sickle cell malaria- example for epistasis?

[Isradoc1983]

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Hi
I was wondering whether sickle cell anemia gene on Hb that prevents malaria is an example of epistasis?
Can someone give me a good example for epistasis?

 

[jj2chemastray6]

Epistasis is where one gene masks the phenotypic effects of another gene.

I don't believe that is occurring with sickle cell anemia. Sickle cell anemia is a good example of overdominance where the heterozygote has advantages over either of the homozygotes, recessive or dominant.

An example of epistasis is sweet pea flower color.... i hope this doesn't get confusing...

Epistatic interactions arise due to 2 or more proteins participating in a common function. For my example, Allele A encodes a functional version of enzyme A while allele a encodes a nonfunctional version of the enzyme. The same goes for B and b.

Example: Colorless flower --via enzyme A---> Colorless intermediate

Colorless intermediate -----via enzyme B-----> Purple flower

So, you need at least one dominant allele for enzyme A and enzyme B in order to produce purple flowers. If you have 2 homozygous recessive for either enzyme A or enzyme B, that means either enzyme A or B or possibly both are not functional and the purple pigment will not be expressed.

 

[Albuterol]

sickle cell anemia is an example of a missense mutation where 1 aa is replaced with another.

 

[JBarr29]

sickle cell anemia is like the poster child example for heterozygous advantage. I think that is the answer you are looking for.