Department of Anatomy and Cell Biology, College of Medicine, National Taiwan University, Taipei, Taiwan.
School of Medicine for International Student, College of Medicine, I-Shou University (Yanchao Campus), Kaohsiung, Taiwan.
J Neurosci Res. 2019 Feb;97(2):202-214. doi: 10.1002/jnr.24347. Epub 2018 Nov 2.
It has been reported that the neuronal intermediate filament (IF) α-internexin may plays a role in the formation of the neuronal cytoskeleton during mammalian development. From a phylogenetic viewpoint, zebrafish express inaa and inab as homologs of mammalian α-internexin. However, the distribution patterns of the inaa and inab proteins throughout zebrafish development have not been well-characterized. We generated antibodies specific for zebrafish inaa and inab and analyzed the distribution of these two proteins in developing zebrafish. Inaa was identified in the major subdivisions of embryonic and larval brains as early as 1 day postfertilization (dpf), including the telencephalon, optic tectum, and cerebellum, and inab was also detected in the same regions from 3 dpf to the adult stage. Moreover, we demonstrated for the first time that inaa was distinctively expressed in the photoreceptor-like cells of the pineal gland, where inab was sparsely detected. Besides, the expression of inaa in male adult fish was found to be stable under different photoperiod conditions. Thus, we suggest that inaa is one of useful markers for studies of zebrafish cone photoreceptors not only in the retina but also in the pineal gland. In conclusion, we report that the distribution patterns of inaa and inab are phylogenetically conserved in the telencephalon, optic tectum, and cerebellum. Moreover, inaa and inab had different expression patterns in the pineal gland and retina during zebrafish development. Both inaa and inab are neuronal IFs and their functional roles may be different in various aspects of zebrafish neuronal development.
据报道，神经元中间丝（IF）α-连接蛋白（internexin）在哺乳动物发育过程中可能在神经元细胞骨架的形成中发挥作用。从系统发育的角度来看，斑马鱼表达的 inaa 和 inab 是哺乳动物α-连接蛋白的同源物。然而，inaa 和 inab 蛋白在斑马鱼发育过程中的分布模式尚未得到很好的描述。我们生成了针对斑马鱼 inaa 和 inab 的特异性抗体，并分析了这两种蛋白在发育中的斑马鱼中的分布。inaa 在受精后 1 天（dpf）的胚胎和幼鱼大脑的主要分区中被鉴定出来，包括端脑、视顶盖和小脑，而 inab 也在 3 dpf 到成年阶段的相同区域中被检测到。此外，我们首次证明 inaa 在松果体的光感受器样细胞中特异性表达，而 inab 在其中稀疏表达。此外，在不同光照条件下，成年雄鱼的 inaa 表达是稳定的。因此，我们认为 inaa 是研究斑马鱼视锥细胞的有用标记物之一，不仅在视网膜中，而且在松果体中也是如此。总之，我们报告 inaa 和 inab 的分布模式在端脑、视顶盖和小脑中有系统发育上的保守性。此外，inaa 和 inab 在斑马鱼发育过程中松果体和视网膜中的表达模式不同。inaa 和 inab 都是神经元 IFs，它们在斑马鱼神经元发育的各个方面的功能作用可能不同。
