Abstract：
Myelin, the insulating sheath that surrounds neuronal axons, is produced by oligodendrocytes in the central nervous system (CNS). This evolutionary innovation, which first appears in jawed vertebrates, enabled rapid transmission of nerve impulses, more complex brains, and greater morphological diversity. Here, we report that RNA-level expression of RNLTR12-int, a retrotransposon of retroviral origin, is essential for myelination. We show that RNLTR12-int-encoded RNA binds to the transcription factor SOX10 to regulate transcription of myelin basic protein (Mbp, the major constituent of myelin) in rodents. RNLTR12-int-like sequences (which we name RetroMyelin) are found in all jawed vertebrates, and we further demonstrate their function in regulating myelination in two different vertebrate classes (zebrafish and frogs). Our study therefore suggests that retroviral endogenization played a prominent role in the emergence of vertebrate myelin.
摘要：
Myelin,围绕神经元轴突的绝缘鞘，由中枢神经系统（CNS）中的少突胶质细胞产生。这种进化创新，它首先出现在下颌脊椎动物中，能够快速传递神经冲动，更复杂的大脑，和更大的形态多样性。这里,我们报道了RNLTR12-int的RNA水平表达，逆转录病毒来源的反转录转座子，对髓鞘形成至关重要。我们显示RNLTR12-int编码的RNA与转录因子SOX10结合以调节髓鞘碱性蛋白的转录（Mbp，啮齿动物中髓磷脂的主要成分）。RNLTR12-int-like序列（我们命名为RetroMyelin）在所有颌骨脊椎动物中发现，我们进一步证明了它们在两种不同脊椎动物（斑马鱼和青蛙）中调节髓鞘形成的功能。因此，我们的研究表明，逆转录病毒内源性在脊椎动物髓鞘的出现中起着重要作用。
