Chromosomal polymorphisms due to heterochromatin growth and pericentric inversions in white‐bellied rat, Niviventer confucianus, from China

摘要

White-bellied rat, Niviventer confucianus (Milne-Edwards, 1871), as one of the harmful rodents in the forest, is widely distributed in China and north part of Thailand and Vietnam (Honacki et al. 1982). Milne-Edwards (1871) first described the samples from Moupin, Sichuan Province of China as Mus confucianus. Allen (1940) transferred it into genus Rattus and divided it into 4 subspecies. Ellerman and Morrison-Scott (1951) considered confucianus as the synonym of niviventer. Lekagul and McNeely (1977) regarded Niviventer as a subgenus of Rattus. Musser (1981) raised these species to a new genus Niviventer according to the morphology and chromosomes. Among 15 species of this genus, 7 species are distributed in China: N. andersoni, N. excelsio, N. eha, N. cremorriventer, N. confucianus, N. fulvescence and N. coxingi. Wang and Zheng (1981) studied white-bellied rat, N. confucianus, in China systematically, and divided it into 6 subspecies. Huang et al. (1995) considered that the species in China should be divided into 8 subspecies, that is conficianus, sacer, chiliensis, lotipes, mentosus, culturaius, naoniuensis and yushuensis. Deng et al. (2000) studied the species distributed in southwestern China using the morphological characteristics and established two new subspecies, yajiangensis and deqinensis. In conclusion, there are 10 subspecies of white-bellied rat, N. confucianus, in China, and the specimens of the species from Shandong and Shaanxi province studied in present work belong to the same subspecies, N. c. sacer, according to Wang and Zheng (1981) and Huang et al. (1995). Chromosomes in some species of this genus had been reported by some researchers, such as N. bukit (Duncan et al. 1970, 1974), N. confucianus (Markvong et al. 1973), N. cremoriventer, N. fulvescens, N. niviventer (Markvong et al. 1972; Yong 1970), N. hinpoon (Marshall 1977), N. lepturus (Duncan et al. 1974) and N. rapit (Yong 1969a,b). Jiang (1995) reported the conventional karyotypes of N. confucianus and N. fulvescens in Guangdong province, southern China. There are still no reports on chromosomes for white-bellied rat, Niviventer confucianus, in other parts of China. Conventional karyotypes, C-banding, G-banding and silver staining karyotypes of N. confucianus from Mt. Tai and Jinan, Shandong Province and Ningshan, Shaanxi Province of China were analyzed in the present study, and also the chromosomal polymorphisms in the populations of the species.