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Toronto, Canada

Mastromonaco G.F.,Reproductive Physiology | Houck M.L.,Institute for Conservation Research | Bergfelt D.R.,U.S. Environmental Protection Agency
Sexual Development | Year: 2012

Disorders of sexual development (DSDs) are an increasing concern in both captive and free-ranging wildlife species. Partial or complete reduction in fertility that results from intersex conditions or gonadal dysgenesis is detrimental to the reproductive potential of wildlife populations, and consequently, to their long-term survival. Compared to the wealth of information available on humans and domestic species, a better understanding of the factors influencing sexual development in wildlife is essential for developing and improving population management or conservation plans. This review attempts to bring together the different facets of DSDs as studied in the fields of reproductive physiology, endocrinology, ecotoxicology, wildlife biology, and environmental health. Copyright © 2011 S. Karger AG, Basel. Source

Morden C.-J.C.,Concordia University at Montreal | Weladji R.B.,Concordia University at Montreal | Holand A.,Norwegian University of Life Sciences | Mastromonaco G.,Reproductive Physiology | Nieminen M.,Finnish Game And Fisheries Research Institute
Journal of Wildlife Management | Year: 2011

Proper management of threatened species requires knowledge of population sizes and structures, however current techniques to gather this information are generally impractical and costly and can be stressful on the animals. Non-invasive methods that can produce high quality and accurate results are better alternatives. In winter 2010, we collected blood and fecal samples from 2 reindeer (Rangifer tarandus) populations (Kaamanen, Finland and Svalbard, Norway) to investigate the feasibility of using fecal progesterone metabolites to help estimate the reproductive status, the sex, and the age structures of the populations. We first examined the relationship between plasma progesterone and fecal progesterone metabolite concentrations. We further assessed whether fecal progesterone metabolite levels would clearly differ among calf, yearling, and adult and between pregnant and non-pregnant females. We quantified fecal progesterone metabolites (using enzyme immunoassay) and plasma progesterone (using radio immunoassay) of females and males of different ages from the 2 herds. We found in both populations that fecal progesterone metabolite levels reflected plasma progesterone concentrations. However, the range of fecal progesterone metabolite concentration was much wider in Finland than in Svalbard, possibly due to differences in diet or body condition. We determined a threshold value of 1.31 ng/ml plasma progesterone and 2025.93 ng/g dried fecal progesterone metabolites to identify pregnant reindeer from non-pregnant animals with 100% accuracy. We found a significant difference in fecal progesterone metabolite concentrations only between calves and yearlings/adults in Finland. We could not differentiate among males, non-pregnant adults, or calves of either sex; therefore identification of sex may have to rely on the use of DNA techniques. Our results suggest that hormone concentration, in combination with fecal DNA and pellet morphometry techniques, may provide important population parameters and is a valuable tool for the monitoring of reindeer and may have an application for threatened populations of woodland caribou throughout the winter and early spring. Copyright © 2011 The Wildlife Society. Source

Seaby R.R.,University of Guelph | Mackie P.,Reproductive Physiology | King W.A.,University of Guelph | Mastromonaco G.F.,University of Guelph
Reproduction in Domestic Animals | Year: 2012

Contents: Studies to date have shown that bison embryo development in vitro is compromised with few embryos developing to the blastocyst stage. The aim of this study was to use bison-cattle hybrid embryos, an interspecific cross that is known to result in live offspring in vivo, as a model for assessing species-specific differences in embryo development in vitro. Cattle oocytes fertilized with cattle, plains bison and wood bison sperm were assessed for various developmental parameters associated with embryo quality, including cell number, apoptosis and ATP content. Decreased development to the blastocyst stage was observed in hybrid wood bison embryos compared with the other treatment groups. Although both wood bison and plains bison hybrid blastocysts had significantly lower cell numbers than cattle blastocysts, only wood bison hybrid blastocysts had a greater incidence of apoptosis than cattle blastocysts. Among the treatment groups, ATP levels and expression profiles of NRF1, TFAM, MT-CYB, BAX and BCL2 were not significantly different in both 8- to 16-cell stage and blastocyst stage embryos. These data provide evidence of decreased developmental competence in the wood bison hybrid embryos, owing to inadequate culture conditions that have increased apoptotic events. © 2011 Blackwell Verlag GmbH. Source

Mastromonaco G.F.,Reproductive Physiology | Cantarelli V.I.,National University of Cordoba | Galeano M.G.,National University of Cordoba | Bourguignon N.S.,CONICET | And 2 more authors.
General and Comparative Endocrinology | Year: 2015

The chinchilla is a rodent that bears one of the finest and most valuable pelts in the world. The wild counterpart is, however, almost extinct because of a drastic past and ongoing population decline. The present work was developed to increase our knowledge of the reproductive physiology of pregnancy and post-partum estrus in the chinchilla, characterizing the endocrine patterns of urinary progesterone, estradiol, LH and cortisol metabolites throughout gestation and post-partum estrus and estimating the ovulation timing at post-partum estrus.Longitudinal urine samples were collected once per week throughout pregnancy and analyzed for creatinine, cortisol, LH, estrogen and progesterone metabolite concentrations. To indirectly determine the ovulation timing at post-partum estrus, a second experiment was performed using pregnant females subjected to a post-partum in vivo fertilization scheme. Urinary progestagen metabolites increased above baseline levels in early pregnancy between weeks-8 and -11 respectively to parturition, and slightly declined at parturition time. Urinary estrogens showed rising levels throughout mid- and late pregnancy (weeks-9 to -6 and a further increase at week-5 to parturition) and decreased in a stepwise manner after parturition, returning to baseline levels two weeks thereafter. Cortisol metabolite levels were relatively constant throughout pregnancy with a tendency for higher levels in the last third of gestation and after the pups' birth. Parturition was associated with dramatic reductions in urinary concentrations of sex steroids (especially progestagens). Observations in breeding farms indicated that the females that resulted in a second pregnancy after mating, did so on the second day after parturition. These data were in agreement with an LH peak detected 24. h after parturition. Urinary steroid hormone patterns of estrogen and progestagen metabolites provided valuable information on endocrine events during pregnancy and after parturition in the chinchilla. Results presented in this study enhance our understanding of natural reproductive dynamics in the chinchilla and support empirical observations of breeders that post-partum ovulation occurs ~48. h after parturition. © 2015 Elsevier Inc. Source

Schulte-Hostedde A.I.,Laurentian University | Mastromonaco G.F.,Reproductive Physiology
Evolutionary Applications | Year: 2015

Both natural animal populations and those in captivity are subject to evolutionary forces. Evolutionary changes to captive populations may be an important, but poorly understood, factor that can affect the sustainability of these populations. The importance of maintaining the evolutionary integrity of zoo populations, especially those that are used for conservation efforts including reintroductions, is critical for the conservation of biodiversity. Here, we propose that a greater appreciation for an evolutionary perspective may offer important insights that can enhance the reproductive success and health for the sustainability of captive populations. We provide four examples and associated strategies that highlight this approach, including minimizing domestication (i.e., genetic adaptation to captivity), integrating natural mating systems into captive breeding protocols, minimizing the effects of translocation on variation in photoperiodism, and understanding the interplay of parasites/pathogens and inflammation. There are a myriad of other issues that may be important for captive populations, and we conclude that these may often be species specific. Nonetheless, an evolutionary perspective may mitigate some of the challenges currently facing captive populations that are important from a conservation perspective, including their sustainability. © 2015 The Authors. Source

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