Molecular cloning of a human gene that is a member of the nerve growth factor family.

Cell death within the developing vertebrate nervous system is regulated in part by interactions between neurons and their innervation targets that are mediated by neurotrophic factors. These factors also appear to have a role in the maintenance of the adult nervous system. Two neurotrophic factors, nerve growth factor and brain-derived neurotrophic factor, share substantial amino acid sequence identity. We have used a screen that combines polymerase chain reaction amplification of genomic DNA and low-stringency hybridization with degenerate oligonucleotides to isolate human BDNF and a human gene, neurotrophin-3, that is closely related to both nerve growth factor and brain-derived neurotrophic factor. mRNA products of the brain-derived neurotrophic factor and neurotrophin-3 genes were detected in the adult human brain, suggesting that these proteins are involved in the maintenance of the adult nervous system. Neurotrophin-3 is also expected to function in embryonic neural development. IMAGES:

发育中的脊椎动物神经系统内的细胞死亡，部分由神经营养因子介导的神经元与其支配靶标之间的相互作用所调控。此类神经营养因子似乎也在成年神经系统的维持过程中发挥作用。两种神经营养因子——神经生长因子（nerve growth factor）与脑源性神经营养因子（brain-derived neurotrophic factor）——具有显著的氨基酸序列同源性。我们采用了一种结合基因组DNA聚合酶链反应（polymerase chain reaction）扩增与简并寡核苷酸低严谨度杂交的筛选方法，成功分离出人类脑源性神经营养因子以及一个与神经生长因子、脑源性神经营养因子均密切相关的人类基因——神经营养素-3（neurotrophin-3）。在成人脑组织中检测到了脑源性神经营养因子与神经营养素-3基因的mRNA转录产物，这提示这些蛋白质参与了成年神经系统的维持过程。神经营养素-3预计也在胚胎神经发育中发挥生理功能。图像：