RNA Bioinformatics and High-Throughput Analysis, Friedrich Schiller University Jena, 07743 Jena, Germany.
European Virus Bioinformatics Center, 07743 Jena, Germany.
Viruses. 2024 Jul 27;16(8):1210. doi: 10.3390/v16081210.
Bats are ecologically diverse vertebrates characterized by their ability to host a wide range of viruses without apparent illness and the presence of numerous endogenous viral elements (EVEs). EVEs are well preserved, expressed, and may affect host biology and immunity, but their role in bat immune system evolution remains unclear. Among EVEs, endogenous bornavirus-like elements (EBLs) are bornavirus sequences integrated into animal genomes. Here, we identified a novel EBL in the microbat , EBLL-Cultervirus.10-MyoDau (short name is CV.10-MyoDau) that shows protein-level conservation with the L-protein of a (Wuhan sharpbelly bornavirus). Surprisingly, we discovered a transcript on the antisense strand comprising three exons, which we named AMCR-MyoDau. The active transcription in tissues of AMCR-MyoDau, confirmed by RNA-Seq analysis and RT-PCR, highlights its potential role during viral infections. Using comparative genomics comprising 63 bat genomes, we demonstrate nucleotide-level conservation of CV.10-MyoDau and AMCR-MyoDau across various bat species and its detection in 22 and 12 species. To the best of our knowledge, this marks the first occurrence of a conserved EVE shared among diverse bat species, which is accompanied by a conserved antisense transcript. This highlights the need for future research to explore the role of EVEs in shaping the evolution of bat immunity.
蝙蝠是生态多样化的脊椎动物，其特点是能够在没有明显疾病的情况下宿主广泛的病毒，并存在大量内源性病毒元件（EVEs）。EVEs 保存完好，表达，并可能影响宿主的生物学和免疫功能，但它们在蝙蝠免疫系统进化中的作用尚不清楚。在 EVEs 中，内源性 bornavirus 样元件（EBLs）是整合到动物基因组中的 bornavirus 序列。在这里，我们在小蝙蝠中鉴定出一种新型的 EBL，即 EBLL-Cultervirus.10-MyoDau（简称 CV.10-MyoDau），它与一种（武汉尖腹 bornavirus）的 L 蛋白在蛋白质水平上具有保守性。令人惊讶的是，我们在反义链上发现了一个包含三个外显子的转录本，我们将其命名为 AMCR-MyoDau。通过 RNA-Seq 分析和 RT-PCR 证实了 AMCR-MyoDau 在 组织中的活性转录，突出了其在病毒感染过程中的潜在作用。通过包含 63 种蝙蝠基因组的比较基因组学分析，我们证明了 CV.10-MyoDau 和 AMCR-MyoDau 在各种蝙蝠物种中的核苷酸水平保守性，并在 22 种和 12 种物种中检测到了它们。据我们所知，这标志着首次在不同蝙蝠物种中发现保守的 EVE，并且伴随着保守的反义转录本。这凸显了未来研究探索 EVEs 在塑造蝙蝠免疫进化中的作用的必要性。
