Navegando por Assunto "Dasyprocta"

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Acesso aberto (Open Access)
Anatomical and histological characteristics of teeth in agouti (Dasyprocta prymnolopha Wagler, 1831)
(2013-12) SILVA, Daiane Claydes Baia da; FAGUNDES, Nathália Carolina Fernandes; TEIXEIRA, Francisco Bruno; PENHA, Nelson Elias Abrahão da; SANTANA, Luana de Nazaré da Silva; OLIVEIRA, Ana Cristina Mendes de; LIMA, Rafael Rodrigues
The agouti species Dasyprocta prymnolopha (D. prymnolopha) is a medium-sized rodent, diurnal, and characteristic of northeastern Brazil, south of the Amazon. Several studies have been made on these rodents. However, there is a lack of analysis of masticatory system, in particular morphology of the teeth. Thus, this research seeks to describe anatomical and histological aspects of the agouti teeth. For this purpose, we used adult agouti, in which measurements and descriptions of teeth and dental tissues were made. It was observed that the dental arch of D. prymnolopha comprises of twenty teeth, evenly distributed in the upper and lower arch, being inferior teeth larger than their corresponding higher. The incisors are larger, and between the posterior premolars and molars, there is a gradual increase in length in the anterior-posterior arch. In microscopic examination, a prismatic appearance was observed consisting of enamel prisms arranged in different directions, behind the enamel and dentin with standard tubular dentinal tubules with variable diameter and far between, also showing a sinuous path from the inner portion to the junction with more superficial enamel. Morphological analysis of dental tissues showed that an enamel with structural organization adapted to the act of chewing and high impact dentin compatible with standard tubular function resilience and mechanical damping of masticatory forces, as found in larger animals, confirming the understanding of eating habits that define much of its ecological functions within the ecosystem they inhabit.
Acesso aberto (Open Access)
Determinação de puberdade em cutias (Rodentia:Dasyproctidae) criadas em cativeiro, através da quantificação das células espermatogênicas
(Universidade Federal do Pará, 2002-05-02) FERREIRA, Ana Cássia Sarmento; OHASHI, Otávio Mitio; http://lattes.cnpq.br/5547874183666459
The main objective of this work is to determine the period when puberty and sexual maturity occurs, thus classify the stages of seminiferous epithelium cycles (SEC), the relative frequency of the stages and compute the spermatogenesis efficiency. 7 groups with ages ranging from 4 to 17 months old were used, divided in the following way: G1 (4 and 5 months, n= 4), G2 (6 and 7 months, n= 4), G3 (8 and 9 months, n= 4), G4 (10 and 11 months, n= 3), G5 (12 and 13 months, n= 4), G6 (14 and 15 months, n= 3) and G7 (16 and 17 months, n= 2). The Testis samples were obtained by castration under anesthesia and their Testis samples, after biometrics, were fixed in ALFAC during 24 hours; after that, the samples were submitted to routine histological processing, the tissues obtained then stained in HE. The phases of reproductive development were determined by qualification of spermatogenic cells from 10 cross sections of the seminiferous circular boundary tubular/animal, which were in the stage 1 of SEC, previously characterized by the tubule morphology method, and which presented eight SEC stages. From 20 cross sections of the seminiferous circular tubules/animal that did not present complete spermatogenesis. To determine the relative frequency, 100 cross sections of the seminiferous tubules per animal, that had attained puberty were analyzed. The body and testis weights presented a high significative correlation with age and correlated significantly between themselves. The body and weights testis biometrics increases significantly (P<0.05) until the phase of beginning of sexual maturity. The analyzed groups were classified as pre-pubescent (G1), pre-puberty (G2), puberty (G3), post-pubescent 1 (G4), phase post-pubescent 2 (G5 and G6) and adult (G7). The puberty was reached with 8-9 months. Cell population observed in this phase was significant to the others (P<0.05) from the post-pubescent 1 on it was observed a non significative increase (P<0.05) until the beginning of the sexual maturity, nearby the 16 17 months. The spermatogenic cells presented high significative correlation with testis weights. The tubule diameter increases significantly (P<0.05) among the groups, corresponding to the enlargement of the cells in its interior. This result presented a high significative correlation with testis weights. After 1600 analysis of seminiferous tubules of eight stages characterized by the tubule morphology method, the most frequent inside the seminiferous tubule was 5 followed by 2 and 1, respectively, namely, these stages were founded in 21,2%, 18,8% and 16,8% of the tubules analyzed. After group of stages frequencies, the post meiotic phase, had a higher frequency, and it was not significant to the others.
Acesso aberto (Open Access)
Karyotypic analysis in species of the genus Dasyprocta (Rodentia: Dasyproctidae) found in Brazilian Amazon
(2003-03) RAMOS, Rosemar Silva Luz; VALE, William Gomes; ASSIS, Maria de Fátima Lima
A total of 30 animals of the genus Dasyprocta were cytogenetically studied. They belong to the following species: D. prymnolopha (N=20), D. leporina (N=6), D. fuliginosa (N=1) and Dasyprocta sp. (N=3) (Dasyproctidae, Hystricognathi). Cell suspensions were obtained by peripheral blood culture, besides bone marrow and spleen cells, from D. prymnolopha and D. leporina. The diploid number was 64/65 for all samples. The karyotypes showed similarity, and chromosomal polymorphism was not detected by Giemsa conventional staining and G banding. The constitutive heterochromatin distribution at the pericentromeric region of all the chromosomes was similar in all species. D. prymnolopha, D. leporina and Dasyprocta sp. presented variation in the heterochromatical block size at one of the homologues of the A18 pair. D. fuliginosa presented the heterochromatin uniformly distributed in all chromosomes. There was not variation in the NORs pattern in the species studied.