Boeskorov G G, Kartavtseva I V, Zagorodniuk I V, Belianin A N, Liapunova E A
Genetika. 1995 Feb;31(2):185-92.
Distribution of nucleolus organizer regions (NORs) in karyotypes was studied in 10 species of wood mice, including Apodemus flavicollis, A. sylvaticus, A. uralensis (= A. microps), A. fulvipectus (= A. falzfeini), A. ponticus, A. hyrcanicus, A. mystacinus, A. agrarius, A. peninsulae, and A. speciosus. Peculiarities of NOR location in karyotypes can be used in interspecific diagnostics of wood mice. Intraspecific polymorphism of A. sylvaticus, A. agrarius, and A. peninsulae in terms of the number of NORs and their localization in chromosomes can serve as evidence for karyological differentiation in certain populations of these species. The minimum number of active NORs in mice of the genus Apodemus is two to four. Two A. flavicollis wood mice with karyotypes containing one small acrocentric B-chromosome (2n = 49) were identified among animals captured in Estonia. In A. peninsulae, B-chromosomes were found among animals captured in the following regions: the vicinity of Kyzyl (one mouse with 17 microchromosomes, 2n = 65); the vicinity of Birakan (two mice with one metacentric chromosome each, 2n = 49); and in the Ussuri Nature Reserve (one mouse with five B-chromosomes, including three metacentric and two dotlike chromosomes; 2n = 65). In the latter animal, the presence of NORs on two metacentric B-chromosomes was revealed; this is the first case of identification of active NORs on extra chromosomes of mammals.
对10种林鼠的核仁组织区（NORs）在核型中的分布进行了研究，这些林鼠包括黄颈姬鼠、森林姬鼠、乌拉尔姬鼠（= 小家姬鼠）、黄胸姬鼠（= 法氏姬鼠）、 Ponticus姬鼠、Hyrcanicus姬鼠、mystacinus姬鼠、黑线姬鼠、半岛姬鼠和华丽姬鼠。NORs在核型中的定位特点可用于林鼠的种间诊断。森林姬鼠、黑线姬鼠和半岛姬鼠在NORs数量及其在染色体上的定位方面的种内多态性，可作为这些物种某些种群核型分化的证据。姬鼠属小鼠中活跃NORs的最小数量为2至4个。在爱沙尼亚捕获的动物中，鉴定出两只黄颈姬鼠，其核型包含一条小的近端着丝粒B染色体（2n = 49）。在半岛姬鼠中，在以下地区捕获的动物中发现了B染色体：克孜勒附近（一只小鼠有17条微染色体，2n = 65）；比拉坎附近（两只小鼠各有一条中着丝粒染色体，2n = 49）；以及乌苏里自然保护区（一只小鼠有5条B染色体，包括3条中着丝粒染色体和2条点状染色体；2n = 65）。在后者的动物中，发现两条中着丝粒B染色体上存在NORs；这是首次在哺乳动物的额外染色体上鉴定出活跃的NORs。
