Desplan

Desplan is a gene found in Drosophila melanogaster (the fruit fly) that plays a crucial role in eye development, specifically in the specification of photoreceptor cell fates. It encodes a zinc-finger transcription factor, meaning it regulates the expression of other genes by binding to specific DNA sequences.

Desplan is expressed in a subset of cells within the developing eye disc and is essential for the differentiation of R8 photoreceptor cells, which are the first photoreceptors to differentiate and act as founder cells for the recruitment of other photoreceptors. Without functional Desplan, these R8 cells fail to develop properly, leading to defects in eye formation and visual function.

The Desplan protein interacts with other transcription factors and signaling pathways to control the expression of genes required for R8 cell identity and differentiation. It acts in a complex regulatory network that ensures the correct number and arrangement of photoreceptor cells in the eye.

Mutations in the desplan gene can result in a variety of eye phenotypes, ranging from mild disruptions in ommatidia organization to complete absence of photoreceptor cells. Studies of Desplan and its role in eye development have provided valuable insights into the genetic and molecular mechanisms that control cell fate specification and tissue morphogenesis. Its function is highly conserved in related insect species. The name "Desplan" is derived from "determination-of-spontaneous-planar-polarity".