Molecular phylogeny and karyotype differentiation in Paratelmatobius and Scythrophrys (Anura, Leptodactylidae)

Abstract

Paratelmatobius and Scythrophrys are leptodactylid frogs endemic to the Brazilian Atlantic forest and their close phylogenetic relationship was recently inferred in an analysis that included Paratelmatobius sp. and S. sawayae. To investigate the interspecific relationships among Paratelmatobius and Scythrophrys species, we analyzed a mitochondrial region (approximately 2.4 kb) that included the ribosomal genes 12S and 16S and the tRNAval in representatives of all known localities of these genera and in 54 other species. Maximum parsimony inferences were done using PAUP* and support for the clades was evaluated by bootstrapping. A cytogenetic analysis using Giemsa staining, C-banding and silver staining was also done for those populations of Paratelmatobius not included in previous cytogenetic studies of this genus in order to assess their karyotype differentiation. Our results suggested Paratelmatobius and Scythrophrys formed a clade strongly supported by bootstrapping, which corroborated their very close phylogenetic relationship. Among the Paratelmatobius species, two clades were identified and corroborated the groups P. mantiqueira and P. cardosoi previously proposed based on morphological characters. The karyotypes of Paratelmatobius sp. 2 and Paratelmatobius sp. 3 described here had diploid chromosome number 2n = 24 and showed many similarities with karyotypes of other Paratelmatobius representatives. The cytogenetic data and the phylogenetic analysis allowed the proposal/corroboration of several hypotheses for the karyotype differentiation within Paratelmatobius and Scythrophrys. Namely the telocentric pair No. 4 represented a synapomorphy of P. cardosoi and Paratelmatobius sp. 2, while chromosome pair No. 5 with interstitial C-bands could be interpreted as a synapomorphy of the P. cardosoi group. The NOR-bearing chromosome No. 10 in the karyotype of P. poecilogaster was considered homeologous to chromosome No. 10 in the karyotype of Scythrophrys sp., chromosome No. 9 in the karyotype of Paratelmatobius sp. 1, chromosome No. 8 in the karyotypes of Paratelmatobius sp. 2 and of Paratelmatobius sp. 3, and chromosome No. 7 in the karyotype of P. cardosoi. A hypothesis for the evolutionary divergence of these NOR-bearing chromosomes, which probably involved events like gain in heteochromatin, was proposed.

Different pathways are involved in the early development of the transient oral apparatus in anuran tadpoles (Anura: Leiuperidae)

“…The family was resurrected by Grant et al (2006) to include the genera Edalorhina, Engystomops, Eupemphix, Physalaemus, Pleurodema, Pseudopaludicola, and Somuncuria. However, conflicting results were obtained in other phylogenetic analyses (Frost et al, 2006;Lourenço et al, 2008) so that the relationships of these taxa with the other Leptodactyliformes (sensu Frost et al, 2006) should be reassessed. We chose this group because it shows remarkable variation in the oral apparatuses of even closely related species, in some cases also involving characters that are not present in the generalized larval oral discs (Fig.…”

Chromosome Banding in Amphibia. XXXI. The Neotropical Anuran Families Centrolenidae and Allophrynidae

“…A study using DNA sequence data from 2 mitochondrial genes (16S + 12S ribosomal RNA) suggests that A. ruthveni is most closely allied to the family Centrolenidae [Austin et al, 2002]. Further molecular phylogenetic studies analyzing the 16S + 12S rRNA genes and the intervening transfer RNA valine gene [Lourenço et al, 2008], or the mitochondrial 16S + 12S rRNA and NADH-1 genes, as well as the nuclear genes c-myc , POMC and RAG-1 [Guayasamin et al, 2008], have confirmed that A. ruthveni is a sister taxon to the family Centrolenidae. This is consistent with Noble [1931] who originally designated A. ruthveni as an edentate centrolenid.…”

The amphibians of São Paulo State, Brazil amphibians of São Paulo

“…However, our knowledge is still incipient, and the total number of species should increase in the upcoming years (e.g., Figure 9 an unnamed new species and Figure 10 a newly described species), as indicated by the species accumulation curve (Figure 8). Fundamentally, this occurs for two reasons: a larger number of researchers working on the subject and the use of new methodologies (e.g., bioacoustics, cytogenetics, and molecular biology) that allow the recognition of cryptic species (e.g., Faivovich et al 2004, Lourenço et al 2007, Toledo et al 2007, Berneck et al 2008.…”