Planar polarization of the denticle field in the Drosophila embryo: roles for Myosin II (zipper) and fringe.
Epithelial planar cell polarity (PCP) allows epithelial cells to coordinate their development to that of the tissue in which they reside. The mechanisms that impart PCP as well as effectors that execute the polarizing instructions are being sought in many tissues. We report that the epidermal epithelium of Drosophila embryos exhibits PCP. Cells of the prospective denticle field, but not the adjacent smooth field, align precisely. This requires Myosin II (zipper) function, and we find that Myosin II is enriched in a bipolar manner, across the parasegment, on both smooth and denticle field cells during denticle field alignment. This implies that actomyosin contractility, in combination with denticle-field-specific effectors, helps execute the cell rearrangements involved. In addition to this parasegment-wide polarity, prospective denticle field cells express an asymmetry, uniquely recognizing one cell edge over others as these cells uniquely position their actin-based protrusions (ABPs; which comprise each denticle) at their posterior edge. Cells of the prospective smooth field appear to be lacking proper effectors to elicit this unipolar response. Lastly, we identify fringe function as a necessary effector for high fidelity placement of ABPs and show that Myosin II (zipper) activity is necessary for ABP placement and shaping as well.
Walters
James W
JW
Department of Cell and Developmental Biology, University of Pennsylvania Medical Center, Philadelphia 19104-6058, USA.
Dilks
Stacie A
SA
DiNardo
Stephen
S
D000199:Actins / Q000378:metabolism; D000483:Alleles; D000818:Animals; D019521:Body Patterning; D019070:Cell Lineage; D004330:Drosophila / Q000196:embryology*; D029721:Drosophila Proteins / Q000737:chemistry*; D004331:Drosophila melanogaster; D004625:Embryo, Nonmammalian / Q000378:metabolism; D004817:Epidermis / Q000196:embryology; D005260:Female; D018507:Gene Expression Regulation, Developmental; D047908:Intracellular Signaling Peptides and Proteins / Q000037:antagonists & inhibitors; D008297:Male; D024462:Myosin Type II / Q000737:chemistry*; D017351:N-Acetylglucosaminyltransferases / Q000737:chemistry*; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors; D054460:rho-Associated Kinases
D000199:Actins; D029721:Drosophila Proteins; D047908:Intracellular Signaling Peptides and Proteins; D017351:N-Acetylglucosaminyltransferases; C090576:fng protein, Drosophila; D017346:Protein Serine-Threonine Kinases; D054460:rho-Associated Kinases; D024462:Myosin Type II