scholarly journals MHC-associated mate choice under competitive conditions in captive versus wild Tasmanian devils

2019 ◽  
Vol 30 (5) ◽  
pp. 1196-1204 ◽  
Author(s):  
Jenna Day ◽  
Rebecca M Gooley ◽  
Carolyn J Hogg ◽  
Katherine Belov ◽  
Camilla M Whittington ◽  
...  

AbstractMate choice contributes to driving evolutionary processes when animals choose breeding partners that confer genetic advantages to offspring, such as increased immunocompetence. The major histocompatibility complex (MHC) is an important group of immunological molecules, as MHC antigens bind and present foreign peptides to T-cells. Recent studies suggest that mates may be selected based on their MHC profile, leading to an association between an individual’s MHC diversity and their breeding success. In conservation, it may be important to consider mate choice in captive breeding programs, as this mechanism may improve reproductive rates. We investigated the reproductive success of Tasmanian devils in a group housing facility to determine whether increased MHC-based heterozygosity led individuals to secure more mating partners and produce more offspring. We also compared the breeding success of captive females to a wild devil population. MHC diversity was quantified using 12 MHC-linked microsatellite markers, including 11 previously characterized markers and one newly identified marker. Our analyses revealed that there was no relationship between MHC-linked heterozygosity and reproductive success either in captivity or the wild. The results of this study suggest that, for Tasmanian devils, MHC-based heterozygosity does not produce greater breeding success and that no specific changes to current captive management strategies are required with respect to preserving MHC diversity.

2017 ◽  
Author(s):  
Parice A Brandies ◽  
Catherine E Grueber ◽  
Jamie A Ivy ◽  
Carolyn J Hogg ◽  
Professor K Belov

Successful captive breeding programs are crucial to the long-term survival of threatened species. However, pair incompatibility limits sustainability of many captive populations. Understanding whether the drivers of this incompatibility are behavioural or genetic, or a combination of both, is crucial to improving breeding programs. We used twenty-eight years of pairing data from the San Diego Zoo koala colony, plus genetic analyses using both MHC-linked and non-MHC-linked microsatellite markers, to show that both behavioural and genetic determinants can influence mating success. Male age was reconfirmed to be a contributing factor to the likelihood of a pair copulating. Familiarity was also reconfirmed to increase the probability of a successful copulation. Our data provided evidence that females select mates based on MHC and genome-wide similarity. Male heterozygosity at class II MHC loci influenced both pre- and post-copulatory female choice. Genome-wide similarity and similarity at the MHCII DAB locus were also found to influence female choice at the post-copulatory level. Finally, certain MHC-linked alleles were associated with increased or decreased mating success. We predict that utilising a variety of behavioural and MHC-dependent mate choice mechanisms improves female fitness through increased reproductive success. This study highlights the complexity of mate choice mechanisms within a species and the importance of ascertaining mate choice mechanisms to improve the success of captive breeding programs.


2021 ◽  
Author(s):  
Pauline ML van Leeuwen ◽  
Albrecht I. Schulte-Hostedde ◽  
Christine Fournier-Chambrillon ◽  
Carmen M. Aranda ◽  
Laurie Berthomieu ◽  
...  

Abstract Host’s fitness can be affected by its genotype and gut microbiota, defined as the microbes living in the host’s intestinal tract. This study explored how the genetic diversity of the host influences its bacterial communities in the context of captive breeding programs, for the critically endangered European mink (Mustela lutreola). As stated by the ecosystem on a leash model, loss of host genetic diversity may lead to changes in immunomodulation and will therefore induce modifications of the gut microbiota. We investigated variation in the gut bacteria through 16S rRNA metabarcoding, related to the genetic diversity of European mink held in captivity in two breeding centers representing separate breeding stocks originating from the western and eastern populations. The genetic diversity of the host was assessed through diversity analysis of the adaptive MHC class I and II genes as well as neutral microsatellite markers. Results indicate lower diversity in neutral and MHC class I genes for the western population, and the opposite for MHC class II. A lower MHC class II gene variability led to an increase in microbial phylogenetic diversity and in abundance depending on the presence of specific MHC-II motifs. Those results seem to be linked to management practices that differs between the two programs, especially the number of generations in captivity. Long term Ex situ conservation practices can thus modulate gut microbial communities, that might potentially have consequences on the survival of reintroduced animals. We suggest strategies to foster genetic diversity in captive breeding program to mitigate the effects of genetic drift on those small, isolated populations.


2017 ◽  
Author(s):  
Parice A Brandies ◽  
Catherine E Grueber ◽  
Jamie A Ivy ◽  
Carolyn J Hogg ◽  
Professor K Belov

Successful captive breeding programs are crucial to the long-term survival of threatened species. However, pair incompatibility limits sustainability of many captive populations. Understanding whether the drivers of this incompatibility are behavioural or genetic, or a combination of both, is crucial to improving breeding programs. We used twenty-eight years of pairing data from the San Diego Zoo koala colony, plus genetic analyses using both MHC-linked and non-MHC-linked microsatellite markers, to show that both behavioural and genetic determinants can influence mating success. Male age was reconfirmed to be a contributing factor to the likelihood of a pair copulating. Familiarity was also reconfirmed to increase the probability of a successful copulation. Our data provided evidence that females select mates based on MHC and genome-wide similarity. Male heterozygosity at class II MHC loci influenced both pre- and post-copulatory female choice. Genome-wide similarity and similarity at the MHCII DAB locus were also found to influence female choice at the post-copulatory level. Finally, certain MHC-linked alleles were associated with increased or decreased mating success. We predict that utilising a variety of behavioural and MHC-dependent mate choice mechanisms improves female fitness through increased reproductive success. This study highlights the complexity of mate choice mechanisms within a species and the importance of ascertaining mate choice mechanisms to improve the success of captive breeding programs.


PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5438 ◽  
Author(s):  
Parice A. Brandies ◽  
Catherine E. Grueber ◽  
Jamie A. Ivy ◽  
Carolyn J. Hogg ◽  
Katherine Belov

Successful captive breeding programs are crucial to the long-term survival of many threatened species. However, pair incompatibility (breeding failure) limits sustainability of many captive populations. Understanding whether the drivers of this incompatibility are behavioral, genetic, or a combination of both, is crucial to improving breeding programs. We used 28 years of pairing data from the San Diego Zoo koala colony, plus genetic analyses using both major histocompatibility complex (MHC)-linked and non-MHC-linked microsatellite markers, to show that both genetic and non-genetic factors can influence mating success. Male age was reconfirmed to be a contributing factor to the likelihood of a koala pair copulating. This trend could also be related to a pair’s age difference, which was highly correlated with male age in our dataset. Familiarity was reconfirmed to increase the probability of a successful copulation. Our data provided evidence that females select mates based on MHC and genome-wide similarity. Male heterozygosity at MHC class II loci was associated with both pre- and post-copulatory female choice. Genome-wide similarity, and similarity at the MHC class II DAB locus, were also associated with female choice at the post-copulatory level. Finally, certain MHC-linked alleles were associated with either increased or decreased mating success. We predict that utilizing a variety of behavioral and MHC-dependent mate choice mechanisms improves female fitness through increased reproductive success. This study highlights the complexity of mate choice mechanisms in a species, and the importance of ascertaining mate choice mechanisms to improve the success of captive breeding programs.


2009 ◽  
Vol 21 (1) ◽  
pp. 181 ◽  
Author(s):  
T. L. Roth ◽  
D. C. Szymanski ◽  
E. D. Keyster

The global amphibian extinction crisis has stimulated interest in captive breeding programs for this diverse taxa. The goals of this study were to test the effects of exogenous hormone injections (LHRH and hCG) and hibernation on breeding behavior and gamete release by the boreal toad, a temperate species. The 5-year study was initiated with 77 toadlets. Each year, a subset of female and/or male toads was hibernated for 5 months at 4°C. The remaining toads were maintained in a lab receiving 12 h of light daily and ample food and water. Within 48 h of removal from hibernation, toads were paired with hibernated or non-hibernated mates. All toads were weighed and pairs were randomly assigned to treatments. Toads were injected IP with 6 μg LHRH, 250 IU hCG, or saline control and observed for amplexus and egg production. Some treatment groups received a second hormone injection if eggs were not produced within 48 h. Eggs were counted and transferred to aquariums for tadpole and toadlet development. During years 1 to 3, sperm production was assessed in male toads by sampling tank water or urine samples after injections. Data were analyzed using unpaired t-tests and chi-square analyses. In year 1, only 19% of pairs overall exhibited amplexus, none of the males produced sperm and none of the females produced eggs. In year 2, only male toads injected with LHRH exhibited amplexus, and it was more prevalent (P < 0.05) in those that were hibernated than non-hibernated (54.0% and 33.3%, respectively). Percentage of pairs in amplexus in years 2 and 3 (56.9% and 100%) was greater (P < 0.05) than in year 1. Only one and two females produced eggs in years 2 and 3, respectively. In contrast, most hibernated (87.5%) and non-hibernated (75%) males produced sperm. In year 4, eight females produced eggs, but two of these died egg-bound. Interestingly, more (P < 0.05) non-hibernated (7/10) than hibernated (1/10) females produced eggs despite no differences (P ≥ 0.05) in proportion of pairs amplexing or time spent in amplexus between groups. Mean (±SD) weight of female toads producing eggs (58.9 ± 11.9 g) was greater (P < 0.05) than that for non-producing females (43.6 ± 7.0 g). Similarly, 4/7 non-hibernated females produced eggs in year 5, and their weights averaged (58.8 ± 8.3 g). All eggs were produced by females injected a single time with LHRH. Number of eggs per female varied (141–3307), and percentage of eggs developing to tadpoles was low (0–36.5%), but tadpoles were capable of developing into adult toads. In conclusion, two-year-old male boreal toads are mature, exhibiting amplexus and releasing sperm in response to LHRH injections. Females appear to mature at four years of age, and eggs are more likely to be produced by heavier females. Therefore, to enhance breeding success, males should be hibernated and injected with LHRH. In contrast, better productivity in females may be achieved by improving their body condition instead of subjecting them to winter hibernation prior to LHRH injection. Supported by: AZA Conservation Endowment Fund and Colorado Division of Wildlife.


2017 ◽  
Vol 65 (6) ◽  
pp. 347 ◽  
Author(s):  
J. Thomas ◽  
K. Handasyde ◽  
M. L. Parrott ◽  
P. Temple-Smith

The platypus nesting burrow, where females lay eggs and rear their young, has not been well studied. We have little knowledge of its structure and the process of construction. This study aimed to investigate nesting behaviour of breeding females and to describe the structure and features of the burrow. We used infrared cameras to record behaviour of captive breeding female platypuses during the nest-building period, over nine years. After the young had become independent, we excavated 11 nesting burrows and mapped their structural features. Nesting behaviour was observed 7–15 days after mating and was an indicator of gravidity. Females invested an average of 8 h 18 min over 3.5 nights, gathering and transporting wet nesting material to their burrows. The nests were composed mostly of native mat-rush leaves. Nesting burrows varied in length from 3.2 to 10.4 m. They contained narrow tunnels, ‘pugs’ of backfilled earth, dead ends, multiple entrances and a chamber at the end that contained the nest. Appropriate nesting sites and nesting materials must be provided to female platypuses for captive breeding programs to succeed.


2013 ◽  
Vol 35 (2) ◽  
pp. 217 ◽  
Author(s):  
Hayley J. Stannard ◽  
Casey R. Borthwick ◽  
Oselyne Ong ◽  
Julie M. Old

This paper reports successful breeding by 4-year-old female red-tailed phascogales (Phascogale calura) and that they can survive until at least 5 years of age in captivity, whilst males can survive until at least 2 years of age in captivity. These findings have implications for captive breeding programs, providing evidence that older females can be successfully bred. In the longer term we hope these findings may aid conservation efforts of this endangered dasyurid.


Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1515
Author(s):  
Marissa L. Parrott ◽  
Leanne V. Wicker ◽  
Amanda Lamont ◽  
Chris Banks ◽  
Michelle Lang ◽  
...  

Modern zoos are increasingly taking a leading role in emergency management and wildlife recovery. In the face of climate change and the predicted increase in frequency and magnitude of catastrophic events, zoos provide specialised expertise to assist wildlife welfare and endangered species recovery. In the 2019–2020 Australian bushfire season, now called Australia’s Black Summer, a state government-directed response was developed, assembling specialised individuals and organisations from government, non-government organisations, research institutions, and others. Here, we detail the role of Zoos Victoria staff in wildlife triage and welfare, threatened species evacuation and recovery, media and communications, and fundraising during and after the fires. We share strategies for future resilience, readiness, and the ability to mobilise quickly in catastrophic events. The development of triage protocols, emergency response kits, emergency enclosures, and expanded and new captive breeding programs is underway, as are programs for care of staff mental health and nature-based community healing for people directly affected by the fires. We hope this account of our response to one of the greatest recent threats to Australia’s biodiversity, and steps to prepare for the future will assist other zoos and wildlife organisations around the world in preparations to help wildlife before, during, and after catastrophic events.


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