Universidad Nacional de Misiones, Facultad de Ciencias Exactas Químicas y Naturales, Instituto de Biología Subtropical (CONICET-UNaM), Laboratorio de Genética Evolutiva, Félix de Azara 1552, N3300LQH Posadas, Misiones, Argentina.
Universidad Nacional de Misiones, Facultad de Ciencias Exactas Químicas y Naturales, Félix de Azara 1552, N3300LQH Posadas, Misiones, Argentina.
An Acad Bras Cienc. 2022 Apr 11;94(1):e20200092. doi: 10.1590/0001-3765202220200092. eCollection 2022.
Intending to increase the knowledge about cytogenetics of Physalaemus and the sparsely studied P. gracilis group, we analyzed the karyotypes of P. carrizorum, P. gracilis, P. lisei, and P. sp. aff. gracilis. We studied chromosome morphology, heterochromatin patterns, Ag-NORs location and mapped the repetitive DNA sequence PcP190. All species showed diploid karyotypes composed of 22 bi-armed chromosomes and similar C- bands and Ag-NOR patterns. C-bands were mainly centromeric and pericentromeric; non-centromeric C-bands were detected on the telomeres of pair 1 in P. lisei, although polymorphic, and interstitially on pair 10 of P. gracilis. This last character is useful to distinguish P. gracilis from its sibling species P. sp. aff. gracilis. The Ag-NOR sites were detected on the long arms of chromosome pair 8 but with a variable position among species. Clusters of PcP190 showed centromeric and pericentromeric positions coincident with conspicuous C-bands, on pairs 2 and 9 in P. gracilis and P. sp. aff. gracilis, pair 3 in P. carrizorum, and pair 7 in P. lisei. These results significantly increase the knowledge about Physalaemus cytogenetics and encourage further studies on the satellite PcP190 in other genera of Leiuperinae to better understand its taxonomic distribution and the evolutionary dynamics.
为了增加对 Physalaemus 的细胞遗传学的了解，并对研究较少的 P. gracilis 组进行研究，我们分析了 P. carrizorum、P. gracilis、P. lisei 和 P. sp. aff. gracilis 的染色体组型。我们研究了染色体形态、异染色质模式、Ag-NOR 位置，并对重复 DNA 序列 PcP190 进行了作图。所有物种都显示出二倍体染色体组型，由 22 对双臂染色体组成，并且具有相似的 C 带和 Ag-NOR 模式。C 带主要位于着丝粒和着丝粒周围；在 P. lisei 中，第 1 对的端粒上检测到非着丝粒 C 带，尽管存在多态性，但在 P. gracilis 的第 10 对中存在间位。后一特征可用于将 P. gracilis 与其姊妹种 P. sp. aff. gracilis 区分开来。Ag-NOR 位点位于第 8 对染色体的长臂上，但在物种之间的位置不同。PcP190 的聚类显示出与明显 C 带一致的着丝粒和着丝粒周围位置，在 P. gracilis 和 P. sp. aff. gracilis 的第 2 和第 9 对、P. carrizorum 的第 3 对和 P. lisei 的第 7 对中。这些结果显著增加了对 Physalaemus 细胞遗传学的了解，并鼓励对 Leiuperinae 其他属中的卫星 PcP190 进行进一步研究，以更好地了解其分类分布和进化动态。
