Oecomys cleberi (Locks, 1981)

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 : 54

Oecomys cleberi

There were three different karyotypes for this species that occur in different localities ( Table 8, Fig. 12 ). Karyotype 1: 2n = 80 and FN = 140. Autosomal complement: 31 metacentric and submetacentric pairs, and eight acrocentric pairs. Sex chromosomes: X, a large submetacentric; Y, an acrocentric. C-banding was performed, the X chromosome presented the short arm entirely heterochrmatic and the Y chromosome was entirely heterochromatic ( Suárez-Villota et al. 2017, pp. 12, Fig. 4B ). Karyotype 2: 2n = 80 and FN = 134. Autosomal complement: 28 biarmed pairs, and 11 acrocentric pairs. Sex chromosomes: X, a large submetacentric; Y, a medium 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 an heterochromatic block on the distal region of the long arm ( Suárez-Villota et al. 2017, pp. 12, Fig. 4C ). Karyotype 3: 2n = 80 and FN = 124. Autosomal complement: one large subtelocentric pair, 22 biarmed pairs medium to small decreasing in size, and 16 acrocentric pairs large to small decreasing in size. Sex chromosomes: X, a large submetacentric; Y, a medium acrocentric. C-banding metaphases exhibited blocks of constitutive heterochromatin on the pericentromeric region of the majority of autosomal pairs. The X chromosome presented the short arm entirely heterochromatic. The Y chromosome was almost entirely heterochromatic. Multiple NORs, were localized at the telomeric regions of the short arms of 1-2 medium-small acrocentric pairs ( Andrades-Miranda et al. 2001b, pp. 272, Fig. 2B ).

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 4. Karyotype of Euryoryzomys sp., male with 2n = 58 and FN = 92. (A) Conventional staining (JAP 228); (B) C-banding (JAP 228); (C) G-banding (JAP 228); (D) Metaphase plate after fluorescent in situ hybridization with telomeric probe (left) and DAPI staining (right) (JAP 228), arrows indicate the hybridization of interstitial telomeric sequence.

FIGURE 12. Distribution of diploid and fundamental number of karyotyped specimens of genus Oecomys. (▲) O. auyantepui; (○) O. bicolor; (□) O. cleberi; (■) O. franciscorum; (ê) O. roberti; (l) Oecomys sp. 1; (r) Oecomys sp. 2.