Where is engrailed expressed in the Drosophila embryo?
engrailed is first expressed in early gastrulating embryos, three to four hours after fertilization. The first stripe is just posterior to the deep groove subdividing the head (cephalic furrow). Subsequently, 13 other stripes appear along the longitudinal axis of the embryo.
What does engrailed gene do?
The engrailed gene is thought to be a ‘selector’ gene that controls the expression of other genes to confer a ‘posterior identity’ on groups of cells that are related to each other by lineage. It has a late role in patterning the wing margin, which includes cells within the anterior compartment.
What is engrailed expression?
engrailed (en) is a segmentation gene expressed in a series of stripes throughout embryonic development. Here, I show that regulatory sequences for striped expression are present within the first intron of en. The 1-kb intron is able to confer striped expression early, but not late, in development.
Is engrailed a transcription factor?
Engrailed (En) is a member of the homeobox gene family, which encodes a homeodomain-containing transcription factor that is essential during early development.
Where is engrailed expressed?
In the ventral ganglion engrailed appears to be expressed by a subset of cells, primarily in the posterior regions of each segment. In wing discs from animals that are homozygous for the en1 mutation, the pattern of expression of the gene is altered, as opposed to being simply reduced uniformly in the posterior cells.
Why is engrailed called a selector gene?
First known for its role in arthropod embryological development, working in consort with the Hox genes, engrailed has been found to be important in other areas of development. It acts as a “selector” gene, conferring a specific identity to defined areas of the body, and co-ordinating the expression of downstream genes.
What does engrailed protein do?
Engrailed acts in each anterior compartment to suppress proteins made in the posterior compartments, such as Wingless, Decapentaplegic, Patched, Deformed and Cubitus interrruptus. EN also has some segment specific effects, such as downregulating Ultrabithorax in parasegment six.
Is engrailed a gap gene?
Segment polarity genes are expressed in the embryo following expression of the gap genes and pair-rule genes. The most commonly cited examples of these genes are engrailed and gooseberry in Drosophila melanogaster.