Hall K J, Parker J S
Department of Botany, School of Plant Sciences, University of Reading, Whiteknights, UK.
Chromosome Res. 1995 Nov;3(7):417-22. doi: 10.1007/BF00713891.
A spontaneous chromosome fission in the plant Hypochoeris radicata has been characterized by Feulgen staining, in situ hybridization of the rDNA probe pTA71 and silver staining for active nucleolus organizing regions. The parental acrocentric chromosome has no detectable ribosomal genes at the centromere, but both fission derivatives possess active NORs at their centric ends. In fission heterozygotes, pachytene configurations studied by synaptonemal complex spreading show that the ribosomal cistrons form short arms on each telocentric which pair together to form a triradial. The paired short arms are associated with the single nucleolus at pachytene. It is proposed that the origin and stabilization of the fission rearrangement involved transposition of rDNA from the nucleolus organizing region of chromosome 3 into the centromeric region of chromosome 1.
通过福尔根染色、rDNA探针pTA71的原位杂交以及活性核仁组织区的银染，对植物皱叶酸模中的一种自发染色体裂变进行了表征。亲代近端着丝粒染色体在着丝粒处没有可检测到的核糖体基因，但两个裂变衍生物在其着丝粒末端都具有活性核仁组织区。在裂变杂合子中，通过联会复合体铺展研究的粗线期构型表明，核糖体顺反子在每个端着丝粒上形成短臂，它们相互配对形成一个三价体。配对的短臂在粗线期与单个核仁相关联。有人提出，裂变重排的起源和稳定涉及rDNA从3号染色体的核仁组织区转座到1号染色体的着丝粒区域。
