildtype allele has no effect on phenotype.