Suja J A, Rufas J S
Departamento de Biología, Edificio de Biológicas, Universidad Autónoma de Madrid, Spain.
Chromosome Res. 1994 Sep;2(5):361-8. doi: 10.1007/BF01552795.
We have analysed by means of silver staining the structure of the chromosome axis at the telomeres of meiotic chromosomes in three different grasshopper species. At metaphase I the chromatid axes run the length of the chromatids although they do not reach the chromosome ends. The axes of sister chromatids are associated and show a round differentiation at their distal ends that we have named the 'telochore'. Telochores never contact the chromosome ends: there is always some chromatin beyond them. In late metaphase I bivalents with a distal chiasma, anaphase I and metaphase II half-bivalents and anaphase II chromatids, the axes clearly possess one telochore in each chromosome end. These results seem to indicate that telochores are differentiations of the distal ends of chromatids. We discuss the possible structural significance of telochores according to the current scaffold/radial loop model of chromatin organization of eukaryotic metaphase chromosomes. Additionally, we suggest the possible functional role of the telochore as a nucleoprotein domain forming a protective cap for telomeric DNA.
我们通过银染法分析了三种不同蝗虫减数分裂染色体端粒处染色体轴的结构。在减数第一次分裂中期，染色单体轴贯穿染色单体全长，尽管它们未到达染色体末端。姐妹染色单体的轴相互关联，在其远端呈现出圆形分化，我们将其命名为“端粒粒”。端粒粒从不接触染色体末端：其之外总有一些染色质。在减数第一次分裂后期带有远端交叉的二价体、减数第一次分裂后期以及减数第二次分裂中期的半二价体和减数第二次分裂后期的染色单体中，染色体轴在每个染色体末端显然都有一个端粒粒。这些结果似乎表明端粒粒是染色单体远端的分化结构。我们根据当前真核中期染色体染色质组织的支架/放射环模型讨论了端粒粒可能的结构意义。此外，我们提出端粒粒作为一种核蛋白结构域，可能对端粒DNA形成保护帽具有功能性作用。
