棕鳟（Salmo trutta）的罗伯逊易位和 Ag-NOR 多态性的群体分析。

A population analysis of Robertsonian and Ag-NOR polymorphisms in brown trout (Salmo trutta).

机构信息

Departamento de Biología Fundamental, Area de Genética, Universidad de Santiago, 27002, Lugo, Spain.

出版信息

Theor Appl Genet. 1994 Sep;89(1):105-11. doi: 10.1007/BF00226990.

Abstract

An analysis of Robertsonian polymorphism and variation in the number of active NORs has been carried out in several populations of brown trout (Salmo trutta) from Northwestern Spain. The karyotype of this species appears to be soundly established, and essentially no variation has been found in chromosome number. Interindividual and interpopulation variation in arm number was detected, with figures ranging between 100 and 102 among individuals, and between 100.10 and 100.80 among populations. This variation in arm number is solely attributable to the polymorphism of the short arm of the main NOR-bearing pair 11, which can appear from acrocentric to metacentric in different individuals. Most populations analyzed showed the standard distribution of active NORs previously observed in this species. The Miño drainage basin, and specially the Chamoso population, showed a multi-chromosomal distribution of active NORs, with several new locations, always telomeric. In most cases no concordance was observed between previously detected rDNA sites in S. trutta and the new Ag-NOR locations. This fact suggests a transposition mechanism rather than an activation of silent rDNA sites to explain this multichromosomal NOR pattern.

摘要

对来自西班牙西北部的几个棕鳟（Salmo trutta）群体进行了罗伯逊易位多态性和 NOR 活性数量的变化分析。该物种的核型似乎已经确立，染色体数量基本上没有变化。在个体间和群体间发现了臂数的个体间和群体间变异，个体之间的数字在 100 到 102 之间，群体之间的数字在 100.10 到 100.80 之间。这种臂数的变化仅归因于主要 NOR 携带对 11 的短臂的多态性，在不同个体中，该短臂可以从近端着丝粒到中央着丝粒。大多数分析的群体显示了该物种先前观察到的活性 NOR 的标准分布。米尼奥流域，特别是查莫索（Chamoso）群体，表现出活性 NOR 的多染色体分布，有几个新的位置，总是端粒。在大多数情况下，在 S. trutta 中先前检测到的 rDNA 位点与新的 Ag-NOR 位置之间没有观察到一致性。这一事实表明，一种转位机制而不是沉默 rDNA 位点的激活可以解释这种多染色体 NOR 模式。