25 research outputs found

    The karyotype of three Brazilian Terrarana frogs (Amphibia, Anura) with evidence of a new Barycholos species

    Get PDF
    A recent substantial rearrangement of the 882 described eleutherodactyline frog species has considerably improved the understanding of their systematics. Nevertheless, many taxonomic aspects of the South American eleutherodactyline species remain unknown and require further investigation using morphological, cytogenetic and molecular approaches. In this work, the karyotypes of the Brazilian species Ischnocnema juipoca (Atibaia and Campos do Jordão, SP), Barycholos cf. ternetzi (Uberlândia, MG, and Porto Nacional, TO), and Pristimantis crepitans (Chapada dos Guimarães and São Vicente, MT) were analyzed using Giemsa staining, Ag-NOR labeling, and C-banding techniques. All individuals had a diploid number of 22 chromosomes, but the Fundamental Numbers were different among species. The herein described low chromosome number of Pristimantis crepitans is unique within this genus, suggesting that cytogenetically this species is not closely related either to its congeneric species or to Ischnocnema. In addition, karyotype differences, mainly in the NOR position, clearly distinguished the two Barycholos populations, besides indicating the existence of a so far undescribed species in this genus. A taxonomic review could clarify the systematic position of P. crepitans and verify the hypothetic new Barycholos species

    Chromosomal similarity between the Scaly-headed parrot (Pionus maximiliani), the Short-tailed parrot (Graydidascalus brachyurus) and the Yellow-faced parrot (Salvatoria xanthops) (Psittaciformes: Aves): a cytotaxonomic analysis

    No full text
    Behavior, morphology, allozyme studies and DNA hybridization and sequencing data all suggest the independent evolution of the Old and New World parrots and support tribe status for the American species, although the phylogenetic relationships within this tribe are still poorly understood. A previous study has shown that the Yellow-faced parrot (Amazona xanthops Spix 1824) exhibits large karyotypic differences compared to the other Amazona species and suggested that this species should be renamed Salvatoria xanthops, although the relationships between S. xanthops and the other New World parrots remain unclear. In the present work, we describe the karyotype of the Scaly-headed parrot (Pionus maximiliani, Kuhl 1820) and the karyotype and C-banding pattern of the Short-tailed parrot (Graydidascalus brachyurus, Kuhl 1820) and compare them to the karyotype and C-banding pattern of S. xanthops, as well as to the karyotypes of other New World parrots. The chromosomal similarity between these three species and the karyotypic differences between them and other New World parrots suggest that G. brachyurus and S. xanthops are sister species and are most closely related to members of the genus Pionus

    Karyotype description of two Neotropical Psittacidae species: the endangered Hyacinth Macaw, Anodorhynchus hyacinthinus, and the Hawk-headed Parrot, Deroptyus accipitrinus (Psittaciformes: Aves), and its significance for conservation plans

    No full text
    Neotropical parrots are among the most threatened groups of birds in the world, and many species are facing extinction in a near future. At the same time, the taxonomic position of many species remains unclear. Karyotype analysis has been used to elucidate the phylogenetic status of many bird groups, also providing important information for both in situ and ex situ conservation plans. The objective of the present study was to describe for the first time the karyotypes of the endangered Hyacinth Macaw, Anodorhynchus hyacinthinus, and of the Hawk-headed Parrot, Deroptyus accipitrinus. A diploid number of 2n = 70 and a karyotype similar to the main pattern previously found for the genera Ara, Cyanopsitta, Aratinga, Propyrrhura, Pionites, Pionopsitta, Nandayus, and Guaruba were found for both species. These karyotype descriptions can be a starting point for the genetic monitoring of these two declining species

    Cytogenetics of three Brazilian species of Eleutherodactylus (Anura, Leptodactylidae) with 22 chromosomes and re-analysis of multiple translocations in E. binotatus

    Get PDF
    In this paper, we provide a cytogenetic analysis of Eleutherodactylus guentheri, E. parvus and E. binotatus. All of the species had a diploid chromosomal number of 2n = 22. The karyotypes of E. guentheri and E. parvus were very similar and differed only slightly in the morphology of pair 2. These two species also had an NOR-bearing secondary constriction on the long arms of pair 6. The karyotype of E. binotatus differed from those of E. guentheri and E. parvus in the morphology and size of the chromosomes, in the number of chromosomal arms, in the NOR location (detected on the short arms of pair 1), and in the pattern of heterochromatin. These results reinforce the differences between E. guentheri and E. binotatus and support the existence of two species group. Five individuals of E. binotatus showed morphs for pairs 2 and 3. These morphs probably arose from the translocation of a segment from one chromosome of pair 3 to a homologue of pair 2. In addition, some mitotic metaphases of E. binotatus showed spontaneous chromosomal breaks which suggested that there were sites of fragility. Meiotic diakinesis showed multiple chromosomal rings, indicating the occurrence of multiple translocations, as previously reported by other investigators. These data suggest that, in addition to fission and fusion, other chromosomal rearrangements were probably involved in the differentiation of the karyotypes of these species of Eleutherodactylus, especially E. binotatus
    corecore