Neacomys dubosti (Voss, Lunde & Simmons, 2001)

Moreira, Camila Do Nascimento, Ventura, Karen, Percequillo, Alexandre Reis & Yonenaga-Yassuda, Yatiyo, 2020, A review on the cytogenetics of the tribe Oryzomyini (Rodentia: Cricetidae: Sigmodontinae), with the description of new karyotypes, Zootaxa 4876 (1), pp. 1-111 : 30

Neacomys dubosti

Karyotype: 2n = 64 and FN = 68. Autosomal complement: three small metacentric pairs, and 28 acrocentric pairs. Sex chromosomes: X, a medium submetacentric; Y, a small acrocentric. C-banding metaphases exhibited blocks of constitutive heterochromatin on the pericentromeric region of all autosomes. The X chromosome presented the short arm entirely heterochromatic. The Y chromosome presented the long arm entirely heterochromatic. G-banding was also performed. FISH with 18s rDNA sequences revealed signals of NOR on the short arm of six acrocentric pairs, and one of these chromosomes also had a NOR on the distal region of the long arm. FISH with telomeric sequences revealed signals exclusively at the ends of all chromosome arms and no interstitial signals were observed ( Silva et al. 2015, pp. 4, Fig. 2C ). According to Silva et al. (2015) this karyotype was similar to N. spinosus reported by Patton et al. (2000) (2n = 64 and FN = 68), except for the morphology of the X chromosome, which was subtelocentric in N. spinosus and submetacentric in N. dubosti . Another diploid number of 62 was reported by Voss et al. (2001) for a sample from Amapá, state of Brazil ( Table 6, Fig. 7 ).

Figures

FIGURE 2. Distribution of diploid and fundamental number of karyotyped specimens of genus Cerradomys. (□) C. akroai; (■) C. goytaca; (ê) C. langguthi; (r) C. maracajuensis; (▲) C. marinhus; (○) C. scotti; (☆) C. subflavus; (l) C. vivoi.

FIGURE 7. Distribution of diploid and fundamental number of karyotyped specimens of genus Neacomys. (♦) N. dubosti; (☆) N. macedoruizi; (r) N. minutus; (○) N. musseri; (■) N. paracou; (l) N. rosalindae; (ê) N. spinosus; (◊) Neacomys sp.; (□) Neacomys sp. 1; (▲) Neacomys sp. 2.