Polytypic and polymorphic cytogenetic variations in the widespread anuran Physalaemus cuvieri (Anura, Leiuperidae) with emphasis on nucleolar organizing regions

We investigated the NOR distribution in ten populations of Physalaemus cuvieri from different regions of Brazil and Argentina. A high variability in NOR pattern was observed and provided a useful tool in grouping several populations. The specimens from the state of Tocantins, northern Brazil, could easily be distinguished from all the other analyzed populations, since its karyotype presented NORs in the chromosome pairs 1,3,4 and 10 (and sometimes also in chromosome 5), and several pericentromeric C-bands. A NOR-site in chromosome 9 characterized three populations from the northeastern region of Brazil. Interestingly, the P. cuvieri populations located in opposite extremes of the geographic distribution had, as a fixed condition, the presence of NORs in 8q int and llp. Besides interpopulational divergences, intrapopulational variability was observed in the number of NORs, except for populations from the states of Bahia and Minas Gerais, which are boundary states respectively in the northeastern and southeastern regions of Brazil. In relation to NOR size, interindividual variations occurred in all Brazilian and Argentinean populations. Additionally, intraindividual variability in NOR size was detected in specimens from Minas Gerais. The data presented herein revealed substantial geographic polytypic variation in P. cuvieri and indicated that a taxonomic reexamination of this species is necessary.

Restriction fragment analysis of the ribosomal DNA of Paratelmatobius and Scythrophrys species (Anura, Leptodactylidae)

Physical maps of the ribosomal RNA gene 28S of species belonging to the genera Paratelmatobius and Scythrophrys were constructed, using five restriction endonucleases. The restriction sites for Bam HI, Bgl II, Bst EII, and Eco RI had similar positions in all species, although there were interspecific differences in the size of the restriction fragments obtained. An additional Pvu II site was found in Scythrophrys specimens from Piraquara (State of Paraná, Brazil) and from Säo Bento do Sul (State of Santa Catarina, Brazil), but not in the Scythrophrys specimens from Rancho Queimado (State of Santa Catarina, Brazil). This finding is in agreement with the hypothesis regarding the existence of two species in the genus Scythrophrys. On the other hand, the extra Bst EII site considered in the literature to be a synapomorphy for the subfamilies Leptodactylinae and Telmatobiinae was not observed in the genera Paratelmatobius and Scythrophrys, which brings new questions about some taxonomic classifications that include Paratelmatobius in Leptodactylinae and Scythrophrys in Telmatobiinae. Interspecific variation was observed in the size of the restriction fragments analyzed and, in the case of group I Scythrophrys, there was also a variation between the individuals of the two populations. These data suggest that sequencing of the rDNA segments studied here may be useful in phylogenetic studies of the genera Paratelmatobius and Scythrophrys