Cell death may regulate visual functionality in the retina of adults of the dipteran Ceratitis capitata.
The white eye mutation in the medfly Ceratitis capitata, like the homologous mutation in Drosophila melanogaster, was shown to impair visual function. Light and electron microscopy, combined with the DNA-end labelling histochemistry (terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling (TUNEL) technique), were used to investigate whether programmed cell death may contribute to the morpho-functional differences between the retina of adults from the white eye and wild type strains. Several photoreceptor nuclei in mature white eye flies appeared smaller and showed intensely Toluidine Blue-stained chromatin masses. At the ultrastructural level, they showed different stages of degeneration, resembling apoptotic figures. Positive TUNEL labelling in the white eye retina indicates that apoptosis may be a candidate mechanism for retinal cell degeneration in adult flies, where visual functionality is altered, to achieve the proper cell number. Apoptosis also appears to occur in the wild type retina in early adult life during normal tissue development.
Conforti
Elena
E
Dipartimento di Biologia Animale, Centro di Studio per l'Istochimica del C.N.R., Università degli Studi di Pavia, Piazza Botta 10, 27100 Pavia, Italy.
Barni
Sergio
S
Pisu
Maria Bonaria
MB
Vaccarone
Rita
R
Malacrida
Anna Rodolfa
AR
Bernocchi
Graziella
G
D000375:Aging / Q000235:genetics*; D000818:Animals; D017209:Apoptosis / Q000235:genetics*; D019521:Body Patterning / Q000235:genetics; D002455:Cell Division / Q000235:genetics; D004175:Diptera / Q000235:genetics / Q000254:growth & development* / Q000648:ultrastructure; D018507:Gene Expression Regulation, Developmental / Q000502:physiology; D020287:In Situ Nick-End Labeling; D008854:Microscopy, Electron; D009154:Mutation / Q000502:physiology*; D017956:Photoreceptor Cells, Invertebrate / Q000254:growth & development* / Q000378:metabolism / Q000648:ultrastructure; D014785:Vision, Ocular / Q000235:genetics*