Name: gene interaction maps in epistasis
Uploaded: 2023-04-30T10:14:33.000Z
Duration: 1 min 9 s
Channel: JoVE

A contrary relationship between two genes is epistasis, where one gene masks or alters the expression of another. The influencing gene is said to be epistatic to the gene being masked.
For example, a gene that codes for tyrosinase-related protein 1, or TYRP1, determines the coat color of dogs &#8212;&#160; black or brown.
Another gene, Tyr, codes for the enzyme tyrosinase, which is responsible for pigmentation in animals. A mutation in this gene can cause the absence of pigment, resulting in an albino dog which lacks any coloration.
The order in which these two genes are expressed can be determined by an epistasis test.
If a mutation in the Tyr gene produces an albino dog that still has the wild-type TYRP1 gene, it can be concluded that the Tyr gene masks the effect of the TYRP1 gene. This would mean that Tyr is epistatic to TYRP1.

epistasis analysis

Epistasis Analysis

Although Mendel chose seven unrelated traits in peas to study gene segregation, most traits involve multiple gene interactions that create a spectrum of phenotypes. When the interaction of various genes or alleles at different locations influences a phenotype, this is called epistasis. Epistasis often involves one gene masking or interfering with the expression of another (antagonistic epistasis). Epistasis often occurs when different genes are part of the same biochemical pathway. The expression of a gene might depend on a gene product in the same biochemical pathway.
Epistatic analysis
The study of epistatic interactions allows researchers to determine the functional relationship between genes, the ordering of genes in a pathway, and how different alleles quantitatively impact phenotypes. Consider a biochemical reaction catalyzed by multiple proteins coded by different genes. The genes involved in such biochemical reactions can mask or inhibit other genes involved in the same biochemical pathway, a phenomenon called epistasis. Such genes are said to be in one epistasis group. By analyzing the epistatic relationship between different genes, scientists can construct an order-of-function map that shows the sequence of events and genes involved in a pathway. This process is called epistatic analysis. The alleles selected for the epistatic analysis must have distinct phenotypes.
As such, since the concept of epistasis was introduced, it has become increasingly clear that most biological systems involve many genetic elements that interact with one another in multiple and complex ways.

Although Mendel chose seven unrelated traits in peas to study gene segregation, most traits involve multiple gene interactions that create a spectrum of ...

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JoVE Core

Molecular Biology

Unit 2

Analyzing Gene Expression and Function

KEY TERMS AND CONCEPTS

gene interaction maps in epistasis

Gene interaction maps in epistasis show how different genes work together to shape a phenotype. In epistasis, the interaction of genes or alleles at different locations affects the final trait. This often happens when one gene masks or interferes with the expression of another gene.

Epistasis is common when genes are part of the same biochemical pathway. In that case, the expression of one gene can depend on a gene product made earlier in the pathway. Genes that mask or inhibit other genes in the same pathway are considered part of one epistasis group.

Epistatic analysis uses these interactions to reveal how genes are related. Scientists can use it to identify the functional relationship between genes, determine the order of genes in a pathway, and see how different alleles affect phenotypes in a quantitative way. When multiple proteins encoded by different genes take part in a biochemical reaction, epistatic analysis can help build an order-of-function map that shows the sequence of events and the genes involved.

To compare genes in this way, the alleles chosen for analysis must have distinct phenotypes. Since epistasis was first described, it has become clear that many biological systems include genetic elements that interact in complex ways. These interactions help explain why many traits do not follow simple single-gene patterns.

Gene Interaction Maps in Epistasis

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Gene interaction maps in epistasis show how different genes work together to shape a phenotype. In epistasis, the interaction of genes or alleles at different locations affects the final trait. This often happens when one gene masks or interferes with the expression of another gene. Epistasis is common when genes are part of the same biochemical pathway. In that case, the expression of one gene can depend on a gene product made earlier in the pathway. Genes that mask or inhibit other genes in...

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key terms and concepts

Explore how epistasis reveals gene interactions, pathway order, and phenotype changes through epistatic analysis in high school biology.

Gene Interaction Maps in Epistasis | JoVE K12

molecular biology

JoVE Core Molecular Biology showcases the molecular processes of the cell through clear and concise animated video lessons. Additionally, in scientist-in-action videos, these concepts' application is demonstrated through real experiments in modern laboratories.

Gene Interaction Maps in Epistasis

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