Time Course Analysis of Semphorin 3F and Neuropilin-2 Expression in the Mammalian Brain
Semaphorins (Sema) are an abundant and widely expressed family of membrane-associated and secreted proteins that function as growth cues. Semas have been characterized most abundantly in the central nervous system but can be found in most other tissues as well. There are eight classes of Semas. The first and second classes are specific to invertebrates while classes three, four, six, and seven are only found in vertebrates. Class five is found in both vertebrates and invertebrates while "V" class is located only in viruses. Most of the eight classes of Semas act as either chemoattractants or chemorepellents. While some are instrumental in the in vitro extension of neuronal growth cones, others are expressed in a unique and dynamic pattern during nervous system development. Class three Semas is of interest to our lab because some members are expressed in the hippocampus. Specifically, Sema3F is expressed during development of the hippocampus, an old cortical region of the brain that is most often associated with learning and memory. Sema3F signals through the neuropilin (npn) receptor. Since Sema3F is expressed during development, the question of interest for us is does it continue to be expressed post-development? The purpose of this study was to determine if Sema3F and its receptor (npn2) continues to be expressed in the hippocampus throughout the lifespan of the organism. Sema3F and npn2 were localized beginning on the day of birth and analyses continued at predetermined times through adulthood using immunocytochemistry (ICC). These data provided insight into the expression patterns of Sema3F and its receptor following development. Sema 3F is expressed in the hippocampus, cerebrum and the midbrain. Localization of Sema3F and its receptor in the mature hippocampus suggests it may play a role in learning and memory.
Antoinette Yvonne Coleman,
"Time Course Analysis of Semphorin 3F and Neuropilin-2 Expression in the Mammalian Brain"
ETD Collection for Tennessee State University.