22 research outputs found

    Cytogenetics of a new species of Paratelmatobius cardosoi group (Anura : Leptodactylidae), with the description of an apparent case of pericentric inversion

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    The karyotype of a new species of Paratelmatobius from the P cardosoi group is described. As with other Paratelmatobius and Scythrophrys karyotypes, Paratelmatobius sp. (aff. cardosoi) shows a diploid number of 24 chromosomes, in addition to other similarities with the former karyotypes. The Paratelmatobius sp. (aff. cardosoi) karyotype differs from that of P. cardosoi in the morphology of pair 4, the NOR location and the C-bands in pairs 3 and 8 (exclusive to Paratelmatobius sp.) and those of pairs 7 and 9 (exclusive to P. cardosoi). Both karyotypes also differ in the amount of heterochromatin in pair 1. The presence of interstitial heterochromatin in the long arm of pair 1 and the interstitial C-bands in both arms of chromosome 5 are apparently synapomorphic characters of P. cardosoi and Paratelmatobius sp. (aff. cardosoi), since they are absent in the other Paratelmatobius and Scythrophrys karyotypes. In Paratelmatobius sp. (aff. cardosoi), the nucleolus organizer region is on the short arm of a small metacentric chromosome (pair 9), an arrangement similar to the NOR-bearing chromosome pair in the karyotype of P. poecilogaster and in karyotype 11 of Scythrophrys. A conspicuous heteromorphism unrelated to the sex determining mechanism was also observed and probably arose from a pericentric inversion.241475

    Chromosome evolution in Cophomantini (Amphibia, Anura, Hylinae)

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    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

    NOR Dispersion, Telomeric Sequence Detection in Centromeric Regions and Meiotic Multivalent Configurations in Species of the Aplastodiscus albofrenatus Group (Anura, Hylidae)

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    Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)In the present study, we examined the chromosome number and morphology, heterochromatin pattern, and location of the nucleolar organizer region (NOR) and telomeric sequences in Aplastodiscus albofrenatus, A. arildae, A. ehrhardti and A. eugenioi in order to cytogenetically characterize the Aplastodiscus albofrenatus group. The 4 species analyzed in this study had diploid numbers of 2n = 22 and very similar chromosome morphology. These species could be differentiated based on the distribution and amount of heterochromatin and the location of the nucleolar organizer region (NOR). Six of the 8 A. albofrenatus individuals had an NOR polymorphism previously unknown in anurans since only one of the homologs of pairs 1 and 7 was stained. In the other 2 specimens, the NOR occurred on both homologs of pair 7. In A. ehrhardti, pairs 6 and 10 were stained by the Ag-NOR technique, but only pair 6 was confirmed by in situ hybridization. The NOR was located on pair 10 in A. arildae and on pair 7 in A. eugenioi. In A. albofrenatus and A. arildae, multivalent rings involving NOR-containing chromosomes were observed during prophase I of meiosis. The telomeric probe identified the telomeres in all species and also centromeric regions in the chromosomes of A. albofrenatus and A. arildae, which were coincident with centromeric heterochromatin. The conserved chromosomal morphology seen mainly in the first 7 pairs among species of the A. albofrenatus group suggests that all of these species probably originated from a common ancestral karyotype and that chromosomal rearrangements resulted in karyotype differentiation, with changes in NOR location, as well as telomeric and heterochromatin dispersal. Copyright (C) 2009 S. Karger AG, Basel1264359367Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundo de Apoio a Pesquisa, Ensino e Extensao da Unicamp (FAEPEX) [1454/04]Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)FAPESP [04/10901-6]CNPq [481124/2004-7]Fundo de Apoio a Pesquisa, Ensino e Extensao da Unicamp (FAEPEX) [1454/04

    The taxonomic status of Hyla pulchella joaquini (Anura : Hylidae) with description of its tadpole and vocalization

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    We redescribe Hyla pulchella joaquini and describe its tadpole and vocalization. The taxonomic status of this subspecies is reevaluated; and on the basis of morphology, geographic distribution, and vocalization, we propose the elevation of this subspecies to specific level with the name Hyla joaquini B. Lutz 1968. We also discuss the relationship of H, joaquini within the species groups of H. pulchella Dumeril and Bibron 1841 and H. circumdata (Cope 1871)

    The specialized reproductive mode of the treefrog Aplastodiscus perviridis (Anura : Hylidae)

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    Males of the South American treefrog Aplastodiscus perviridis construct concealed subterranean nests. Using a complex courtship behavior that involves tactile stimuli and vocalizations, males guide the females to the subterranean nests where eggs are laid. Embryos and facultatively oophagous tadpoles (at least in stage 25) stay in subterranean nests until flooding transports them to ponds or streams. This is a rare reproductive mode previously known for few species in the Hyla albosignata and H. albofrenata complexes. Based on similarities of reproductive mode we suggest a monophyletic origin for Aplastodiscus and these complexes of Hyla

    The taxonomic status of Leptodactylus geminus Barrio, 1973

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    The advertisement calls of Leptodactylus geminus, Leptodactylus gracilis, Leptodactylus plaumanni, and Leptodactylus fuscus are analyzed and compared with published reports. Based on calling data and examination of type material, Leptodactylus geminus is synonymized with L, plaumanni. To differentiate between the sibling species L. gracilis and L. plaumanni, fieldwork is needed, including recording of advertisement calls. Reliable identification of red specimens is not possible based on morphology and coloration alone

    Conserved karyotypes in the Hyla pukhella species group (Anura, Hylidae)

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    Cytogenetic analyses were done on specimens of Hyla marginata and on three populations of H. semiguttata differing in morphology and in the physical parameters of their advertisement call, as well as in individuals of Hyla sp. (aff. semiguttata). All specimens had 2n = 24 chromosomes with a morphology very similar to that of other 24-chromosome Hyla species. Hyla semiguttata and H. marginata showed the same C-banding pattern but were distinguished by the location of the NOR on pair 1 in H. semiguttata (in the three populations) and Hyla sp. (aff. semiguttata), and on pair 10 in H. marginata. The H. semiguttata populations did not differ cytogenetically, despite variations in their morphology and advertisement calls. Similarly, H. semiguttata and H. p. joaquini studied previously had identical C-banding patterns and NOR locations, suggesting that they are very closely related

    Cytogenetics of a new species of Paratelmatobius cardosoi group (Anura : Leptodactylidae), with the description of an apparent case of pericentric inversion

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    The karyotype of a new species of Paratelmatobius from the P cardosoi group is described. As with other Paratelmatobius and Scythrophrys karyotypes, Paratelmatobius sp. (aff. cardosoi) shows a diploid number of 24 chromosomes, in addition to other similarities with the former karyotypes. The Paratelmatobius sp. (aff. cardosoi) karyotype differs from that of P. cardosoi in the morphology of pair 4, the NOR location and the C-bands in pairs 3 and 8 (exclusive to Paratelmatobius sp.) and those of pairs 7 and 9 (exclusive to P. cardosoi). Both karyotypes also differ in the amount of heterochromatin in pair 1. The presence of interstitial heterochromatin in the long arm of pair 1 and the interstitial C-bands in both arms of chromosome 5 are apparently synapomorphic characters of P. cardosoi and Paratelmatobius sp. (aff. cardosoi), since they are absent in the other Paratelmatobius and Scythrophrys karyotypes. In Paratelmatobius sp. (aff. cardosoi), the nucleolus organizer region is on the short arm of a small metacentric chromosome (pair 9), an arrangement similar to the NOR-bearing chromosome pair in the karyotype of P. poecilogaster and in karyotype 11 of Scythrophrys. A conspicuous heteromorphism unrelated to the sex determining mechanism was also observed and probably arose from a pericentric inversion
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