Sooretamys Weksler, Percequillo & Voss 2006

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 : 79

Sooretamys Weksler, Percequillo & Voss 2006

Monotypic genus represented by S. angouya (Fischer 1814) , that occur in the Brazilian Atlantic Forest, from Espírito Santo to Rio Grande Sul; in the Argentinean Atlantic Forest (Misiones) and Semideciduous forests (Corrientes, Entre Ríos, Formosa); and in the Paraguayan Atlantic Forest, both on left and right bank of Río Paraguay ( Weksler et al. 2006; Chiquito et al. 2014).

Karyotype: 2n = 58 and FN = 60. Autosomal complement: two small metacentric pairs, and 26 acrocentric pairs large to small decreasing in size. Sex chromosomes: X, a large acrocentric; Y, a small acrocentric ( Andrades-Miranda et al. 2000, pp. 465, Fig. 2A ; Silva & Yonenaga-Yassuda 2004; Di-Nizo et al. 2014). The autosomal heteromorphism leading to 2n = 57 was reported due to a Robertsonian rearrangement involving two acrocentric autosomes in heterozygous condition. Another karyotype was reported with 2n = 60 due to a facultative presence of two small metacentric B chromosomes, these chromosomes were slightly heteromorphic in size, heterochromatic, G-positive although less intensely stained than the darker bands and NOR carrier at the ends of both arms (Silva & Yonenaga-Yassuda 2004). C-banding metaphases exhibited blocks of constitutive heterochromatin on the pericentromeric region of all autosomes. The X chromosome presented pericentromeric heterochromatic blocks. The Y chromosome was entirely heterochromatic ( Andrades-Miranda et al. 2000). G-banding was also performed. Multiple NORs were localized at the telomeric regions of the short arms of small autosomes ( Andrades-Miranda et al. 2000; Silva & Yonenaga-Yassuda 2004).

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.