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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.


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.


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.


Baxter-Gilbert J.H.,Laurentian University | Riley J.L.,Laurentian University | Mastromonaco G.F.,Reproductive Physiology | Litzgus J.D.,Laurentian University | Lesbarreres D.,Laurentian University
Conservation Physiology | Year: 2014

Conservation biology integrates multiple disciplines to expand the ability to identify threats to populations and develop mitigation for these threats. Road ecology is a branch of conservation biology that examines interactions between wildlife and roadways. Although the direct threats of road mortality and habitat fragmentation posed by roads have received much attention, a clear understanding of the indirect physiological effects of roads on wildlife is lacking. Chronic physiological stress can lower immune function, affect reproductive rates and reduce life expectancy; thus, it has the potential to induce long-lasting effects on populations. Reptiles are globally in decline, and roads are known to have negative effects on reptile populations; however, it is unknown whether individual responses to roads and traffic result in chronic stress that creates an additional threat to population viability. We successfully extracted reliable measures of corticosterone (CORT), a known, commonly used biomarker for physiological stress, from claw trimmings from painted turtles (Chrysemys picta) captured at three study sites (road-impacted site, control site and validation site). Corticosterone levels in claws were evaluated as a measure of chronic stress in turtles because CORT is deposited during growth of the claw and could provide an opportunity to examine past longterm stress levels. While male turtles had higher CORT levels on average than females, there was no difference in the level of CORT between the road-impacted and control site, nor was there a relationship between CORT and turtle body condition. In validating a novel approach for non-invasive measurement of long-term CORT levels in a keratinized tissue in wild reptiles, our study provides a new avenue for research in the field of stress physiology. © The Author 2014.


Mastromonaco G.F.,Reproductive Physiology | Gunn K.,Laurentian University | McCurdy-Adams H.,Laurentian University | Edwards D.B.,Laurentian University | Schulte-Hostedde A.I.,Laurentian University
Conservation Physiology | Year: 2014

Stress levels of individuals are documented using glucocorticoid concentrations (including cortisol) in blood, saliva, urine or faeces, which provide information about stress hormones during a short period of time (minutes to days). In mammals, use of hair cortisol analysis allows for the assessment of prolonged stress over weeks and months and provides information on chronic stress levels without bias associated with handling. Here, we validate hair cortisol analysis in wild rodents using exogenous adrenocorticotrophic hormone (ACTH challenge) and apply the technique to evaluate stress in eastern chipmunks inhabiting logged and natural sites. Chipmunks were subjected to a mark-recapture study and injected weekly with ACTH (Synacthen Depot) or saline, with hair being collected at the conclusion of the challenge. Subsequently, faecal and hair samples were collected from chipmunks occupying logged and natural sites to assess the utility of hair cortisol in comparison with faecal cortisol metabolites. Following extraction, cortisol concentrations were quantified in hair and faecal extracts by enzyme immunoassay. Hair cortisol concentrations were significantly elevated in samples from ACTH-injected chipmunks compared with saline-injected control animals (five times higher). Chipmunks inhabiting logged sites had increased faecal cortisol metabolite concentrations compared with those in natural sites, but no differences were observed in hair cortisol concentrations. Faecal cortisol metabolite levels were positively correlated with hair cortisol levels in chipmunks. Hair cortisol levels reflect changes in circulating cortisol levels and can be used to evaluate the adrenal stress response, and thus stress, in natural populations. Nonetheless, because of the differences in the temporal scale of stress that hair and faeces represent, we caution the use of hair cortisol for detecting differences in physiological stress when comparing individuals within populations and suggest that it is best suited to examining population-level differences. © The Author 2014.


PubMed | Reproductive Physiology and Laurentian University
Type: Journal Article | Journal: Conservation physiology | Year: 2016

Conservation biology integrates multiple disciplines to expand the ability to identify threats to populations and develop mitigation for these threats. Road ecology is a branch of conservation biology that examines interactions between wildlife and roadways. Although the direct threats of road mortality and habitat fragmentation posed by roads have received much attention, a clear understanding of the indirect physiological effects of roads on wildlife is lacking. Chronic physiological stress can lower immune function, affect reproductive rates and reduce life expectancy; thus, it has the potential to induce long-lasting effects on populations. Reptiles are globally in decline, and roads are known to have negative effects on reptile populations; however, it is unknown whether individual responses to roads and traffic result in chronic stress that creates an additional threat to population viability. We successfully extracted reliable measures of corticosterone (CORT), a known, commonly used biomarker for physiological stress, from claw trimmings from painted turtles (Chrysemys picta) captured at three study sites (road-impacted site, control site and validation site). Corticosterone levels in claws were evaluated as a measure of chronic stress in turtles because CORT is deposited during growth of the claw and could provide an opportunity to examine past long-term stress levels. While male turtles had higher CORT levels on average than females, there was no difference in the level of CORT between the road-impacted and control site, nor was there a relationship between CORT and turtle body condition. In validating a novel approach for non-invasive measurement of long-term CORT levels in a keratinized tissue in wild reptiles, our study provides a new avenue for research in the field of stress physiology.


PubMed | Reproductive Physiology and Laurentian University
Type: Journal Article | Journal: Conservation physiology | Year: 2016

Stress levels of individuals are documented using glucocorticoid concentrations (including cortisol) in blood, saliva, urine or faeces, which provide information about stress hormones during a short period of time (minutes to days). In mammals, use of hair cortisol analysis allows for the assessment of prolonged stress over weeks and months and provides information on chronic stress levels without bias associated with handling. Here, we validate hair cortisol analysis in wild rodents using exogenous adrenocorticotrophic hormone (ACTH challenge) and apply the technique to evaluate stress in eastern chipmunks inhabiting logged and natural sites. Chipmunks were subjected to a mark-recapture study and injected weekly with ACTH (Synacthen Depot) or saline, with hair being collected at the conclusion of the challenge. Subsequently, faecal and hair samples were collected from chipmunks occupying logged and natural sites to assess the utility of hair cortisol in comparison with faecal cortisol metabolites. Following extraction, cortisol concentrations were quantified in hair and faecal extracts by enzyme immunoassay. Hair cortisol concentrations were significantly elevated in samples from ACTH-injected chipmunks compared with saline-injected control animals (five times higher). Chipmunks inhabiting logged sites had increased faecal cortisol metabolite concentrations compared with those in natural sites, but no differences were observed in hair cortisol concentrations. Faecal cortisol metabolite levels were positively correlated with hair cortisol levels in chipmunks. Hair cortisol levels reflect changes in circulating cortisol levels and can be used to evaluate the adrenal stress response, and thus stress, in natural populations. Nonetheless, because of the differences in the temporal scale of stress that hair and faeces represent, we caution the use of hair cortisol for detecting differences in physiological stress when comparing individuals within populations and suggest that it is best suited to examining population-level differences.


PubMed | University of Saskatchewan, Reproductive Physiology and Agriculture and Agri Food Canada
Type: | Journal: Theriogenology | Year: 2017

Experiments were conducted in wood bison to determine the effect of additional maturation time on embryo development of invivo matured oocytes. In experiment 1, cumulus-oocyte complexes (COC) were collected 30hours after hCG treatment in superstimulated wood bison, and expanded COC were fertilized immediately or after 4hours of additional invitro maturation. Embryo development was assessed on Days 3, 7, and 8 (Day 0=day of fertilization). No difference in cleavage rate was detected (55.3% vs. 60.5%, P=0.82), but the Day 8 blastocyst rate was higher after an additional 4hours of invitro maturation time (44.7 vs. 18.4%, P = 0.03). In experiment 2, COC were collected at either 30hours or 34hours after hCG treatment. Expanded COC from the 30hours group were fertilized after 4hours of invitro maturation, whereas those from the 34hours group were fertilized immediately. A higher cleavage rate (74.3 vs. 57.0%) and blastocyst rate (54.1 vs. 37.2%) were found in the 34hours group versus the 30hours group (P<0.05). In conclusion, an additional short period of invitro maturation, or an extended period of invivo maturation are beneficial for invitro embryo production in wood bison.


PubMed | CONICET, Reproductive Physiology and National University of Cordoba
Type: Journal Article | Journal: American journal of primatology | Year: 2017

In the last years, the study of how environmental stimuli influence the physiology and specifically the endocrinology of an organism became increasingly important, relying mainly on the quantification of glucocorticoids to monitor animal welfare. Most studies investigating cortisol levels in primates were focused on the impact of social stressors; however, a major concern for the conservation of howler monkeys is the increased habitat fragmentation led by the advancement of the agricultural frontier. We compared fecal cortisol metabolite levels (FGCM) in howler monkeys (Alouatta caraya) living in fragmented and continuous forests of the Argentine humid Chaco region, throughout the warm season (spring-summer). Fecal samples (n=114) were collected from adult individuals, and steroid extracts analyzed with an enzyme immunoassay also validated in this work. Parallel displacement curves were obtained between dilutions of pooled fecal extracts and the cortisol standard curve (rValidation of an enzyme immunoassay and comparison of fecal cortisol metabolite levels in black and gold howler monkeys (Alouatta caraya) inhabiting fragmented and continuous areas of the humid Chaco region, Argentina. Contrary to our initial prediction, no significant differences in Alouatta caraya fecal cortisol metabolite levels were detected; cortisol metabolites were significantly higher in females. Probably, animals adjusted their diet to cope with feeding in degraded habitats, but with new leaves and buds.


PubMed | University of Winnipeg, Reproductive Physiology, Trent University and Macquarie University
Type: | Journal: Conservation biology : the journal of the Society for Conservation Biology | Year: 2016

Although it is well documented that infectious diseases can pose threats to biodiversity, the potential long-term consequences of pathogen exposure on individual fitness and its effects on population viability have rarely been studied. We tested the hypothesis that pathogen exposure causes physiological carry-over effects with a pathogen that is uniquely suited to this question because the infection period is specific and time limited. The fungus Pseudogymnoascus destructans causes white-nose syndrome (WNS) in hibernating bats, which either die due to the infection while hibernating or recover following emergence from hibernation. The fungus infects all exposed individuals in an overwintering site simultaneously, and bats that survive infection during hibernation clear the pathogen within a few weeks following emergence. We quantified chronic stress during the active season, when bats are not infected, by measuring cortisol in bat claws. Free-ranging Myotis lucifugus who survived previous exposure to P. destructans had significantly higher levels of claw cortisol than nave individuals. Thus, cryptic physiological carry-over effects of pathogen exposure may persist in asymptomatic, recovered individuals. If these effects result in reduced survival or reproductive success, they could also affect population viability and even act as a third stream in the extinction vortex. For example, significant increases in chronic stress, such as those indicated here, are correlated with reduced reproductive success in a number of species. Future research should directly explore the link between pathogen exposure and the viability of apparently recovered populations to improve understanding of the true impacts of infectious diseases on threatened populations.

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