The hylid tribe Cophomantini is a diverse clade of Neotropical treefrogs composed of the genera Aplastodiscus, Boana, Bokermannohyla, Hyloscirtus, and Myersiohyla. The phylogenetic relationships of Cophomantini have been comprehensively reviewed in the literature, providing a suitable framework for the study of chromosome evolution. Employing different banding techniques, we studied the chromosomes of 25 species of Boana and 3 of Hyloscirtus; thus providing, for the first time, data for Hyloscirtus and for 15 species of Boana. Most species showed karyotypes with 2n = 2x = 24 chromosomes; some species of the B. albopunctata group have 2n = 2x = 22, and H. alytolylax has 2n = 2x = 20. Karyotypes are all bi-armed in most species presented, with the exception of H. larinopygion (FN = 46) and H. alytolylax (FN = 38), with karyotypes that have a single pair of small telocentric chromosomes. In most species of Boana, NORs are observed in a single pair of chromosomes, mostly in the small chromosomes, although in some species of the B. albopunctata, B. pulchella, and B. semilineata groups, this marker occurs on the larger pairs 8, 1, and 7, respectively. In Hyloscirtus, NOR position differs in the three studied species: H. alytolylax (4p), H. palmeri (4q), and H. larinopygion (1p). Heterochromatin is a variable marker that could provide valuable evidence, but it would be necesserary to understand the molecular composition of the C-bands that are observed in different species in order to test its putative homology. In H. alytolylax, a centromeric DAPI+ band was observed on one homologue of chromosome pair 2. The band was present in males but absent in females, providing evidence for an XX/XY sex determining system in this species. We review and discuss the importance of the different chromosome markers (NOR position, C-bands, and DAPI/CMA3 patterns) for their impact on the taxonomy and karyotype evolution in Cophomantini.
Background: Many amphibian species are negatively affected by habitat change due to anthropogenic activities. Populations distributed over modified landscapes may be subject to local extinction or may be relegated to the remaining—likely isolated and possibly degraded—patches of available habitat. Isolation without gene flow could lead to variability in phenotypic traits owing to differences in local selective pressures such as environmental structure, microclimate, or site-specific species assemblages.Methods: Here, we tested the microevolution hypothesis by evaluating the acoustic parameters of 349 advertisement calls from 15 males from six populations of the endangered amphibian species Proceratophrys moratoi. In addition, we analyzed the genetic distances among populations and the genetic diversity with a haplotype network analysis. We performed cluster analysis on acoustic data based on the Bray-Curtis index of similarity, using the UPGMA method. We correlated acoustic dissimilarities (calculated by Euclidean distance) with geographical and genetic distances among populations.Results: Spectral traits of the advertisement call of P. moratoi presented lower coefficients of variation than did temporal traits, both within and among males. Cluster analyses placed individuals without congruence in population or geographical distance, but recovered the species topology in relation to sister species. The genetic distance among populations was low; it did not exceed 0.4% for the most distant populations, and was not correlated with acoustic distance.Discussion: Both acoustic features and genetic sequences are highly conserved, suggesting that populations could be connected by recent migrations, and that they are subject to stabilizing selective forces. Although further studies are required, these findings add to a growing body of literature suggesting that this species would be a good candidate for a reintroduction program without negative effects on communication or genetic impact.
We describe a new species of Physalaemus assigned to the Physalaemus signifer Clade, and it is morphologically similar to P. rupestris, from the highlands of the Serra do Cipó in the southern Espinhaço Range, State of Minas Gerais, Southeastern Brazil. The new species is diagnosed by using the following combination of character states: presence of an arrow-shaped blotch on the dorsum of body; presence of a median longitudinal light stripe over urostyle region; belly and ventral surface of thigh marbled with dark gray irregularly shaped blotches on a bluish background; absence of reddish coloration over axillary and inguinal regions in live individuals; bright orange dots scattered over head, upper lip, and dorsum of body in live individuals; ventral surface of hand and foot red in live individuals; small size (adult male SVL=16.2–18.2 mm); presence of brown, not divided, nuptial pad in males; END/ED in males ranging from 0.85–0.93; supernumerary tubercles on foot absent; tarsal fold absent; tarsal tubercle absent; texture of posterior region of belly and ventral surface of thigh smooth; advertisement call composed of two note types (note A + B); advertisement call duration of 0.80–1.28 s; note A with ascending amplitude until mid-note then descending towards the end of the note; note B with pulses arranged in 5–7 groups; and dominant frequency of note A from 1734.4–2765.6 Hz and of note B from 1507.3–2859.4 Hz. A phylogenetic analysis based on mitochondrial DNA sequences recovered the new species nested within the Physalaemus deimaticus species group. Additionally, we redescribe the call of Physalaemus rupestris and provide a review of the geographic distribution and conservation status of the species belonging to the P. deimaticus species group.
Background. Many amphibian species are negatively affected by anthropogenic habitat change. Populations distributed over modified landscapes may be subject to local extinction or may be relegated to remaining, likely isolated and possibly degraded, patches of available habitat. Isolation without gene flow can lead to variability in phenotypic traits due to differences in local selective pressures, such as environmental structure, microclimate or site-specific species assemblages. Methods. Here we tested this microevolution hypothesis by evaluating the acoustic parameters of 349 advertisement calls from 15 males representing six populations of the endangered species Proceratophrys moratoi. In addition, we analyzed the genetic distance between populations and the genetic diversity by haplotype network. We carried out a cluster analysis by Bray-Curtis index of similarity using acoustic data by UPGMA method. We correlated acoustic dissimilarities (calculated by Euclidean distance) with geographic and genetic distances among populations. Results. Spectral traits of the advertisement call of P. moratoi presented lower coefficients of variation than did temporal traits both within and among males. Cluster analyses placed individuals without population and geographical distance congruence, but recovered the species topology in relation to sister species. The genetic distance was low among populations: it did not exceed 0.4% for the most distant populations, and was not correlated with acoustic distance. Discussion. Both acoustic features and genetic sequences are highly conserved, suggesting that populations may be connected by recent migrations or that they are subject to stabilizing selective forces. Although future studies are needed, these findings contribute to a growing body of literature suggesting that this species would be a good candidate for a reintroduction program without negative effects on communication or even genetic heritage.
The Morato’s digger toad (Proceratophrys moratoi) inhabits Brazilian moist savannas and is critically endangered due to its very limited geographic distribution, reduced number of isolated populations, and evidence of population decline and local extinctions. With the objective of providing tools for the genetic study of the species, 22 polymorphic microsatellite loci were isolated and screened using DNA extracted from samples of oral mucosa cells obtained from 113 individuals representing five remnant P. moratoi populations in the Brazilian state of São Paulo. These markers presented 2–18 alleles per locus, polymorphism information content (PIC) of 0.02–0.87, observed heterozygosity of 0.02–0.96 and expected heterozygosity of 0.02–0.87. Three of the loci deviated significantly from Hardy–Weinberg equilibrium in one of the populations, possibly due to the presence of null alleles. Significant linkage disequilibrium was also detected between three pairs of loci. The molecular markers developed in this study were able to discriminate each of the individuals sampled (identity analysis). This means that they will be extremely useful for future genetic studies applied to the conservation of P. moratoi, providing a baseline for estimating the levels of genetic diversity, pedigrees, inbreeding, and population structure, which will be essential for the development of effective genetic management programs.
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