Most eukaryotic genomes contain substantial portions of repetitive DNA sequences. These are located primarily in highly compacted heterochromatin and, in many cases, are one of the most abundant components of the sex chromosomes. In this sense, the anuran Proceratophrys boiei represents an interesting model for analyses on repetitive sequences by means of cytogenetic techniques, since it has a karyotype with large blocks of heterochromatin and a ZZ/ZW sex chromosome system. The present study describes, for the first time, families of satellite DNA (satDNA) in the frog P. boiei. Its genome size was estimated at 1.6 Gb, of which 41% correspond to repetitive sequences, including satDNAs, rDNAs, transposable elements, and other elements characterized as non-repetitive. The satDNAs were mapped by FISH in the centromeric and pericentromeric regions of all chromosomes, suggesting a possible involvement of these sequences in centromere function. SatDNAs are also present in the W sex chromosome, occupying the entire heterochromatic area, indicating a probable contribution of this class of repetitive DNA to the differentiation of the sex chromosomes in this species. This study is a valuable contribution to the existing knowledge on repetitive sequences in amphibians. We show the presence of repetitive DNAs, especially satDNAs, in the genome of P. boiei that might be of relevance in genome organization and regulation, setting the stage for a deeper functional genome analysis of Proceratophrys.

中文翻译：

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基因组测序揭示了Proceratophrys (Anura, Odontophrynidae) 中大量的卫星 DNA

大多数真核基因组包含大量重复的 DNA 序列。它们主要位于高度紧凑的异染色质中，并且在许多情况下是性染色体中最丰富的成分之一。从这个意义上说，无尾猿 Proceratophrys boiei 代表了一个有趣的模型，用于通过细胞遗传学技术分析重复序列，因为它具有带有大块异染色质和 ZZ/ZW 性染色体系统的核型。本研究首次描述了青蛙 P. boiei 中的卫星 DNA (satDNA) 家族。其基因组大小估计为 1.6 Gb，其中 41% 对应于重复序列，包括 satDNA、rDNA、转座元件和其他特征为非重复的元件。satDNAs 被 FISH 定位在所有染色体的着丝粒和着丝粒周围区域，表明这些序列可能参与着丝粒功能。SatDNA 也存在于 W 性染色体中，占据整个异染色质区域，表明此类重复 DNA 可能对该物种的性染色体分化有贡献。这项研究是对两栖动物重复序列现有知识的宝贵贡献。我们展示了可能与基因组组织和调节相关的 P. boiei 基因组中重复 DNA，尤其是 satDNAs 的存在，为更深入的 Proceratophrys 功能基因组分析奠定了基础。SatDNA 也存在于 W 性染色体中，占据整个异染色质区域，表明此类重复 DNA 可能对该物种的性染色体分化有贡献。这项研究是对两栖动物重复序列现有知识的宝贵贡献。我们展示了可能与基因组组织和调节相关的 P. boiei 基因组中重复 DNA，尤其是 satDNAs 的存在，为更深入的 Proceratophrys 功能基因组分析奠定了基础。SatDNA 也存在于 W 性染色体中，占据整个异染色质区域，表明此类重复 DNA 可能对该物种的性染色体分化有贡献。这项研究是对两栖动物重复序列现有知识的宝贵贡献。我们展示了可能与基因组组织和调节相关的 P. boiei 基因组中重复 DNA，尤其是 satDNAs 的存在，为更深入的 Proceratophrys 功能基因组分析奠定了基础。