Full text
| |
| Author(s): |
Eduardo Rondelli Favero
Total Authors: 1
|
| Document type: | Master's Dissertation |
| Press: | Campinas, SP. |
| Institution: | Universidade Estadual de Campinas (UNICAMP). Instituto de Biologia |
| Defense date: | 2008-08-28 |
| Examining board members: |
Shirlei Maria Recco Pimentel;
Carmen Silvia Busin;
Odair Aguiar Junior
|
| Advisor: | Shirlei Maria Recco Pimentel; Ana Cristina Prado Veiga Menoncello |
| Abstract | |
The genus Pseudopaludicola (family Leiuperidae) comprises 12 species of small sized frogs, which are widely distributed in South America. In Brazil, eight species are described within this genus, and several of them are sympatric. The relevant morphological similarities among the Pseudopaludicola species have contributed to the still poor understanding of many aspects of their taxonomy, including inter- and intrageneric relationships. Cytogenetic data on Pseudopaludicola have been restricted to karyotype analyses using conventional Giemsa staining. Variation in intraspecific chromosomal number was described in P. falcipes, ranging from 2n=16 to 2n=20. In the present work, Brazilian Pseudopaludicola species were submitted to cytogenetic analysis aiming at their further characterization and attempting to better understanding the karyotypical evolution of this genus. The analyzed species were Pseudopaludicola falcipes (Porto Alegre, RS), P. ameghini (sensu Cope, 1887) and P. mystacalis (Chapada dos Guimarães, MT), P. mystacalis and P. ternetzi (Uberlândia, MG), P. aff. falcipes I, II, III and IV (respectively from Santa Fé do Sul, Vitória Brasil, Palestina and Icém, SP), P. aff. mystacalis I, II, III and IV (Icém, SP, Barreirinhas, MA, and Urbano Santos, MA), and Pseudopaludicola sp. 1 and sp. 2 (Poconé, MT) and sp. 3 (Santa Terezinha, MT). Metaphases were obtained from suspensions of intestinal epithelium and testicular cells, and stained with Giemsa or submitted to silver staining technique in order to detect the nucleolus organizing regions (Ag-NOR), and C-banding, for heterochromatin localization. The results revealed interspecific chromosomal number variation. In the Pseudopaludicola sp. 1 and 2 specimens (Poconé MT), two distinct karyotypes were identified, respectively with 2n=22 and 2n=16 chromosomes. Within the Pseudopaludicola aff. mystacalis from Icém, SP, the analyzed specimens had 2n=20 and 2n=16 chromosomes, being nominated I and II, respectively. These data clearly indicated two criptic species of Pseudopaludicola within each of those two localities. The P. falcipes and Pseudopaludicola sp.1 (Poconé, MT) had 2n=22 and the NOR was located at the pericentromeric region in the long arm of the pair 8. The species differed in the NOR morphology, which was heteromorphic in P. falcipes and homomorphic in Pseudopaludicola sp.1, as well as in the localization of some C-bands. Pseudopaludicola ameghini (sensu Cope, 1887), P. ternetzi and Pseudopaludicola aff. mystacalis I (Icém, SP) had 2n=20 chromosomes and the NOR was located on the telomeric region in the long arm of the pair 9. The karyotypes of P. ternetzi and P. ameghini differed in the pair 7 morphology and in the heterochromatin distribution pattern. All analyzed specimens of P. mystacalis, P. aff. falcipes I, II, III and IV, P. aff. mystacalis II, III and IV, and Pseudopaludicola sp. 2 and 3, showed 2n=16 chromosomes, which were all metacentric and submetacentric, with the NOR located in the pericentromeric region of the short arm of the pair 4. In several of those specimens, the size heteromorphism of the pair 4 altered, from submetacentric to metacentric, the classification of one of the homologous of that pair. Strong pericentromeric C-bands were detected on the short arm of the pair 1 and on the long arm of the pair 2 in P. mystacalis, P. aff. falcipes I, II, III and IV, P. aff. mystacalis II, III and IV, and Pseudopaludicola sp. 2 and 3. As based on the cytogenetic data, P. ameghini (sensu Cope, 1887), with 2n = 20, and P. mystacalis, with 2n = 16, are distinct taxonomic units, and the specimens formerly identified as P. aff. falcipes and as Pseudopaludicola sp. were indeed cytogenetically closely related to P. mystacalis and not to P. falcipes, which has 2n = 22 chromosomes. Hence, our data suggest that P. ameghini is not a P. mystacalis synonymy and emphasize the importance of a taxonomic review of the genus Pseudopaludicola. (AU) | |