Professor Moon Lecture 7+8 Flashcards
What is a dominant mutation?
When a single copy of the mutation produces a phenotype (disease) despite having a wild type copy of the gene
-just one copy of the gene is enough to produce the mutation
What is a haploinsufficency, what is it an example of?
-when one single copy of the gene is not enough to carry out the function
-its an example of a dominant mutation
What is a dominant negative, what is it an example of?
it is an example of a dominant mutation and it is when the mutant gene can adversly affect the wildtype gene when in the same cell
What role does TBX1 play as a transcription factor?
What is an example of disease that occurs with a TBX1 mutation, what type of mutation is this?
ROle of TBX1, its important for the formation of tissues and organs during embryonic develeopment
2.patients with DIGeorge syndrome wihtout the 22q11.2 deltion have a TBX1 heteroygous mutation (only one copy was mutated)
3. haploinsuffient mutation
Why does a mutation in the p53 alelle cause cancer
this is because it functions as a dominant negative mutation, and it is a transcription factor that binds DNA as a homotatramer (4 identical p53 subunits that come together to bind DNA)
what is incomlete or partial dominance
it is when the heterozygous form the gene is a mix between the dominant and recessive phenotype
what is codomaince and what is an example of it?
when both alleles are expressed/detected
for example, there are 3 alleles for blood however A and B blood type expresses both A and B properties
What does hemoglobin encode for and what type of mutation can occur when there is sickle cell anemia?
Hb gene encodes for beta-globin
-and the mutation that occurs is incomplete dominance 9type of codominance) bc if the genes are heterozygous you can get something in between sickle/normal
What is a recessive lethal allele?
when a homozygous mutation causes lethality in an animal, either recessive or dominant mutations (they are haplosufficient genes)
What are conditional alleles?
they are temperature controlled phenotypes when the animals are produced at higher or lower temperatures (permissive temp)
