Abstract
Abstract: :
Purpose: Phospholipase D (PLD), a hydrolytic enzyme of phosphatidylcholine, has been reported to play an important role in a novel receptor-mediated signal transduction pathway in the nervous system. This study has been investigated expression patterns of phospholipase D1, an isoform of PLD, in the rat retina during development. Methods: Retinas of embryos at embryonic day (E) 13, 14, 15, 17, and 20, pups at postnatal day (P) 1, 3, 5, 7, 8, and 15, and adult rats of Sprague-Dawley strain were dissected out and processed for immunocytochemistry and Western blot analysis. The expression patterns of PLD1 were compared with those of glutamine synthetase(GS). Results: PLD1 immunoreactivity appeared first in a few neuroblasts by E13. PLD1 immunoreactive primitive ganglion cells, displaced amacrine cells and ganglion cells, and presuming horizontal cells and amacrine cells appeared at E17, P3, P5, and P7, respectively. In addition, faint immunoreactivity appeared in profiled radial glial cells. PLD1 immunoreactivity at P8 was limited to Müller cells and to the outer segment layer of the photoreceptor cells and the expression pattern was conserved to adult retina. Western blot analysis showed relatively high amounts of PLD1 protein at E17 and P3, a decrease at P7, and moderate amounts thereafter P8. Coexpression of PLD1 with GS in the retina appeared after birth in differentiating neurons and shifted to the Müller cells at P8, and thereafter the pattern was maintained. Conclusion: This expression pattern of the PLD1 during development of the retina suggests that PLD1 plays important roles in glutamate associated differentiation of both specific neurons and radial glial cells and in glutamate mediated cellular signaling in the Müller cells.
Keywords: 399 enzymes/enzyme inhibitors • 434 immunohistochemistry • 564 retinal development