Small nuclear RNA (snRNA) is a class of molecules involved in the processing of pre-mRNA and in regulatory cell processes. snRNAs are always associated with a set of specific proteins. The complexes are referred to as small nuclear ribonucleoproteins, and spliceosome U RNAs are their most common snRNA components. The repetitive sequences of U snDNAs have been cytogenetically mapped in several species of Arthropoda, fishes, and mammals; however, their distribution remains unknown in amphibians. Here, we show results of FISH mapping of U2 snDNA repetitive sequences in species of the amphibian genus Leptodactylus to reveal the distribution patterns of this sequence in their karyotypes. The probe hybridized in the metacentric chromosome pair 6 in Leptodactylus fuscus, L. gracilis, L. latrans, L. chaquensis, L. petersii, L. podicipinus, and L. brevipes. A different pattern was observed in L. labyrinthicus with hybridization signals in 4 chromosome pairs. The same localization of U2 gene sequences in most of the species analyzed suggests a relatively conserved pattern and a similarity of the chromosome 6 among these species of Leptodactylus.
Cytogenet Genome Res

中文翻译：

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U2 snDNA在Leptodactylus（Anura，Leptodactylidae）物种中的染色体作图

小核RNA（snRNA）是一类参与前mRNA加工和调控细胞过程的分子。snRNA总是与一组特定蛋白相关。该复合物称为小核糖核糖核蛋白，剪接体U RNA是其最常见的snRNA成分。U snDNA的重复序列已经在节肢动物，鱼类和哺乳动物的几种物种中进行了细胞遗传学定位。然而，它们在两栖动物中的分布仍然未知。在这里，我们显示了两栖鱼类Leptodactylus物种中U2 snDNA重复序列的FISH定位结果，以揭示该序列在其核型中的分布方式。该探针杂交于Leptodactylus fuscus的亚中心染色体对6 ，L. gracilis，L. latrans，L. chaquensis，L. petersii，L. podicipinus和L. brevipes。在阴唇乳酸杆菌中观察到了不同的模式，在4个染色体对中具有杂交信号。在大多数分析的物种中，U2基因序列的相同定位表明在这些物种的Leptodactylylus中相对保守的模式和6号染色体的相似性。
细胞遗传学基因组研究