The onset of neurotrophin and trk mRNA expression in early embryonic tissues of the quail.
To determine the role of neurotrophins on the initial development of the avian embryo, RT-PCR was used to detect when mRNA for nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), and neurotrophin-3 (NT-3), as well as their respective receptors, trkA, trkB, and trkC, is first expressed in the avian embryo. trkA, BDNF, trkB, NT-3, and trkC mRNA were expressed as early as stage 1 ("prestreak" stage), while NGF mRNA was not expressed until later in development (stage 5, "notochord" stage). Microdissection of Embryonic Day 2 quail (stages 12 to 14) and RT-PCR analysis revealed that the neural crest, neural tube, somites, or notochord all expressed some neurotrophin or trk mRNA. Although a neurotrophin and its appropriate receptor were both often present or absent, in several cases they were present individually, suggesting that they might have either local or target-derived actions.
Yao
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Department of Anatomy and Cell Biology, State University of New York, Brooklyn 11203.
Zhang
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Bernd
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D000818:Animals; D001483:Base Sequence; D019208:Brain-Derived Neurotrophic Factor; D003370:Coturnix / Q000196:embryology*; D017931:DNA Primers / Q000737:chemistry; D018507:Gene Expression Regulation, Developmental; D008969:Molecular Sequence Data; D009414:Nerve Growth Factors / Q000235:genetics*; D009419:Nerve Tissue Proteins / Q000235:genetics; D020933:Neurotrophin 3; D012333:RNA, Messenger / Q000235:genetics; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics*; D020801:Receptor, Ciliary Neurotrophic Factor; D020917:Receptor, trkA / Q000235:genetics*; D020812:Receptor, trkC; D017475:Receptors, Nerve Growth Factor / Q000235:genetics*
D019208:Brain-Derived Neurotrophic Factor; D017931:DNA Primers; D009414:Nerve Growth Factors; D009419:Nerve Tissue Proteins; D020933:Neurotrophin 3; D012333:RNA, Messenger; D020801:Receptor, Ciliary Neurotrophic Factor; D017475:Receptors, Nerve Growth Factor; D020794:Receptor Protein-Tyrosine Kinases; D020917:Receptor, trkA; D020812:Receptor, trkC