Analysis of pattern formation in the epidermis of the adult abdomen of Drosophila by in vivo 4D-microscopy
Zusammenfassung der Projektergebnisse
The analysis of the behaviour of the histoblasts in wild-type pupae showed that the histoblasts migrate in two phases in which cells do not change neighbours extensively, and the mitoses do not show any preferential orientation. However, after mitosis the sisters become preferentially aligned with the direction of movement. Thus, the development of the abdomen differs from the development of the wing imaginal disc and the embryonic germband in Drosophila, where oriented mitoses and local cell rearrangements appear to direct morphogenesis. During their movement, cells of the anterior and posterior compartments differ in their behaviour. A preliminary analysis of the establishment of polarity in the abdominal epidermis suggests that the two systems important to establish PCP might not be significantly employed during normal development. However, wild-type cells around clones mutant for the ds-system appear to divide towards the clone, suggesting that at least one system that builds PCP could provide an instructive signal for cell division orientation during the spreading of the histoblasts. Furthermore, first results suggest that cell sorting in a rigid epithelial sheet is subtle, only leading to moderate changes in neighbourhood relations. It was rather unexpected that the cell divisions of the histoblasts appear to be undirected – one might have expected that they would be oriented in a particular direction as the histoblasts display a strong polarised behaviour when they migrate towards the midline. However, the preliminary results of the clonal analysis suggest that cell division orientation could be influenced by PCP during the spreading of the histoblasts. Furthermore, I found that, in most of the performed experiments, some clonal cells die. This suggests that in most cases, clonal cells are less fit than their wild-type neighbours. The frequent occurrence of cell death might be rather surprising – this highlights the value of live observations of development, since fixed preparations might not have allowed me to detect single dying cells.
Projektbezogene Publikationen (Auswahl)
- (2007). Myosin II regulates complex cellular arrangement and epithelial architecture in Drosophila. Dev Cell 13, 717-729
Escudero LM, Bischoff M and Freeman M
