title: Tissue landscape alters adjacent cell fates during Drosophila egg development.
abstract: Extracellular signalling molecules control many biological processes, but the influence of tissue architecture on the local concentrations of these factors is unclear. Here we examine this issue in the Drosophila egg chamber, where two anterior cells secrete Unpaired (Upd) to activate Signal transducer and activator of transcription (STAT) signalling in the epithelium. High STAT signalling promotes cell motility. Genetic analysis shows that all cells near the Upd source can respond. However, using upright imaging, we show surprising asymmetries in STAT activation patterns, suggesting that some cells experience different Upd levels than predicted by their location. We develop a three-dimensional mathematical model to characterize the spatio-temporal distribution of the activator. Simulations show that irregular tissue domains can produce asymmetric distributions of Upd, consistent with results in vivo. Mutant analysis substantiates this idea. We conclude that cellular landscape can heavily influence the effect of diffusible activators and should be more widely considered.
authors.affiliation: Department of Biological Sciences, University of Maryland, Baltimore County (UMBC), 1000 Hilltop Circle, Baltimore, Maryland 21250, USA.
authors.forename: Lathiena A
authors.initials: LA
authors.lastname: Manning
authors.affiliation: Department of Mathematics and Statistics, UMBC, 1000 Hilltop Circle, Baltimore, Maryland 21250, USA.
authors.forename: Ann Marie
authors.initials: AM
authors.lastname: Weideman
authors.affiliation: Department of Mathematics and Statistics, UMBC, 1000 Hilltop Circle, Baltimore, Maryland 21250, USA.
authors.forename: Bradford E
authors.initials: BE
authors.lastname: Peercy
authors.affiliation: Department of Biological Sciences, University of Maryland, Baltimore County (UMBC), 1000 Hilltop Circle, Baltimore, Maryland 21250, USA.
authors.forename: Michelle
authors.initials: M
authors.lastname: Starz-Gaiano
mesh_terms: D000818:Animals; D022762:CCAAT-Enhancer-Binding Proteins / Q000235:genetics / Q000378:metabolism; D004330:Drosophila / Q000196:embryology / Q000502:physiology*; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D005260:Female; D008297:Male; D008954:Models, Biological; D010063:Ovum / Q000254:growth & development; D051880:Receptors, Notch / Q000378:metabolism; D050791:STAT Transcription Factors / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism*
chemical_list: D022762:CCAAT-Enhancer-Binding Proteins; D029721:Drosophila Proteins; C497759:N protein, Drosophila; D051880:Receptors, Notch; D050791:STAT Transcription Factors; D014157:Transcription Factors; C115570:upd1 protein, Drosophila; C077246:slbo protein, Drosophila