| 1. |
- Ernfors, P, et al.
(author)
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Developmental and regional expression of beta-nerve growth factor receptor mRNA in the chick and rat.
- 1988
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In: Neuron. - 0896-6273 .- 1097-4199. ; 1:10, s. 983-96
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Journal article (peer-reviewed)abstract
- Hybridization probes from the transmembrane region of the chick NGF receptor (NGF-R) that show high homology with the rat NGF-R were used to demonstrate an abundant 4.5 kb NGF-R mRNA in the chick embryo at E3.5. The level remained high until E12 but decreased to adult levels by E18. The highest levels at E8 were in spinal cord, bursa of Fabricius, gizzard, femoralis muscle, and skin. In situ hybridization to E7 embryos showed high expression of the NGF-R gene in spinal cord, particularly the lateral motor column, and in dorsal root, sympathetic, and nodose ganglia. NGF-R mRNA expression was observed throughout brain development and in all regions of the adult brain, with high levels in cerebellum and septum. Lymphoid tissues of chick and rat also expressed the receptor. The complex and widespread expression of NGF-R mRNA in areas not known to be NGF targets suggests broader functions for NGF.
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| 2. |
- Hallböök, F, et al.
(author)
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Evolutionary studies of the nerve growth factor family reveal a novel member abundantly expressed in Xenopus ovary.
- 1991
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In: Neuron. - 0896-6273 .- 1097-4199. ; 6:5, s. 845-58
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Journal article (peer-reviewed)abstract
- Evolutionary conservation of members of the NGF family in vertebrates was studied by DNA sequence analysis of PCR fragments for NGF, BDNF, and NT-3 from human, rat, chicken, viper, Xenopus, salmon, and ray. The results showed that the three factors are highly conserved from fishes to mammals. Phylogenetic trees reflecting the evolution and speciation of the members of the NGF family were constructed. In addition, the gene for a fourth member of the family, neurotrophin-4 (NT-4), was isolated from Xenopus and viper. The NT-4 gene encodes a precursor protein of 236 amino acids, which is processed into a 123 amino acid mature NT-4 protein with 50%-60% amino acid identity to NGF, BDNF, and NT-3. The NT-4 protein was shown to interact with the low affinity NGF receptor and elicited neurite outgrowth from explanted dorsal root ganglia with no and lower activity in sympathetic and nodose ganglia, respectively. Northern blot analysis of different tissues from Xenopus showed NT-4 mRNA only in ovary, where it was present at levels over 100-fold higher than those of NGF mRNA in heart.
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