Question

Describe the initial signals that define axis polarity in Drosophila.

Answer 1

Drosophila melanogaster belongs to the family Drosophilidae and order Diptera. It is also called as fruit fly and has been widely used as the model organism for various researches in different fields like genetics, pathogenesis, evolutionary history, and physiology. In recent years circadian rhythm has also been discovered in the fruitfly.

Essential processes like gene transcription and expression along with protein interactions that lead to the early development of the Drosophila has been widely studied. Various signals define the anterior-posterior and dorso-ventral axis in the fruitfly. “Maternal effect genes” are the signals that are responsible for the initiation of “anterior-posterior polarity”. The anterior portion of the anterior-posterior axis in the fly is formed by the genes activated by the “Bicoid” and “Hunchback” proteins. Caudal proteins activate the genes that are responsible for the development of posterior portion in the fly.

Dorso-ventral polarity is initiated by the signals called “Dorsal proteins” that enter into the nucleus and position the nucleus at the dorsal anterior side. Dorsal proteins also define the fates of the ventral cells and also help in repressing the genes that are specific for dorsal side development.