Question

Explain how segments are established in the Drosophila embryo

please be detailed and use exact names for components involved

Answer 1

All arthropods, are segmented. The body of Drosophila is built from 14 segments:
3 segments make up the with its antennae and mouth parts.
3 segments make up the . Each thoracic segment has a pair of legs (insects are the six-legged creatures).and the middle thoracic segment carries a single pair of wings.
The hind segment a pair of halteres.8 .

signals guide segment formation----->

The process begins with the gradients of messenger RNA (mRNA) that the mother deposited in her egg before it was fertilized.

Shortly after fertilization, these are translated into their proteins with

●a gradient of bicoid diminishing from anterior to posterior and
●a gradient of nanos diminishing from posterior to anterior.
●Bicoid protein is a transcription factor. It binds to the promoter of a gene called hunchback, turning it ON.
● Nanos protein binds to hunchback mRNAs, inhibiting their translation.
These effects combine to produce a high level of hunchback protein at the anterior of the embryo; with a sharp cut-off toward the posterior.The hunchback protein is also a transcription factor (as we shall see).

These concentration gradients regulate the turning on and off of other genes in sharply-defined regions of the embryo.These establish the various segments of the body