title: Proliferative events and apoptotic remodelling in retinal development of common toad (Bufo bufo).
abstract: Proliferation and apoptosis are fundamental processes in the development of the retina, and a proper balance of the two phenomena is crucial to correct development of the organ. Despite intense investigation in different vertebrates, only a few studies have analyzed the cell death and the cell division quantitatively in the same species during development. Here we studied the time course of apoptosis and proliferation in the retina of common toad, Bufo bufo, and discuss the findings in an evolutionary perspective. We found cells that were dividing first scattered throughout the retina, then, in later stages, proliferation was confined to the ciliary marginal zone. This pattern was confirmed by the expression of the proliferative marker PCNA. Both proliferation and apoptosis occurred in successive waves, and two apoptotic peaks were detected: one at premetamorphosis 1 and the second at prometamorphosis. PARP-1, a known molecular marker of apoptosis, was used to confirm the data obtained by counting pyknotic nuclei. In summary, proliferative and apoptotic waves display an inverse time-relationship through development, with apoptotic peaks coinciding with low proliferation phases. In a comparative perspective, amphibians follow a developmental pattern similar to other vertebrates, although with different timing.
authors.affiliation: Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, Second University of Naples, Caserta, Italy.
authors.forename: Claudia
authors.initials: C
authors.lastname: Pinelli
authors.affiliation: Department of Biology, University of Naples "Federico II", MSA Campus, Naples, Italy.|Institute of Neurophysiology and Cellular Biophysics, University of Göttingen, Göttingen, Germany.
authors.forename: Alfredo
authors.initials: A
authors.lastname: Sansone
authors.affiliation: Department of Biology, University of Naples "Federico II", MSA Campus, Naples, Italy.
authors.forename: Anna
authors.initials: A
authors.lastname: De Maio
authors.affiliation: Department of Biology, University of Naples "Federico II", MSA Campus, Naples, Italy.
authors.forename: Antonietta
authors.initials: A
authors.lastname: Morgillo
authors.affiliation: Department of Biology, University of Naples "Federico II", MSA Campus, Naples, Italy.
authors.forename: Anna
authors.initials: A
authors.lastname: Scandurra
authors.affiliation: Department of Biology, University of Naples "Federico II", MSA Campus, Naples, Italy.
authors.forename: Biagio
authors.initials: B
authors.lastname: D'Aniello
mesh_terms: D000818:Animals; D017209:Apoptosis; D002023:Bufo bufo / Q000254:growth & development*; D049109:Cell Proliferation; D007814:Larva / Q000166:cytology / Q000254:growth & development; D008675:Metamorphosis, Biological; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism; D012160:Retina / Q000166:cytology / Q000254:growth & development*
chemical_list: D018809:Proliferating Cell Nuclear Antigen; D011065:Poly(ADP-ribose) Polymerases