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

Une relation contraire entre deux gènes est l’épistasie, où un gène masque ou modifie l’expression d’un autre. On dit que le gène d’influence est épistatique au gène masqué.
Par exemple, un gène qui code pour la protéine 1 liée à la tyrosinase, ou TYRP1, détermine la couleur du pelage des chiens - noir ou brun.
Un autre gène, Tyr, code pour l’enzyme tyrosinase, qui est responsable de la pigmentation chez les animaux. Une mutation dans ce gène peut entraîner l’absence de pigment, ce qui donne un chien albinos qui n’a aucune coloration.
L’ordre dans lequel ces deux gènes sont exprimés peut être déterminé par un test d’épistasie.
Si une mutation dans le gène Tyr produit un chien albinos qui a toujours le gène TYRP1 de type sauvage, on peut conclure que le gène Tyr masque l’effet du gène TYRP1. Cela signifierait que Tyr est épistatique à TYRP1.

<ol>
	<li>Michels, C.A. (2002). Analyse de l’épistasie. Dans Techniques génétiques pour la recherche biologique, C.A. Michels (éd.). https://doi.org/10.1002/0470846623.ch6</li>
	<li>Bernstein, Harris, Henry C. Byerly, Frederic A. Hopf et Richard E. Michod. « Dommages génétiques, mutation et évolution du sexe. » Science 229, n° 4719 (1985) : 1277-1281.</li>
</ol>

analyse de l'épistasie

Epistasis Analysis

Bien que Mendel ait choisi sept caractères non apparentés dans les pois pour étudier la ségrégation génétique, la plupart des caractères impliquent des interactions entre plusieurs gènes qui créent un spectre de phénotypes. Lorsque l'interaction de divers gènes ou allèles à différents endroits influence un phénotype, on parle d'épistasie. L'épistasie implique souvent qu'un gène masque ou interfère avec l'expression d'un autre (épistasie antagoniste). L'épistasie se produit souvent lorsque différents gènes font partie de la même voie biochimique. L'expression d'un gène peut dépendre du produit d'un gène dans la même voie biochimique.

Analyse épistatique

L'étude des interactions épistatiques permet aux chercheurs de déterminer la relation fonctionnelle entre les gènes, l'ordre des gènes dans une voie et l'impact quantitatif des différents allèles sur les phénotypes. Considérons une réaction biochimique catalysée par plusieurs protéines codées par différents gènes. Les gènes impliqués dans ces réactions biochimiques peuvent masquer ou inhiber d'autres gènes impliqués dans la même voie biochimique, un phénomène appelé épistasie. On dit que ces gènes font partie d'un groupe d'épistasie. En analysant la relation épistatique entre différents gènes, les scientifiques peuvent construire une carte de l'ordre de fonction qui montre la séquence des événements et des gènes impliqués dans une voie. Ce processus est appelé analyse épistatique. Les allèles sélectionnés pour l'analyse épistatique doivent avoir des phénotypes distincts.

Ainsi, depuis l'introduction du concept d'épistasie, il est devenu de plus en plus évident que la plupart des systèmes biologiques impliquent de nombreux éléments génétiques qui interagissent les uns avec les autres de manière multiple et complexe.

Analyse de l'épistasie

Bien que Mendel ait choisi sept caractères non apparentés chez les pois pour étudier la ségrégation génétique, la plupart des traits impliquent de multiples interactions génétiques qui créent un spectre de ...

Education

Enseignement

JoVE Core

Molecular Biology

Biologie moléculaire

Unit 2

Unité 2

Analyzing Gene Expression and Function

Analyse de l'expression et de la fonction géniques

KEY TERMS AND CONCEPTS

TERMES ET CONCEPTS CLÉS

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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epistasis analysis

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 Biologie Moléculaire illustre les processus moléculaires au sein de la cellule grâce à des leçons vidéos claires et concises. Les applications de ces concepts sont ensuite démontrées grâce à des expériences concrètes en laboratoire.

Gene Interaction Maps in Epistasis

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