Cytogenetics of two hylid frogs from Brazilian Cerrado.

Cíntia Pelegrineti Targueta,Vinícius Guerra,Priscilla Guedes Gambale,Rogério Pereira Bastos,Daniela de Melo e Silva,Mariana Pires de Campos Telles

doi:10.1590/1678-4685-gmb-2017-0382

Abstract

Cytogenetic data can be useful for taxonomic and phylogenetic studies, as well as to provide information about chromosome evolution. Therefore, it may help design conservation priorities for some threatened species, such as anurans. Herein, we describe the karyotypes of Scinax constrictus and Ololygon centralis, native endemic species from the Brazilian Cerrado. Chromosome preparations for both species were stained with Giemsa for morphological analyses and then impregnated by the Ag-NOR method for localization of the nucleolar organizer region (NOR). Both species had 24 chromosomes, as confirmed by meiotic analyses, which showed 12 bivalents. Chromosome morphologies presented the same pattern for Scinax and Ololygon compared to species already karyotyped in both genera. The NOR was interstitially located in the long arm of pair 7 in S. constrictus, whereas in O. centralis it was found near the centromere in the long arm of pair 1, thus diverging from what is commonly found for other Ololygon species. Therefore, we provide the first description of the karyotype of O. centralis and the first report of the localization of the NOR for the karyotype of both species. Our study increases the cytogenetic knowledge in species of the genera Scinax and Ololygon, and provide support for further studies on the taxonomy, ecology, and evolution of hylid anurans.

Highlights

The tree frog family Hylidae is the richest in number of species among anurans, with 716 described species (Frost, 2018)
The Ololygon species were previously considered to belong to the genus Scinax, in the Scinax catharinae clade, while species that remained in the genus Scinax comprise the Scinax ruber clade
The karyotypes of Scinax and Ololygon analyzed so far are very conservative concerning the diploid number (2n=24), morphological patterns can be discerned among them (Bogart, 1973; Nunes and Fagundes, 2008; Oliveira et al, 2010; Cardozo et al, 2011; Nogueira et al, 2015; Peixoto et al, 2015)

Summary

Introduction

The tree frog family Hylidae is the richest in number of species among anurans, with 716 described species (Frost, 2018). Knowledge on chromosome number and morphology of hylids is still sparse, and in Scinaxinae, only 45 species of the genera Scinax and Ololygon have known karyotypes (Peixoto et al, 2015, 2016).

Results

Conclusion