Name: using crosses to group mutations
Uploaded: 2021-04-07T12:12:00.000Z
Duration: 49 s
Channel: JoVE

Parfois, différentes mutations peuvent produire le même phénotype, comme la perte de coloration des plumes d’oiseaux. Que ces mutations se trouvent dans le même gène ou dans deux gènes différents, peut être déterminé à l’aide d’un test de complémentation.
Considérez l’élevage entre deux poulets mutants. Si le même gène est muté chez les deux parents, la progéniture héritera de la mutation et apparaîtra blanche.
D’autre part, si la progéniture apparaît brune comme l’oiseau de type sauvage, cela indiquerait que les parents avaient des mutations dans deux gènes différents.
Bien que chaque gène parental ait une mutation, ils ont travaillé ensemble pour produire un phénotype de type sauvage. Ce phénomène s’appelle la complémentation.

<ol>
	<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>

tests de complémentation

Complementation Tests

Un test de complémentation est un simple croisement permettant d'identifier si les deux mutations sont localisées sur le même gène ou sur des gènes différents. Elle a été réalisée pour la première fois par Edward Lewis dans les années 1940 alors qu'il travaillait sur les mouches des fruits. Il a développé le test pour identifier l'emplacement et la disposition des différentes mutations sur les chromosomes.

Les organismes hétérozygotes pour différentes mutations sont croisés par paires dans toutes les combinaisons. Si elles sont présentes sur des gènes différents, les mutations peuvent se compléter en fournissant l'élément génétique manquant produisant un phénotype de type sauvage. Cependant, si les deux mutations appartiennent au même gène, elles ne peuvent pas se compléter et ne présentent pas le phénotype sauvage. Les mutations qui ne parviennent pas à se compléter sont dites appartenant au même groupe de complémentation. Les mutations qui se complètent appartiennent à différents groupes de complémentation.

Tests de complémentation

Un test de complémentation est un simple croisement permettant d’identifier si les deux mutations sont situées sur le même gène ou sur des gènes différents. Il a été créé par ...

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

using crosses to group mutations

A complementation test uses a simple cross to find out whether two mutations are in the same gene or in different genes. It helps show how mutations are arranged on chromosomes. Edward Lewis first performed this test in the 1940s while studying fruit flies.

To do the test, organisms heterozygous for different mutations are crossed pairwise in all combinations. If the mutations are in different genes, they can complement each other. In that case, each mutation provides the missing genetic element, and the offspring shows a wild-type phenotype.

If both mutations are in the same gene, they cannot complement each other. The offspring does not show the wild-type phenotype. Mutations that fail to complement each other are placed in the same complementation group, while mutations that do complement each other belong to different complementation groups.

Using Crosses to Group Mutations

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complementation tests

A complementation test uses a simple cross to find out whether two mutations are in the same gene or in different genes. It helps show how mutations are arranged on chromosomes. Edward Lewis first performed this test in the 1940s while studying fruit flies. To do the test, organisms heterozygous for different mutations are crossed pairwise in all combinations. If the mutations are in different genes, they can complement each other. In that case, each mutation provides the missing genetic...

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key terms and concepts

See how complementation tests use pairwise crosses to tell whether mutations are in the same gene or different genes, and how complementation groups are formed.

Using Crosses to Group Mutations | 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.

Using Crosses to Group Mutations

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