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Name: Aliya
Status: Student
Grade:  9-12
Location: N/A
Country: United States
Date: October 2005

What are homeotic genes and homeotic mutants?

Homeotic genes are genes involved in developmental patterns and sequences. For example, homeotic genes are involved in determining where, when, and how body segments develop in flies. Alterations in these genes cause changes in patterns of body parts, sometimes causing dramatic effects such as legs growing in place of antennae or an extra set of wings or, in the case of plants, flowers with abnormal numbers of parts. An individual carrying an altered (mutant) version of a homeotic gene is known as a homeotic mutant.

C. Perkins

In your house you have a fuse box (or circuit breaker box). You can turn off one or two breakers at once, or at the top of the box is a switch that controls the whole house. In the embryo, there are certain genes that have control over a whole group of other genes and the time at which they are expressed. These are called homeobox or homeotic genes. All animals have them and for the most part they are similar. They are the genes that lay out the basic plan of the body. If they are mutated, they can change either the way the body is laid out, or inactivate the genes that control a whole part of the body. For example, snakes are reptiles by definition, but have no limbs. Research shows that certain of the homeobox genes that control the genes that control limb development are mutated. For more information about this, view the video at this link:


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