scholarly journals Induced ovulation mimics the time-table of natural development in the stripe-faced dunnart, Sminthopsis macroura and results in the birth of fertile young

Reproduction ◽  
2010 ◽  
Vol 139 (2) ◽  
pp. 419-425 ◽  
Author(s):  
Phil Chi Khang Au ◽  
Angela Nation ◽  
Marissa Parrott ◽  
Lynne Selwood
Keyword(s):  
Captive Breeding ◽  
Induced Ovulation ◽  
Initial Injection ◽  
Time Table ◽  
Serum Gonadotropin ◽  
Sminthopsis Macroura ◽  
Reproductive Females ◽  
Genetic Pool ◽  
Effective Conservation ◽  
Natural Cycles

Induced ovulation maximizes captive breeding success, increasing productivity and facilitating the contribution of otherwise infertile animals to the genetic pool. In marsupials, induced ovulation to produce fertile young is unknown. Here we present an induction protocol efficient in inducing non-cycling and non-reproductive females to cycle, mate, ovulate, and conceive. Ovulation was induced in Sminthopsis macroura using an initial injection of 0.06 IU equine serum gonadotropin (eSG)/g (time 0), followed on day 4 by 0.04 IU eSG/g. Using this induction regime, the timing of follicular and embryonic development mimics natural cycles and results in the birth of viable, fertile young. Response to induction is not significantly affected by animal age, making this protocol an effective conservation tool. We have established a time-table of development following induction, providing a source of precisely timed research material. This is the first induced ovulation protocol in any marsupial to result in demonstrated fertile offspring and to allow the reliable collection of known-age samples during both the follicular phase and the gestation period.

scholarly journals Induced ovulation, mating success and embryonic development in the stripe-faced dunnart, Sminthopsis macroura

Reproduction ◽  
2001 ◽  
pp. 777-783 ◽  
Author(s):  
DE Hickford ◽  
NE Merry ◽  
MH Johnson ◽  
L Selwood
Keyword(s):  
Oocyte Maturation ◽  
Mating Success ◽  
Luteal Phase ◽  
Intermediate Phase ◽  
Corpora Lutea ◽  
Induced Ovulation ◽  
Ovarian Histology ◽  
Sminthopsis Macroura ◽  
Combined Data ◽  
Natural Cycles

Induced ovulation resulting in normal embryos is rare in marsupials. In this study natural and induced ovulations were compared in mature Sminthopsis macroura (n = 122). Comparison of maturation of preovulatory oocytes by ovarian histology and examination of oocytes removed from developing follicles in 12 ovaries of 23 animals receiving 0.058 iu equine serum gonadotrophin (eSG) g(-1) with ovaries of 12 animals undergoing natural cycles showed that oocyte maturation was significantly more irregular when it was induced (P < 0.001). Postovulatory stages were examined by estimating the number of eggs ovulated from ovarian histology, and by counting oviduct and uterine contents recovered after ovulation. S. macroura receiving 0.087 iu eSG g(-1) (n = 34), administered as one (n = 17) or two (n = 17) injections, were significantly (P < 0.05) more likely to ovulate (74%), mate (80%) and have conceptuses (66%) than were animals receiving 0.058 iu eSG g(-1) (12, 53 and 0%, respectively) (n = 17), and the values were similar to those in animals (n = 36) undergoing natural cycles (100, 81 and 56%, respectively). Induced ovulation using 0.087 iu eSG g(-1) yielded significantly (P < 0.05) more oocytes per ovary (20.8 +/- 8.5; combined data) than did ovulation in animals undergoing natural cycles (13.7 +/- 3.2) (ANOVA, t test). The responses of animals induced in different phases of the oestrous cycle with 0.087 iu eSG g(-1) were not significantly different (ANOVA) with respect to the number of corpora lutea per ovary, conceptuses per animal or days to ovulation after injection. However, the proportion of females that responded after receiving 0.058 iu eSG g(-1) in the luteal phase was significantly different from that in animals treated with the same dose in the intermediate phase (P < 0.01) and in non-cyclic females treated with 0.058 iu eSG g(-1) (P < 0.02). The main benefits of the treatment were that normal embryos resulted and that 70-78% of non-cyclic animals could be induced to ovulate.

scholarly journals Induction of ovulation and natural oestrous cycling in the Stripe-faced Dunnart, Sminthopsis macroura

Reproduction ◽  
2007 ◽  
Vol 133 (2) ◽  
pp. 495-502 ◽  
Author(s):  
E Menkhorst ◽  
N Ezard ◽  
L Selwood
Keyword(s):  
Captive Breeding ◽  
Early Morning ◽  
Breeding Programs ◽  
Hormone Injection ◽  
Initial Injection ◽  
Marsupial Species ◽  
Sminthopsis Macroura ◽  
First Time ◽  
Captive Breeding Programs

Induced ovulation allows reproduction by otherwise infertile females, and is ideal for the captive breeding of endangered species where the population is aged or breeding is unsuccessful. A predictable time of ovulation after induction has not yet been achieved in polyovular marsupials. Ovulation was induced in Sminthopsis macroura using an initial injection of 20 IU equine serum gonadotrophin (eSG; Day 0), followed on Day 4 by either 20 IU eSG (n = 25) or 0.5 mg porcine luteinizing hormone (n = 26). I.p. hormone injection was given in the morning or early evening, and reproductive status was established prior to induction. Five non-cyclic animals began to cycle naturally following induction and one gave birth to a litter. The time of ovulation after the 1st injection (7.8 ± 0.9 days) was significantly shorter (P = 0.000) and less variable than the previous study, mimicked the timing of natural cycling, and both natural and induced animals ovulated in the early morning. In vitro oocyte movement through the oviduct, observed for the first time in a marsupial, occurred in pulses. We estimated one group of oocytes could travel the length of the oviduct in 40 min, but it was probably around 4 h. The entire ovulation time (including multiple ovulations) was estimated at 7.5 h. This study has achieved a predictable timing of ovulation after stimulation, and induced noncyclic animals to cycle naturally and give birth, providing a modified methodology for use in captive breeding programs of endangered dasyurid marsupial species with low fecundity.

scholarly journals Frozen–thawed embryo transfers in natural cycles with spontaneous or induced ovulation: the search for the best protocol continues

2016 ◽  
Vol 31 (12) ◽  
pp. 2803-2810 ◽  
Author(s):  
M. Montagut ◽  
S. Santos-Ribeiro ◽  
M. De Vos ◽  
N.P. Polyzos ◽  
P. Drakopoulos ◽  
...  
Keyword(s):  
Induced Ovulation ◽  
Natural Cycles

Some demographics of the extirpation from the wild of eastern barred bandicoots (Perameles gunni) in 1988-91, near Hamilton, Victoria, Australia

1995 ◽  
Vol 22 (3) ◽  
pp. 289 ◽  
Author(s):  
TW Clark ◽  
JP Gibbs ◽  
PW Goldstraw
Keyword(s):  
Captive Breeding ◽  
Wild Population ◽  
Removal Rate ◽  
Small Population ◽  
Demographic Model ◽  
Average Litter Size ◽  
Stochastic Events ◽  
Reproductive Females ◽  
Near Extinction ◽  
Free Ranging

The threatened, free-ranging mainland poplation, of the eastern barred bandicoot in the Hamilton area of Victoria declined to near extinction in late 1992. Demographic changes associated with the decline were monitored from 1988 to 1992. About 200 different animals were captured in 1988,49 in 1989, 16 in 1990, 3 in 1991 and 3 in 1992; capture rates (number of bandicoots captured per trap-night) displayed a similar pattern: 0.5 in 1988,O.l in 1989,0.05 in 1990,0.05 in 1991 and 0.02 in 1992. Observed declines lay within the 5% confidence intervals predicted by a demographic model for a population subjected to a removal rate of 14 animals per three months (the number removed for captive breeding by managers). Removal of bandicoots to stock a captive population hastened the demise of the wild population by about seven years; however, even in the absence of removals of animals, extinction was impending within 5-10 years. Sex ratios were male-biased in all years except 1988; the bias may have resulted from stochastic events. Average litter sizes did not differ between the 1988 population and subsequent populations, except for the 1991 population, in which a predominance of non-reproductive females contributed to a strong decline in average litter size. These demographic trends illustrate how the synergy between stochastic and deterministic forces can rapidly drive a small population to extinction.

scholarly journals Evaluation of different temporal periods between hormone-induced ovulation attempts in the female Fowler’s toad Anaxyrus fowleri

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Emmet L Guy ◽  
Michelle W Martin ◽  
Andrew J Kouba ◽  
Judith A Cole ◽  
Carrie K Kouba
Keyword(s):  
Hormone Therapy ◽  
Egg Production ◽  
Captive Breeding ◽  
Recovery Period ◽  
Seasonal Breeding ◽  
Amphibian Species ◽  
Breeding Programs ◽  
Induced Ovulation ◽  
Captive Breeding Programs ◽  
Fowler's Toad

Abstract Many amphibian species reinitiate the processes of preparing for reproduction (e.g. oogenesis) soon after breeding indicating hormone-induced ovulation could potentially be achieved out-of-season, which would lead to higher annual fecundity compared to mono-seasonal breeding. Such strategies would be beneficial to captive breeding programs for threatened species that are short-lived, have aging populations or need large numbers of offspring to meet reintroduction goals for species recovery. Unfortunately, little is known regarding how female anurans respond to multiple ovulation events within a year, which could lead to higher annual fecundity compared to mono-seasonal breeding. Thus, we evaluated the effect of temporal period between exogenous hormone stimulation events on egg production using the Fowler’s toad Anaxyrus fowleri as a model species. Female toads (n = 21) were administered hormone therapy twice in 1 year with toads randomly assigned to a treatment of either a 4-, 8- or 12-month recovery period between hormone stimulations. Ovulation was induced using two priming doses of human chorionic gonadotropin (100 IU; hCG) 72 h apart, followed by a resolving dose of hCG (500 IU) plus gonadotropin releasing hormone analogue (GnRHa; 15 μg) given 24 h after the second priming injection. Measured response variables include the number of females ovulating after treatment, total number of eggs produced and percent fertilization, neurula and tadpole development. No significant treatment effects were observed for any response variable (P &gt; 0.05). Findings from this study suggest that hormone therapy can be administered in a bufonid species every 4 or 8 months without significantly affecting the number of ovulating females, egg production, fertilization, neurulation or tadpole development. By collecting gametes out-of-season or multiple times throughout the year, captive breeding programs could potentially increase tadpole production for reintroductions as well as extend the breeding window in captivity.

Habitat associations of Rafinesque’s big-eared bats (Corynorhinus rafinesquii) and their lepidopteran prey in bottomland hardwood forests

2013 ◽  
Vol 91 (2) ◽  
pp. 94-101 ◽  
Author(s):  
J.S. Johnson ◽  
M.J. Lacki
Keyword(s):  
Forested Wetlands ◽  
Habitat Associations ◽  
Deciduous Forests ◽  
Home Ranges ◽  
Bottomland Hardwood Forest ◽  
Bottomland Hardwood ◽  
Corynorhinus Rafinesquii ◽  
Bottomland Hardwood Forests ◽  
Reproductive Females ◽  
Effective Conservation

Effective conservation of forest bats requires knowledge of daytime and nocturnal habitat use. Although many bat species use different habitats during the daytime and nighttime hours, these data are rarely collected simultaneously. We radio-tagged 48 adult Rafinesque’s big-eared bats (Corynorhinus rafinesquii (Lesson, 1827)) in a bottomland hardwood forest in Kentucky from 2009 to 2011. We tracked bats to 64 day roosts over 549 bat-days and found bats roosted almost exclusively in trees located in forested wetlands (n = 59; 92%), and that reproductive females established their home ranges closest to these habitats (P < 0.0001). Although few (n = 4; 6%) roosts were located in deciduous forests on drier soils, these forests were important foraging habitats for pregnant females, which foraged closest to these habitats within their home ranges (P = 0.04). Abundance of Lepidoptera differed among habitats (P = 0.03), with higher abundance in deciduous forests and along forest–field edges. Deciduous forests were the only habitat preferentially selected by any lepidopteran family (Notodontidae), and the only habitat not avoided by any family. These data confirm the importance of forested wetlands to the ecology of Rafinesque’s big-eared bat and demonstrate the benefit of proximally located deciduous forests that provide habitat for their moth prey.

The Fine Structure of Rat Granulosa Cell Cultures Correlated with Progestin Secretion

1973 ◽  
Vol 31 ◽  
pp. 552-553
Author(s):  
T. M. Crisp ◽  
F.R. Denys
Keyword(s):  
Fine Structure ◽  
Granulosa Cell ◽  
Cell Cultures ◽  
Single Injection ◽  
Surrounding Medium ◽  
Petri Dish ◽  
Female Rats ◽  
Vaginal Smear ◽  
Immature Female ◽  
Serum Gonadotropin

The purpose of this paper is to present observations on the fine structure of rat granulosa cell cultures grown in the presence of an adenohypophyseal explant and to correlate the morphology of these cells with progestin secretion. Twenty-six day old immature female rats were given a single injection of 5 IU pregnant mares serum gonadotropin (PMS) in order to obtain ovaries with large vesicular follicles. At 66 hrs. post-PMS administration (estrus indicated by vaginal smear cytology), the ovaries were removed and placed in a petri dish containing medium 199 and 100 U penicillin/streptomycin (P/S)/ml. Under a 20X magnification dissecting microscope, some 5-8 vesicular follicles/ovary were punctured and the granulosa cells were expressed into the surrounding medium. The cells were transferred to centrifuge tubes and spun down at 1000 rpm for 5 mins.

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