Live imaging of delamination in Drosophila shows that epithelial cell motility and invasiveness are independently regulated

Abstract

AbstractDelamination requires cells to undergo changes in cell-cell adhesion and in cell polarity, motility, and protrusions. This complex process must be precisely regulated during development as well as in pathogenic conditions. To determine the requirements for epithelial delamination, we analyzed the delamination of Drosophila ovary border cells, in which cells delaminate from the epithelial layer and begin to migrate collectively as is also seen in cancer metastasis. We used live imaging to examine cellular dynamics in delamination-defective mutants during the period in which delamination occurs in the wild-type ovary. We found that border cells in slow border cells (slbo), a delaminationdefective mutant, lacked the properties of invasive cellular extensions but acquired motility while JAK/STAT-inhibited border cells lost both cellular properties, suggesting that the invasiveness and motility required for delamination are regulated independently. Our reconstruction experiments showed that motility is not a prerequisite for acquiring invasiveness.