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Published on: May 29, 2013
Developmental changes in free D-aspartic acid in the chicken embryo and in the neonatal rat
1Nathan S. Kline Institute for Psychiatric Research, Orangeburg, New York 10962.
Insights
D-aspartic acid levels change during development in chickens and rats. Similar patterns were observed in the brain and retina, suggesting conserved developmental roles for this amino acid.
Area of Science:
- Biochemistry
- Developmental Biology
- Neuroscience
Background:
- D-aspartic acid, an amino acid isomer, is found in various tissues.
- Its role in mammalian and avian development is not fully understood.
- Changes in D-aspartic acid levels correlate with developmental stages.
Purpose of the Study:
- To investigate the developmental patterns of free D-aspartic acid in chicken embryos and neonatal rats.
- To compare the changes in D-aspartic acid concentrations across different tissues and species.
- To explore the potential significance of D-aspartic acid during development.
Main Methods:
- Quantification of free D-aspartic acid using chromatographic techniques.
- Analysis of tissue samples from fertilized chicken eggs, chicken embryos (brain, retina), and neonatal rats (brain, retina, and other tissues).
- Measurement of D/L aspartic acid ratios in adult chicken and rat tissues.
Main Results:
- Free D-aspartic acid exhibited distinct temporal maxima in chicken embryo brain (9% D at 11 days) and retina (20% D at 13 days).
- Neonatal rats showed a similar developmental trend, with D-aspartic acid peaking later in the retina (29% D at 7 days) than in the brain.
- Total D-aspartic acid content increased significantly during chicken embryo development, indicating ongoing synthesis or release.
Conclusions:
- Similar developmental patterns of D-aspartic acid changes were observed in phylogenetically distant species (chickens and rats).
- The distinct temporal profiles in brain and retina suggest tissue-specific roles during development.
- D-aspartic acid is actively synthesized or released during embryonic and neonatal development.
Abstract:
Free D-aspartic acid was measured in fertilized chicken eggs, chicken embryos, and neonatal rats. In each tissue examined a maximum value was found at a characteristic time of development. For the chicken embryo brain, the maximum was 9% D at 11 days of incubation; for the retina, 20% D at 13 days of incubation. In the neonatal rat, as in the chicken embryo, D-aspartic acid continued to increase in the retina after that in the brain and other tissues had begun to decline. The maximum, 29% D, was found 7 days after birth. Thus in two phylogenetically distant species, similar developmental patterns of D-aspartic acid change were observed. Some data on similarities between the D/L aspartic acid ratios of adult chicken and rat tissues are also reported. In addition, the total D-aspartic acid content of the egg, including the embryo, increased from 44 nmol at day 1 to 159 nmol at day 12, showing that release from a bound form or de novo synthesis is a continuing process during development.
