100% satisfaction guarantee Immediately available after payment Both online and in PDF No strings attached
logo-home
Summary Interactions between genes £2.99
Add to cart

Summary

Summary Interactions between genes

 5 views  0 purchase

Detailed notes on Interactions between genes

Preview 1 out of 2  pages

  • February 21, 2022
  • 2
  • 2018/2019
  • Summary
All documents for this subject (30)
avatar-seller
7joshlyons7
BLGY1232 Interactions between genes

Epistatic interactions
 Most common
 Epistasis – an interaction between 2 different genes so that an allele of one of them
(epistatic gene) interferes with or inhibits the phenotypic expression of the other
(hypostatic gene)
 Recessive epistasis – the action of one gene is required for the expression of another
 coat colour in mice 9:4:3  Aa cc and AA cc mice have the same phenotype as aa
cc mice, Epistasis of cc over A-, white hairs produced irrespective of the genotype at
locus A  C is epistatic to A Not a single gene trait (not 3:1), probably 2 genes
(9+6+1=16), probably epistasis (9+6+1 = 9+4+3)  1/16 probably double recessive
 Duplicate recessive epistasis – the phenotype requires both genes for its expression
probably 2 genes (9+7=16), probably 2 epistatic interacting genes (9+4+3=9+7) 
you cannot get a wildtype phenotypes when grossing 2 parents with mutants in the
same gene (GENETIC COMPLEMENTATION)
 Complementation testing is routinely carried out to determine how many genes
control a phenotype;
1. Collect a population of independently isolated mutants showing the same
mutant trait
2. Cross them, in pairwise combinations
3. Count how many crosses produce mutant offspring (mutations in the same
gene) and how many crosses produce wildtype offspring (mutants in different
genes)
4. If the progeny of such a cross show restoration of the wild-type phenotype
the mutations carried by the parents are in different genes – the mutants are
said to complement each other
5. If the progeny still exhibit the mutant phenotype the mutations are in the
same gene – individuals that don’t complement one another form a
complementation group – the number of complementation groups defines
the number of different genes that control the trait in question

Lethal alleles
 Recessive lethal – absence of a gene product leads to death in homozygotes
 Dominant lethal – both homozygotes and heterozygotes carrying the allele will die
 Sex linked lethal – homozygotes of the homogametic sex will die and heterozygotes
will survive, however individuals of the heterogametic sex will die if they inherit the
lethal allele
 Usually loss-of-function mutations are recessive

Segregation patterns
 Co-dominance and Intermediate dominance F2 generation has 1:2:1
 Two alleles are said to display intermediate dominance (also sometimes called
incomplete dominance) when the heterozgote offspring of two true-breeding
parents shows a phenotype that is not identical to either of the parents, but is “in-
between”  blending inheritance

The benefits of buying summaries with Stuvia:

Guaranteed quality through customer reviews

Guaranteed quality through customer reviews

Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.

Quick and easy check-out

Quick and easy check-out

You can quickly pay through credit card for the summaries. There is no membership needed.

Focus on what matters

Focus on what matters

Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!

Frequently asked questions

What do I get when I buy this document?

You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.

Satisfaction guarantee: how does it work?

Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.

Who am I buying these notes from?

Stuvia is a marketplace, so you are not buying this document from us, but from seller 7joshlyons7. Stuvia facilitates payment to the seller.

Will I be stuck with a subscription?

No, you only buy these notes for £2.99. You're not tied to anything after your purchase.

Can Stuvia be trusted?

4.6 stars on Google & Trustpilot (+1000 reviews)

52355 documents were sold in the last 30 days

Founded in 2010, the go-to place to buy revision notes and other study material for 14 years now

Start selling
£2.99
  • (0)
Add to cart
Added