Hox Genes Quizlet
homeotic genes in a fruit fly.
Antennapedia and Ultrabithorax
What happens when homeotic genes are overactivated or inactivated by mutation?
Body structures may develop in the wrong place—sometimes dramatically so!
What is a gap gene?
Gap genes are activated through interactions between the protein products of the maternal effects genes, and they also regulate each other. They're responsible for defining large, multi-segment regions of the fly, the ones that are missing when the gene is mutated.
Where can Hox genes be found?
Hox genes are found in many animals, including fruit flies, mice, and humans. Mutations in human Hox genes can cause genetic disorders.
How are Hox genes turned on?
Hox genes are turned on by a cascade of regulatory genes; the proteins encoded by early genes regulate the expression of later genes.
what do animal homeotic genes encode transcription factor proteins contain?
Most animal homeotic genes encode transcription factor proteins that contain a region called the homeodomain and are called Hox genes.
What is a Hox Cluster.
The Hox cluster is a great example of how developmental genes can be both preserved and modified through evolution, particularly when they are copied by a duplication. Hox genes also show just how powerful a developmental gene can be, especially when it is a transcription factor that turns many target genes on or off to activate a particular genetic "program."
Pair-rule genes
When a pair-rule gene is missing due to mutation, there is a loss of structures in the segment regions where the gene is normally expressed.
Homeotic genes
master regulator genes that direct the development of particular body segments or structures.