Repetitive DNAs are the main components of eukaryotic genome. We mapped the 18S rDNA and TTAGG telomeric probe sequences by FISH to meiotic chromosomes of eight species of the order Psocoptera considered a basal taxon of Paraneoptera: Valenzuela burmeisteri (Brauer, 1876), Stenopsocus lachlani Kolbe, 1960, Graphopsocus cruciatus (Linnaeus, 1768), Peripsocus phaeopterus (Stephens, 1836), Philotarsus picicornis (Fabricius, 1793), Amphigerontia bifasciata (Latreille, 1799), Psococerastis gibbosa (Sulzer, 1766), and Metylophorus nebulosus (Stephens, 1836). These species belong to five distantly related families of the largest psocid suborder Psocomorpha: Caeciliusidae, Stenopsocidae, Peripsocidae, Philotarsidae, and Psocidae. We show that all the examined species share a similar location of 18S rDNA on a medium-sized pair of autosomes. This is the first study of rDNA clusters in the order Psocoptera using FISH. We also demonstrate that these species have the classical insect (TTAGG)n telomere organization. Our results provide a foundation for further cytogenetic characterization and chromosome evolution studies in Psocoptera.

中文翻译：

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比较FISH映射的核糖体DNA簇和TTAGG端粒序列到8种昆虫鳞翅目昆虫的全动染色体。

重复DNA是真核基因组的主要组成部分。我们通过FISH将18S rDNA和TTAGG端粒探针序列映射到8个物种的鳞翅目减数分裂染色体上，这些鳞翅目被认为是对翅目的基础分类单位：Valenzuela burmeisteri（Brauer，1876），Stenopsocus lachlani Kolbe，1960，Graphopsocus cruciatus（Linnaeus） ，phaipsocus phaeopterus（Stephens，1836），Philotarsus picicornis（Fabricius，1793），Amphigerontia bifasciata（Latreille，1799），Psococerastis gibbosa（Sulzer，1766）和Metylophorus nebulosus（Stephens，1836）。这些物种属于最大的伪亚目Pcomcomorpha的五个远缘科：Ca科，剑齿科，Peripsocidae，Philotarsidae和Psocidae。我们显示所有检查的物种在中等大小的常染色体对上共享18S rDNA的相似位置。这是首次使用FISH对以鳞翅目为序的rDNA簇进行研究。我们还证明了这些物种具有经典昆虫（TTAGG）n端粒组织。我们的结果为进一步在鳞翅目中的细胞遗传学表征和染色体进化研究提供了基础。