a Departamento de Biotecnologia, Genética e Biologia Celular , Universidade Estadual de Maringá , Maringá , Paraná , Brazil.
b Departamento de Tecnologia , Universidade Estadual de Maringá, campus Umuarama , Umuarama , Paraná , Brazil.
RNA Biol. 2019 Mar;16(3):330-339. doi: 10.1080/15476286.2019.1572439. Epub 2019 Feb 2.
Non-coding Y RNAs and stem-bulge RNAs are homologous small RNAs in vertebrates and nematodes, respectively. They share a conserved function in the replication of chromosomal DNA in these two groups of organisms. However, functional homologues have not been found in insects, despite their common early evolutionary history. Here, we describe the identification and functional characterization of two sbRNAs in Drosophila melanogaster, termed Dm1 and Dm2. The genes coding for these two RNAs were identified by a computational search in the genome of D. melanogaster for conserved sequence motifs present in nematode sbRNAs. The predicted secondary structures of Dm1 and Dm2 partially resemble nematode sbRNAs and show stability in molecular dynamics simulations. Both RNAs are phylogenetically closer related to nematode sbRNAs than to vertebrate Y RNAs. Dm1, but not Dm2 sbRNA is abundantly expressed in D. melanogaster S2 cells and adult flies. Only Dm1, but not Dm2 sbRNA can functionally replace Y RNAs in a human cell-free DNA replication initiation system. Therefore, Dm1 is the first functional sbRNA described in insects, allowing future investigations into the physiological roles of sbRNAs in the genetically tractable model organism D. melanogaster.
非编码 Y RNA 和茎突 RNA 分别是脊椎动物和线虫中的同源小 RNA。它们在这两组生物的染色体 DNA 复制中具有保守功能。然而，尽管昆虫与脊椎动物和线虫具有共同的早期进化历史，但在昆虫中尚未发现其功能同源物。在这里，我们描述了在黑腹果蝇（Drosophila melanogaster）中鉴定和功能表征的两种 sbRNA，分别称为 Dm1 和 Dm2。通过在黑腹果蝇基因组中对存在于线虫 sbRNA 中的保守序列基序进行计算搜索，鉴定了编码这两种 RNA 的基因。Dm1 和 Dm2 的预测二级结构部分类似于线虫 sbRNA，并在分子动力学模拟中显示出稳定性。这两种 RNA 在系统发育上与线虫 sbRNA 的亲缘关系比与脊椎动物 Y RNA 的亲缘关系更近。Dm1，但不是 Dm2 sbRNA 在黑腹果蝇 S2 细胞和成年果蝇中大量表达。只有 Dm1，而不是 Dm2 sbRNA 可以在人类无细胞 DNA 复制起始系统中替代 Y RNA 的功能。因此，Dm1 是在昆虫中描述的第一个功能 sbRNA，允许未来在遗传上可操作的模式生物黑腹果蝇中研究 sbRNA 的生理作用。
