Segments expressing the An Hox gene are associated with the formation of antennae. True False
The correct answer and explanation is:
Correct Answer: True
The Antennapedia (Antp) gene, which is part of the Hox gene family in Drosophila melanogaster (fruit fly), is indeed associated with the formation and identity of body segments, including those related to antennae and legs. Hox genes are crucial for determining the identity of different body segments during embryonic development in animals.
The An Hox gene, often referring to the Antennapedia complex or Antp gene specifically, controls whether a segment will develop an antenna or a leg. In the normal genetic configuration, antennae develop in the head region of fruit flies. However, when the Antp gene is misexpressed or mutated, the cells in the head that are supposed to form antennae instead form legs. This phenomenon results in a well-known mutation called Antennapedia, where legs grow in place of antennae.
This observation shows that the Hox gene segment is not just present in the antenna region but also actively regulates the positional identity of that segment. The precise regulation of Hox genes ensures that appendages develop in the correct body regions. The misexpression of these genes provides strong evidence for their role in determining segmental identity, especially in model organisms like Drosophila.
Though the Hox genes themselves do not directly “build” the antennae, they provide critical instructions to other genes that lead to the proper development of these structures. In essence, they act like master control switches that activate specific developmental pathways depending on their expression in certain segments.
Therefore, it is correct to say that segments expressing the An Hox gene are associated with the formation of antennae, particularly in terms of segment identity and developmental patterning.