Sánchez A, Jiménez R, Burgos M, Stitou S, Zurita F, Díaz de la Guardia R
Departamento de Genética, Facultad de Ciencias, Universidad de Granada, Spain.
Heredity (Edinb). 1995 Jul;75 ( Pt 1):10-6. doi: 10.1038/hdy.1995.98.
Hedgehogs belong to one of the several mammalian taxa in which karyotype differences are based on variations in heterochromatin content. Furthermore, the number and location of nucleolar organizer regions (NORs) can also vary widely. In the present study these cytogenetic features were investigated in the Algerian hedgehog, Erinaceus (Aethechinus) algirus. The heterochromatin and NOR distribution patterns in the karyotype of this species are new among hedgehogs, whereas the euchromatic regions, including their G-band pattern, are similar to those reported by others. In addition, silver staining revealed a cytogenetic feature exclusive to the heterochromatic blocks of E. algirus: their silver staining with standard cytogenetic procedures. Because no similar phenomenon has been described previously in a mammalian species, several hypotheses about the significance and specificity of silver staining to NOR sites are discussed. Finally, the existence of different types of heterochromatin in the species analysed here, lead us to propose that what hedgehogs have inherited from their common ancestor is a mechanism which permits the accumulation of heterochromatin on specific chromosomes, rather than the heterochromatin itself.
刺猬属于几个哺乳动物分类群之一，在这些分类群中，核型差异基于异染色质含量的变化。此外，核仁组织区（NORs）的数量和位置也可能有很大差异。在本研究中，对阿尔及利亚刺猬（Erinaceus (Aethechinus) algirus）的这些细胞遗传学特征进行了研究。该物种核型中的异染色质和NOR分布模式在刺猬中是新发现的，而常染色质区域，包括它们的G带模式，与其他报道的相似。此外，银染揭示了阿尔及利亚刺猬异染色质块特有的细胞遗传学特征：用标准细胞遗传学程序进行银染。由于此前在哺乳动物物种中未描述过类似现象，因此讨论了关于银染对NOR位点的意义和特异性的几种假设。最后，在此分析的物种中存在不同类型的异染色质，这使我们提出，刺猬从其共同祖先继承的是一种机制，该机制允许异染色质在特定染色体上积累，而不是异染色质本身。
