Patterned Expression of BDNF and NT-3 in the Retina and Anterior Segment of the Developing Mammalian Eye

• Published in: Investigative ophthalmology & visual science Vol. 40; no. 12; pp. 2996 - 3005
• Main Authors: Bennett, Jeffrey L, Zeiler, Steven R, Jones, Kevin R
• Format: Journal Article
• Language: English
• Published: Rockville, MD ARVO 01.11.1999; Association for Research in Vision and Ophtalmology
• Subjects: Animals; Anterior Eye Segment - embryology; Anterior Eye Segment - growth & development; Anterior Eye Segment - metabolism; beta-Galactosidase - metabolism; Biological and medical sciences; Brain-Derived Neurotrophic Factor - biosynthesis; Cell Differentiation; Embryonic and Fetal Development; Eye - growth & development; Eye and associated structures. Visual pathways and centers. Vision; Fundamental and applied biological sciences. Psychology; Histocytochemistry; Lac Operon; Mice; Mice, Mutant Strains; Neurotrophin 3 - biosynthesis; Retina - embryology; Retina - growth & development; Retina - metabolism; Vertebrates: nervous system and sense organs; Neurotrophin; Rodentia; Retina; Gene expression; Anterior segment; Eye; Visual system; Vertebrata; Mammalia; Mouse; Developmental stage; Brain derived neurotrophic factor; Differentiation
• ISSN: 0146-0404; 1552-5783

The neurotrophins brain-derived neurotrophic factor (BDNF) and neurotrophin-3 (NT-3) are hypothesized to play an important role in vertebrate eye development because of their patterned expression in the developing and adult neuroretina, their regulated response to retinal and optic nerve injury, and the effects of altered neurotrophin signaling on retinal development. To further characterize the role of these neurotrophins in mammalian eye development and maintenance, the pattern of expression of BDNF and NT-3 was analyzed in the developing and mature mouse eye. Using mouse strains in which the reporter gene lacZ, encoding the enzyme beta-galactosidase, was targeted to either the BDNF or NT-3 locus, the expression of BDNF and NT-3 in the eyes of mice heterozygous for these mutations was analyzed by enzyme histochemistry during embryogenesis, postnatal development, and adulthood. BDNF and NT-3 expression were first observed in the inner and outer segments of the developing optic cup at embryonic days 10.5 to 11.5. As the retina matured, BDNF expression was restricted to retinal ganglion cells and a subset of cells in the inner nuclear layer (INL), whereas NT-3 expression was confined to a small subset of cells in the INL and ganglion cell layer. Both neurotrophins were expressed within the developing retinal pigment epithelium. In the anterior segment, BDNF and NT-3 were expressed at high levels in the developing and mature ciliary epithelium. In the lens and cornea, however, these neurotrophins displayed distinct patterns of expression during development and adulthood. BDNF expression was found in the lens epithelium, immature trabecular meshwork, corneal endothelium, and corneal epithelium, whereas NT-3 expression was confined to the corneal epithelium. BDNF and NT-3 exhibit different, yet overlapping, patterns of expression during the development and differentiation of the mouse eye. In addition to the neuroretina, the spatiotemporal expression of BDNF and NT-3 may play an important role in the development and maintenance of the lens, ciliary body, trabecular meshwork, and cornea.