Ea. Rivas et al., ONTOGENIC DEVELOPMENT OF MEMBRANE-LIPIDS IN THE CHICK OPTIC LOBE, International journal of developmental neuroscience, 14(2), 1996, pp. 93-104
The developmental profiles of the lipid composition and their de novo
synthesis and remodelling in the optic lobe of the chicken were studie
d. The P-32 incorporation to phospholipids showed an active de novo sy
nthesis mainly of phosphatidylinositol and of a particular fraction of
phosphatidylcholine during the early stages of the embryo development
, concomitantly with the beginning of synaptogenesis. This de novo syn
thesis of phospholipids strongly increased at hatching. On the other h
and, phosphatidylnositol presented an active lipid exchange (acylation
-deacylation) in the early stages of embryogenesis, indicating a stron
g incorporation of C-14-arachidonic acid during this period, followed
by a fast drop in specific activity. Two different fractions of phosph
atidylcholine were isolated by high-performance thin-layer chromatogra
phy with a different profile of fatty acid composition, disclosing the
ir different physicochemical behavior, metabolic activities and evolut
ion during embryogenesis. P-32 incorporation into phosphatidylethanola
mine remained very low during the earliest stages of embryogenesis, sh
owing an increase when the process of synaptogenesis began, until hatc
hing, when radioactivity reached a plateau. C-14- arachidonic acid inc
orporation into phosphatidylethanolamine was minimal. Furthermore, the
phosphatidylethanolamine pool was progressively enriched in its ethan
olamine plasmalogen throughout the development. Chromatographic analys
is of lipid extracts showed the presence of cerebroside traces after 1
6 days of embryo incubation. At hatching, a remarkable increase in non
-hydroxylated cerebrosides was observed concurrently with the appearan
ce of hydroxylated ones. These glycosphingolipids, as well as the sulf
atides, were markedly increased in the lipid extracts of optic lobes o
f adult animals, indicating the progressive development and maturity o
f the myelin sheath.