Department of Biology, University of Naples Federico II, Via Cinthia, I-80126 Naples, Italy.
Genes (Basel). 2024 Apr 25;15(5):541. doi: 10.3390/genes15050541.
Satellite DNA (sat-DNA) was previously described as junk and selfish DNA in the cellular economy, without a clear functional role. However, during the last two decades, evidence has been accumulated about the roles of sat-DNA in different cellular functions and its probable involvement in tumorigenesis and adaptation to environmental changes. In molluscs, studies on sat-DNAs have been performed mainly on bivalve species, especially those of economic interest. Conversely, in Gastropoda (which includes about 80% of the currently described molluscs species), studies on sat-DNA have been largely neglected. In this study, we isolated and characterized a sat-DNA, here named PcH-sat, in the limpet using the restriction enzyme method, particularly III. Monomeric units of PcH-sat are 179 bp long, AT-rich (58.7%), and with an identity among monomers ranging from 91.6 to 99.8%. Southern blot showed that PcH-sat is conserved in and , while a smeared signal of hybridization was present in the other three investigated limpets (, and ). Dot blot showed that PcH-sat represents about 10% of the genome of , 5% of that of , and 0.3% of that of . FISH showed that PcH-sat was mainly localized on pericentromeric regions of chromosome pairs 2 and 4-7 of (2n = 18). A database search showed that PcH-sat contains a large segment (of 118 bp) showing high identity with a homologous trait of the Nin-SINE transposable element (TE) of the patellogastropod , supporting the hypothesis that TEs are involved in the rising and tandemization processes of sat-DNAs.
卫星 DNA（sat-DNA）以前被描述为细胞经济中的垃圾和自私 DNA，没有明确的功能作用。然而，在过去的二十年中，已经积累了有关 sat-DNA 在不同细胞功能中的作用的证据，以及它可能参与肿瘤发生和适应环境变化的证据。在软体动物中，对 sat-DNA 的研究主要在双壳类物种中进行，特别是那些具有经济意义的物种。相反，在腹足纲动物（包括目前描述的大约 80%的软体动物物种）中，对 sat-DNA 的研究基本上被忽视了。在这项研究中，我们使用限制性内切酶方法从石鳖中分离和鉴定了一种 sat-DNA，命名为 PcH-sat。PcH-sat 的单体单元长 179bp，富含 AT（58.7%），单体之间的同一性范围为 91.6%至 99.8%。Southern 印迹显示 PcH-sat 在石鳖和中保守，而在其他三种研究的石鳖（、和）中存在杂交信号弥散。点印迹显示 PcH-sat 代表的基因组约为的 10%，的 5%，的 0.3%。FISH 显示 PcH-sat 主要定位于染色体对 2 和 4-7 的着丝粒区（2n=18）。数据库搜索显示 PcH-sat 包含一个大的片段（118bp），与 patellogastropod 的 Nin-SINE 转座元件（TE）的同源性状具有高度同一性，支持了 TEs 参与 sat-DNA 的上升和串联化过程的假说。
