Distribution of two splice variants of the glutamate transporter GLT-1 in the developing rat retina.
The distributions of a carboxyl terminal splice variant of the glutamate transporter GLT-1, referred to as GLT-1B, and the carboxyl terminus of the originally described variant of GLT-1, referred to hereafter as GLT-1 alpha, were examined using specific antisera. GLT-1B was present in the retina at very early developmental stages. Labelling was demonstrable at embryonic day 14, and strong labelling was evident by embryonic day 18. Such labelling was initially restricted to populations of cone photoreceptors, the processes of which extended through the entire thickness of the retina and appeared to make contact with the retinal ganglion cells. During postnatal development the GLT-1B-positive photoreceptor processes retracted to form the outer plexiform layer, and around postnatal day 7, GLT-1B-immunoreactive bipolar cells appeared. The pattern of labelling of bipolar cell processes within the inner plexiform layer changed during postnatal development. Two strata of strongly immunoreactive terminals were initially evident in the inner plexiform layer, but by adulthood these two bands were no longer evident and labelling was restricted to the somata and processes (but not synaptic terminals) of the bipolar cells, as well as the somata, processes, and terminals of cone photoreceptors. By contrast, GLT-1 alpha appeared late in postnatal development and was restricted mainly to a population of amacrine cells, although transient labelling was also associated with punctate elements in the outer plexiform layer, which may represent photoreceptor terminals.
Reye
Peter
P
Department of Physiology and Pharmacology, School of Biomedical Sciences, University of Queensland, Brisbane, Queensland 4072, Australia.
Sullivan
Robert
R
Pow
David V
DV
D000375:Aging / Q000378:metabolism; D017398:Alternative Splicing / Q000502:physiology; D025042:Amacrine Cells / Q000166:cytology / Q000378:metabolism; D000818:Animals; D000831:Animals, Newborn; D002454:Cell Differentiation / Q000502:physiology; D027342:Excitatory Amino Acid Transporter 2 / Q000235:genetics / Q000378:metabolism*; D005333:Fetus; D018698:Glutamic Acid / Q000378:metabolism*; D007150:Immunohistochemistry; D009434:Neural Pathways / Q000166:cytology / Q000378:metabolism; D017729:Presynaptic Terminals / Q000378:metabolism* / Q000648:ultrastructure; D020033:Protein Isoforms; D017434:Protein Structure, Tertiary / Q000502:physiology; D051381:Rats; D011919:Rats, Inbred Strains / Q000196:embryology* / Q000254:growth & development* / Q000378:metabolism; D012160:Retina / Q000196:embryology* / Q000254:growth & development* / Q000378:metabolism; D017949:Retinal Cone Photoreceptor Cells / Q000166:cytology / Q000378:metabolism; D017948:Retinal Rod Photoreceptor Cells / Q000166:cytology / Q000378:metabolism; D009435:Synaptic Transmission / Q000502:physiology
D027342:Excitatory Amino Acid Transporter 2; D020033:Protein Isoforms; D018698:Glutamic Acid