The Rap1 small GTPase affects cell fate or survival and morphogenetic patterning during Drosophila melanogaster eye development

The Drosophila melanogaster eye has been instrumental for determining both how cells communicate with one another to determine cell fate, as well as cell morphogenesis and patterning. Here, we describe the effects of the small GTPase Rap1 on the development of multiple cell types in the D. melanogaster eye. Although Rap1 has previously been linked to RTK-Ras-MAPK signaling in eye development, we demonstrate that manipulation of Rap1 activity is modified by increase or decrease of Delta/Notch signaling during several events of cell fate specification in eye development. In addition, we demonstrate that manipulating Rap1 function either in primary pigment cells or in interommatidial cells affects cone cell contact switching, primary pigment cell enwrapment of the ommatidial cluster, and sorting of secondary and tertiary pigment cells. These data suggest that Rap1 has roles in both ommatidial cell recruitment/survival and in ommatidial morphogenesis in the pupal stage. They lay groundwork for future experiments on the role of Rap1 in these events.

Automated summary

In this study, the effects of Rap1, a small GTPase, on the development of different cell types in the Drosophila melanogaster eye were investigated. It was found that the activity of Rap1 is regulated by the Delta/Notch signaling pathway and plays a role in determining cell fate during eye development. Manipulation of Rap1 function also affected cone cell contact switching, primary pigment cell enwrapment, and sorting of secondary and tertiary pigment cells. These findings suggest that Rap1 is involved in both cell recruitment/survival and morphogenesis during pupal eye development, providing a basis for further research on its role in these events.