Characterization of the estrous cycle in Galea spixii(Wagler, 1831)

Abstract

RESUMO.-[Caracterização do ciclo estral de Galea spixii (Wagler, 1831).]Os Galea spixii habitam a vegetação semiá-rida da Caatinga, no Nordeste brasileiro. Eles são criados em cativeiro para realização de pesquisas relacionadas a biologia da reprodução. Sendo assim, o objetivo deste trabalho foi caracterizar o ciclo estral de G. spixii para obtenção de informações que melhorem o conhecimento do manejo reprodutivo da espécie em cativeiro. O ciclo estral foi monitorado por citologia esfoliativa vaginal em doze fêmeas adultas. Após a detecção de dois ciclos completos em cada animal, os mesmos foram eutanasiados. Em seguida foi realizado estudo histológico do epitélio vaginal com três fêmeas em cada fase do ciclo estral; cinco foram pareadas com machos para realização do grupo controle e outras três fêmeas foram utilizadas para monitorar a formação e ruptura da membrana de oclusão vaginal. Através de citologia esfoliativa vaginal, constatou-se predomínio de células superficiais em estro, células intermediárias grandes em proestro, células intermediárias pequenas e células parabasais com presença de neutrófilos em diestro e metaestro, respectivamente. O es- The Galea spixii inhabits semiarid vegetation of Caatinga in the Brazilian Northeast. They are bred in captivity for the development of researches on the biology of reproduction. Therefore, the aim of this study is characterize the estrous cycle of G. spixii, in order to provide information to a better knowledge of captive breeding of the species. The estrous cycle was monitored by vaginal exfoliative cytology in 12 adult females. After the detection of two complete cycles in each animal, the same were euthanized. Then, histological study of the vaginal epithelium, with three females in each phase of the estrous cycle was performed; five were paired with males for performing the control group for estrous cycle phases, and three other were used to monitor the formation and rupture of vaginal closure membrane. By vaginal exfoliative cytology, predominance of superficial cells in estrus, large intermediate cells in proestrus, intermediate and parabasal cells, with neutrophils, in diestrus and metestrus respectively was found. Estrus was detected by the presence of spermatozoa in the control group. By histology, greater proliferation of the vaginal epithelium in proestrus was observed. We conclude that the estrous cycle of G. spixii lasts 15.8 ± 1.4 days and that the vaginal closure membrane develops until complete occlusion of the vaginal ostium, breaking after few days. Future studies may reveal the importance of this fact for the reproductive success of this animal. INDEX TERMS: Galea spixii, cavies, female, preservation, reproduction, rodents. Characterization of the estrous cycle in

Adrenal glands of Spix's yellow-toothed cavy (Galea spixii, Wagler, 1831): morphological and morphometric aspects

“…In our previous studies, polyestrous cycles of females lasting 14-19 days (Santos et al, 2015) with development of vaginal closure membrane (Santos et al, 2014a) were found. In other study, cytochrome enzymes P450c17 and P450 aromatase were found in vaginal tissue throughout estrous cycle suggesting a local production of androgen and estrogen hormones (Santos et al, 2014b) in agreement with several studies that have shown a wide variety of different production sites of steroid hormones in different mammalian species (Conley and Hinshelwood, 2001;Conley et al, 2004).…”

“…It is found in semiarid to arid climate region of Brazilian Northeastern (Oliveira et al, 2008) where it is constantly used as an alternative source of protein for inhabitants of this region. For this reason, it is bred in captivity to provide alternative food, preserve the species and to development of a new experimental model (Santos et al, 2015).…”

Conservation of germplasm derived from spix’s yellow-toothed cavies (Galea spixii WAGLER, 1831)

“…In addition, female presents uterine tubes, uterus and two uterine horns with glands, which open into a single cervix, connecting with the vagina through the fornix, and a vulva with a clitoris pierced by the urethra. As a peculiarity, females do not present a vaginal vestibule, but a vaginal occlusion membrane is present (Santos et al, 2015). The female reaches sexual maturity at 55-90 days on average (Larcher, 1981), presenting a continuous poliestric cycle with a mean duration of 15.8 ± 1.4 days (Santos et al, 2015).…”

“…As a peculiarity, females do not present a vaginal vestibule, but a vaginal occlusion membrane is present (Santos et al, 2015). The female reaches sexual maturity at 55-90 days on average (Larcher, 1981), presenting a continuous poliestric cycle with a mean duration of 15.8 ± 1.4 days (Santos et al, 2015). The estrus can lasts from 6 to 11 days, and the predominance of cornified superficial epithelial cells can be highlighted through the vaginal cytological examination (Santos et al, 2015), associated to the presence of preovulatory follicles in the ovaries (Santos et al, 2017).…”

“…The female reaches sexual maturity at 55-90 days on average (Larcher, 1981), presenting a continuous poliestric cycle with a mean duration of 15.8 ± 1.4 days (Santos et al, 2015). The estrus can lasts from 6 to 11 days, and the predominance of cornified superficial epithelial cells can be highlighted through the vaginal cytological examination (Santos et al, 2015), associated to the presence of preovulatory follicles in the ovaries (Santos et al, 2017). Their gestation period lasts 68 days on average, culminating in the birth two to four pups per litter (Larcher, 1981).…”