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).