Role of spastin in apical domain control along the rhabdomere elongation in Drosophila photoreceptor.
BACKGROUND
Mutations in spastin are the most common cause of hereditary spastin paraplegia, a neurodegenerative disease. In this study, the role of spastin was examined in Drosophila photoreceptor development.


RESULTS
The spastin mutation in developing pupal eyes causes a mild mislocalization of the apical membrane domain at the distal section, but the apical domain was dramatically reduced at the proximal section of the developing pupal eye. Since the rhabdomeres in developing pupal eyes grow from distal to proximal, this phenotype strongly suggests that spastin is required for apical domain maintenance during rhabdomere elongation. This role of spastin in apical domain modulation was further supported by spastin's gain-of-function phenotype. Spastin overexpression in photoreceptors caused the expansion of the apical membrane domain from apical to basolateral in the developing photoreceptor. Although the localizations of the apical domain and adherens junctions (AJs) were severely expanded, there were no defects in cell polarity.


CONCLUSIONS
These results strongly suggest that spastin is essential for apical domain biogenesis during rhabdomere elongation in Drosophila photoreceptor morphogenesis.
Chen
Geng
G
Department of Biology, Baylor University, Waco, Texas, United States of America.
League
Garrett P
GP
Nam
Sang-Chul
SC
D000251:Adenosine Triphosphatases / Q000235:genetics* / Q000502:physiology*; D000818:Animals; D029721:Drosophila Proteins / Q000235:genetics* / Q000378:metabolism / Q000502:physiology*; D004331:Drosophila melanogaster / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental; D049452:Green Fluorescent Proteins / Q000378:metabolism; D008954:Models, Biological; D008957:Models, Genetic; D009154:Mutation; D055355:Opsins / Q000378:metabolism; D010641:Phenotype; D010786:Photoreceptor Cells / Q000378:metabolism*; D017956:Photoreceptor Cells, Invertebrate / Q000378:metabolism; D017434:Protein Structure, Tertiary; D011679:Pupa / Q000378:metabolism
D029721:Drosophila Proteins; D055355:Opsins; D049452:Green Fluorescent Proteins; D000251:Adenosine Triphosphatases; C501874:spas protein, Drosophila