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Polyamines and ripening of photoreceptor outer segments in chicken embryos
Author(s) -
Taibi G.,
Schiavo M.R.,
Nicotra C.
Publication year - 1995
Publication title -
international journal of developmental neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.761
H-Index - 88
eISSN - 1873-474X
pISSN - 0736-5748
DOI - 10.1016/0736-5748(95)00056-9
Subject(s) - putrescine , polyamine oxidase , spermidine , spermine , biochemistry , biology , polyamine , ornithine decarboxylase , microbiology and biotechnology , embryo , retina , enzyme , neuroscience
Polyamines and their related monoacetyl derivatives were studied in rod outer segment (ROS) and cone outer segment (COS) of photoreceptor cells from chick embryo retina during eye development (7th–18th days). Putrescine was found to be necessary, in the second phase of retinogenesis, to sustain both ROS and COS differentiation and, after acetylation, γ‐aminobutyric acid synthesis. On the other hand, spermidine and even more spermine intervene in the third phase of development when photoreceptors mature. Moreover, the presence of N 1 ‐acetylspermidine already at the 7th day indicates that in the outer segment of photoreceptor cells too, as in the whole retina, putrescine synthesis comes about by two pathways. One pathway involves ornithine decarboxylase; the other, spermidine/spermine N 1 ‐acetyltransferase and FAD‐dependent polyamine oxidase activities that convert spermidine to putrescine via N 1 ‐acetylspermidine. These different biosynthetic pathways are probably also decisive in permitting γ‐aminobutyric acid synthesis, which is very important in the ripening process of neural retina.