Cells come in different shapes. They can be round, columnar, spindle shaped, they come with or without protrusions, and they can change their shape rapidly during development. Interactions between cells allow them to build highly organized tissue structures. What are the molecules that control cell shape and movements? To find and analyze the factors that are involved in morphogenesis my laboratory uses a genetic approach. We study the development of the ovary of Drosophia melanogaster that consists of a regular array of tubes in which the eggs mature, and gene mutations, which disturb the formation of the egg tubes cause sterility. With the help of such mutations we isolate and characterize genes that regulate morphogenetic processes in ovarian development on the molecular, cellular and genetic level. Our current work focuses on the function of several morphogenetic regulators, such as adhesion molecules of the cadherin family and the transcription factors bric