title: Cofilin/ADF is required for retinal elongation and morphogenesis of the Drosophila rhabdomere.
abstract: Drosophila photoreceptors undergo marked changes in their morphology during pupal development. These changes include a five-fold elongation of the retinal cell body and the morphogenesis of the rhabdomere, the light sensing structure of the cell. Here we show that twinstar (tsr), which encodes Drosophila cofilin/ADF (actin-depolymerizing factor), is required for both of these processes. In tsr mutants, the retina is shorter than normal, the result of a lack of retinal elongation. In addition, in a strong tsr mutant, the rhabdomere structure is disorganized and the microvilli are short and occasionally unraveled. In an intermediate tsr mutant, the rhabdomeres are not disorganized but have a wider than normal structure. The adherens junctions connecting photoreceptor cells to each other are also found to be wider than normal. We propose, and provide data supporting, that these wide rhabdomeres and adherens junctions are secondary events caused by the inhibition of retinal elongation. These results provide insight into the functions of the actin cytoskeleton during morphogenesis of the Drosophila eye.
authors.affiliation: Department of Molecular Cell and Developmental Biology, and Molecular Biology Institute, University of California at Los Angeles, Los Angeles, CA 90095, USA.
authors.forename: Hung
authors.initials: H
authors.lastname: Pham
authors.forename: Hui
authors.initials: H
authors.lastname: Yu
authors.forename: Frank A
authors.initials: FA
authors.lastname: Laski
mesh_terms: D051339:Actin Depolymerizing Factors / Q000235:genetics / Q000378:metabolism*; D022005:Adherens Junctions / Q000378:metabolism; D000818:Animals; D003599:Cytoskeleton / Q000378:metabolism; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000033:anatomy & histology / Q000196:embryology; D005260:Female; D008297:Male; D008840:Microfilament Proteins / Q000235:genetics / Q000378:metabolism*; D009024:Morphogenesis; D009154:Mutation; D010641:Phenotype; D017956:Photoreceptor Cells, Invertebrate / Q000033:anatomy & histology / Q000196:embryology / Q000378:metabolism; D012160:Retina / Q000166:cytology / Q000196:embryology
chemical_list: D051339:Actin Depolymerizing Factors; D029721:Drosophila Proteins; D008840:Microfilament Proteins; C097180:tsr protein, Drosophila