红翅皱膝蝗减数分裂染色体轴的形成与联会复合体

本文通过延长低渗处理、压片和硝酸银染色技术,对红翅皱膝蝗减数分裂中期Ⅰ染色体轴的形成过程及其联会复合体(Synaptonemal complex,SC)与染色体轴形成的关系进行了研究。我们的结果表明,中期Ⅰ染色体轴是在晚双线期到终变期的过程中逐渐在染色体中形成的。染色体轴形成的动态行为,一方面暗示了这种结构在染色体集缩和维持中期染色体的形态方面起某种重要作用;另一方面说明了轴是染色体中存在的一种真实结构。同时,本文的结果还指出,SC在早双线期到中双线期就解体了,而中期Ⅰ染色体轴是在晚双线期才开始形成。这两种轴结构之间很明显不是连续的。染色体轴的形成与SC的侧轴无直接的相关性。它们是减数分裂染色体中先后出现的两种不同的轴结构。

Formation of Chromatid Cores and Synaptonemal Complexes in Meiotic Chromosomes of Angaracris rhodopa

The formation of metaphase I chromatid cores and the relationship between the synaptonem-al complex (SC) and the formation of Angaracris rhodopa were studied in squashed preparations-with prologed hypotonic pretreatment and a silver staining technique. Our results indicate that the metaphase I chromatid core is gradually formed during the period from late-diplotene to diakinesis. The dynamic behaviour of chromatid core formation suggests that this structure represents a real structural component existing in metaphase chromosomes and that it may play certain important role (s) in the maintenance, stabilization and condensation of chromosomes. Furthermore, the results presented in this paper demonstrate that the SC becomes disassembled from early-diplotene to mid-diplotene, while the formation of the metaphase I chromatid core starts at late-diplotene. Apparently, it is discontinuous between the SC and the chromatid core. The formation of chromatid cores is not directly related to the SC. They are two different axial structures which are formed sequentially in meiotic chromosomes.