Preovulatory follicle development and ovulation in the brushtail possum (Trichosurus vulpecula) monitored by repeated laparoscopy

Abstract

The common method for synchronizing oestrus in brushtail possums is by removal of their pouch young (RPY)

Advances in New Zealand mammalogy 1990–2000: Brushtail possum

“…This information is not reviewed here, but readers are directed to Eckery et al (1996), Moore etal. (1997a, b), Crawford et al (1998b), Frankenberg and Selwood (1998), and relevant papers in Lynch (1998), Sutherland (1999), and references therein. Experimental analysis of possum biology has been greatly enhanced by research into improved husbandry protocols, procedures and detailed analyses of responses to stress and adaptation to captivity (Buddie et al 1992;Jolly etal.…”

Birth of Pouch Young after Artificial Insemination in the Tammar Wallaby (Macropus eugenii)1

“…In the tammar, different combinations of anesthetic and laparotomy have a detrimental effect on survival of fetuses in early but not late pregnancy [39]. Similarly, laparoscopy is thought to affect ovulation and egg transport to the oviduct in the possum [2,40]. In our study, compromised sperm transport due to anesthesia may explain the failure of the 14 animals inseminated into the urogenital sinus and anterior vaginal culs de sac.…”

Determination of Steroidogenic Potential of Ovarian Cells of the Brushtail Possum (Trichosurus vulpecula)1

“…Ovaries were collected from six juveniles, i.e., females that were sexually immature based on their body size and pouch development but were independent of their mothers; these animals were likely between 8 and 12 mo old (possums become independent from their mothers at approximately 8 mo of age and usually reach puberty between 12 and 24 mo of age). Ovaries were also collected from six adult animals in the luteal phase and three animals in the late follicular phase, as assessed by the presence of a large (approximately 5 mm) follicle and an enlarged vaginal cul-de-sac at the time of tissue collection; the follicle destined for ovulation is easily identifiable at this stage [21]. Gonads were recovered after administration of an overdose of sodium pentobarbitone (1 ml; Pentobarb 500 [500 mg/ml ]; Chemstock Animal Health, Christchurch, New Zealand) directly into the heart following anesthesia (10 mg per kg of body weight i.m.…”

“…However, preovulatory-size follicles only develop during the follicular phase [5,20] of the estrous cycle. Although numerous healthy and atretic antral follicles are present during the early follicular phase of the estrous cycle, typically only a single follicle is selected for ovulation at each cycle [21]. During the follicular phase, some of the developing antral follicles secrete estradiol, with concentrations appearing to increase as the follicles develop [22], and estradiol appears to be the dominant steroid during this phase of the reproductive cycle [21,23].…”

“…Although numerous healthy and atretic antral follicles are present during the early follicular phase of the estrous cycle, typically only a single follicle is selected for ovulation at each cycle [21]. During the follicular phase, some of the developing antral follicles secrete estradiol, with concentrations appearing to increase as the follicles develop [22], and estradiol appears to be the dominant steroid during this phase of the reproductive cycle [21,23]. Following ovulation, the AY207453 AY207455 a PCR was repeated using 1 l of a 1:10 dilution of the original PCR under the same conditions to obtain product for cloning.…”