Cytogenetic study of Leptodactylus fuscus and L. latrans (Anura: Leptodactylidae) from the semiarid Brazilian Caatinga scrublands

Abstract

Cytogenetic study of Leptodactylus fuscus and L. latrans (Anura: Leptodactylidae) from the semiarid Brazilian Caatinga scrublands. Frogs in the family Leptodactylidae have diploid chromosome numbers ranging from 2n = 18 to 2n = 26, although there is a predominance of 2n = 22 karyotypes. In the present study, 52 specimens of Leptodactylus fuscus and Leptodactylus latrans were obtained from three municipalities (Carira, Poço Redondo, and Tobias Barreto) of the Brazilian state of Sergipe for karyotype analysis using conventional Giemsa staining techniques, and C-and Ag-NOR banding of the chromosomes obtained from the intestinal epithelium. The results of this study show that the individuals analyzed have highly similar karyotypes, with no evidence of any pronounced species-specific markers. However, some differences were observed in the chromosome morphology and C-bands in comparison with the karyotypes described previously for these species, which may represent intraspecific geographic variation in both taxa.Keywords: amphibians, chromosomes, C-bands, Ag-NOR. 126Phyllomedusa -12(2), December 2013 Resumo Análise citogenética de Leptodactylus fuscus e L. latrans (Anura: Leptodactylidae) de áreas de Caatinga do Brasil. A família Leptodactylidae apresenta números diplóides que variam de 2n = 18 a 2n = 26, porém, na maioria dos gêneros descritos na literatura, há uma predominância de cariótipos com 2n = 22. Neste trabalho foram analisados citogeneticamente 52 exemplares de Leptodactylus fuscus e Leptodactylus latrans coletados pela primeira vez no estado de Sergipe, norte do Brasil, nos municípios de Carira, Poço Redondo e Tobias Barreto, por meio de técnicas de coloração convencional, Banda C e Ag-RON, empregadas em preparações do epitélio intestinal. Os dados mostraram que as espécies aqui analisadas apresentaram padrões cariotípicos muito similares, sem evidência de marcadores específicos das espécies. Contudo, algumas variações de morfologia cromossômica e bandas C observadas divergiram de cariótipos já descritos na literatura e podem indicar diferenças cromossômicas geográficas intraespecíficas para ambas as espécies.

Sex chromosomes in the Vizcacheras’ White-lipped frog, Leptodactylus bufonius (Anura, Leptodactylidae)

“…The 2n = 2x = 22 is the widespread chromosome number in Leptodactylidae (Tomatis et al 2009, Targueta et al 2010, Gazoni et al 2012, Vittorazzi et al 2014, Lourenço et al 2015, Cardozo et al 2016 and cites therein), and could be considered the plesiomorphic condition for Leptodactylus. In this genus, 34 species have been cytogenetically analyzed (Brum-Zorrilla & Sáez 1968, Bogart 1974, Heyer & Diment 1974, Silva et al 2000, Amaro-Ghiraldi et al 2004, Arruda & Morielle-Versute 2008, de Oliveira et al 2012, Gazoni et al 2012, 2021, de Oliveira et al 2013, Coelho et al 2015, Gonzalez et al 2016. Only two of them have a different basic chromosome number: L. brevipes (2n = 2x = 20; Gazoni et al 2012Gazoni et al , 2021 and L. silvanimbus (2n = 2x = 24; Amaro-Ghiraldi et al 2006), which would represent autapomorphic character states.…”

“…A recent phylogenetic analysis of Leptodactylus recovered L. bufonius as the sister taxon of L. troglodytes, L. cupreus, and L. mystacinus + L. apepyta, in a clade that is sister of all remaining species of the L. fuscus group (de Sá et al 2014, Schneider et al 2019. In this group, the C-banding pattern is known only for L. mystacinus, L. gracilis, L. plaumanni, L. fuscus, and L. notoaktites (Silva et al 2000, Arruda & Morielle-Versute 2008, de Oliveira et al 2013, in which sexual chromosomes have never been detected. The large number of Leptodactylus species of which C-banding patterns are unknown does not allow us to determine whether the presence of sex chromosomes in L. bufonius corresponds to an autapomorphy or if it is a more extended condition in the L. fuscus group or the entire genus.…”

“…There is a large amount of information about chromosome data in Leptodactylus that covers near half of its 82 recognized species, with a widespread characteristic karyotype of 2n = 2x = 22 and bi-armed chromosomes (FN = 44) (Brum-Zorrilla & Sáez 1968, Bogart 1974, Heyer & Diment 1974, Silva et al 2000, Amaro-Ghiraldi et al 2004, Arruda & Morielle-Versute 2008, de Oliveira et al 2012, Gazoni et al 2018, 2021, de Oliveira et al 2013, Coelho et al 2016, Gonzalez et al 2016). To date, there is a single report of chromosomic sex determination in these frogs, described in L. pentadactylus, with a mechanism involving multiple sex chromosomes (Gazoni et al 2018).…”