scholarly journals Historical population declines prompted significant genomic erosion in the northern and southern white rhinoceros ( Ceratotherium simum )

2021 ◽  
Author(s):  
Fátima Sánchez‐Barreiro ◽  
Shyam Gopalakrishnan ◽  
Jazmín Ramos‐Madrigal ◽  
Michael V. Westbury ◽  
Marc de Manuel ◽  
...  
Keyword(s):  
Population Declines ◽  
Ceratotherium Simum ◽  
White Rhinoceros ◽  
Southern White Rhinoceros

scholarly journals Historical population declines prompted significant genomic erosion in the northern and southern white rhinoceros (Ceratotherium simum)

2020 ◽  
Author(s):  
Fátima Sánchez-Barreiro ◽  
Shyam Gopalakrishnan ◽  
Jazmín Ramos-Madrigal ◽  
Michael V. Westbury ◽  
Marc de Manuel ◽  
...  
Keyword(s):  
Time Windows ◽  
Empirical Support ◽  
Population Substructure ◽  
Anthropogenic Pressure ◽  
Population Declines ◽  
Effective Population ◽  
Ceratotherium Simum ◽  
Population Extinction ◽  
White Rhinoceros ◽  
Southern White Rhinoceros

AbstractLarge vertebrates are extremely sensitive to anthropogenic pressure, and their populations are declining fast. The white rhinoceros (Ceratotherium simum) is a paradigmatic case: this African megaherbivore suffered a remarkable population reduction in the last 150 years due to human activities. The two white rhinoceros subspecies, the northern (NWR) and the southern white rhinoceros (SWR), however, underwent opposite fates: the NWR vanished quickly after the onset of the decline, while the SWR recovered after a severe bottleneck. Such demographic events are predicted to have an erosive effect at the genomic level, in connection with the extirpation of diversity, and increased genetic drift and inbreeding. However there is currently little empirical data available that allows us to directly reconstruct the subtleties of such processes in light of distinct demographic histories. Therefore to assess these effects, we generated a whole-genome, temporal dataset consisting of 52 re-sequenced white rhinoceros genomes, that represents both subspecies at two time windows: before and during/after the bottleneck. Our data not only reveals previously unknown population substructure within both subspecies, but allowed us to quantify the genomic erosion undergone by both, with post-bottleneck white rhinoceroses harbouring significantly fewer heterozygous sites, and showing higher inbreeding coefficients than pre-bottleneck individuals. Moreover, the effective population size suffered a decrease of two and three orders of magnitude in the NWR and SWR respectively, due to the recent bottleneck. Our data therefore provides much needed empirical support for theoretical predictions about the genomic consequences of shrinking populations, information that is relevant for understanding the process of population extinction. Furthermore, our findings have the potential to inform management approaches for the conservation of the remaining white rhinoceroses.

scholarly journals Historical Population Declines Prompted Significant Genomic Erosion​ in the Northern and Southern White Rhinoceros (​ Ceratotherium simum)

2020 ◽  
Author(s):  
Fátima Sánchez Barreiro ◽  
Shyam Gopalakrishnan ◽  
Jazmín Ramos-Madrigal​ ◽  
Michael Vincent Westbury ◽  
Marc de Manuel​ ◽  
...  
Keyword(s):  
Population Declines ◽  
Ceratotherium Simum ◽  
White Rhinoceros ◽  
Southern White Rhinoceros

scholarly journals Serum protein electrophoresis in healthy and injured southern white rhinoceros (Ceratotherium simum simum)

PLoS ONE ◽  
2018 ◽  
Vol 13 (7) ◽  
pp. e0200347 ◽  
Author(s):  
Emma H. Hooijberg ◽  
Michele Miller ◽  
Carolyn Cray ◽  
Peter Buss ◽  
Gerhard Steenkamp ◽  
...  
Keyword(s):  
Serum Protein ◽  
Protein Electrophoresis ◽  
Serum Protein Electrophoresis ◽  
Ceratotherium Simum ◽  
White Rhinoceros ◽  
Southern White Rhinoceros ◽  
Ceratotherium Simum Simum

scholarly journals Activation of Southern White Rhinoceros (Ceratotherium simum simum) Estrogen Receptors by Phytoestrogens: Potential Role in the Reproductive Failure of Captive-Born Females?

Endocrinology ◽  
2012 ◽  
Vol 153 (3) ◽  
pp. 1444-1452 ◽  
Author(s):  
Christopher Tubbs ◽  
Phillip Hartig ◽  
Mary Cardon ◽  
Nicole Varga ◽  
Matthew Milnes
Keyword(s):  
Estrogen Receptors ◽  
Potential Role ◽  
Physiological Role ◽  
Reproductive Failure ◽  
Vertebrate Species ◽  
Ceratotherium Simum ◽  
White Rhinoceros ◽  
Southern White Rhinoceros ◽  
Ceratotherium Simum Simum

The captive southern white rhinoceros (SWR; Ceratotherium simum simum) population serves as an important genetic reservoir critical to the conservation of this vulnerable species. Unfortunately, captive populations are declining due to the poor reproductive success of captive-born females. Captive female SWR exhibit reproductive problems suggested to result from continual ovarian follicular activity and prolonged exposure to endogenous estrogen. However, we investigated the potential role of exogenous dietary phytoestrogens in the reproductive failure of SWR by cloning and characterizing in vitro phytoestrogen binding and activation of recombinant SWR estrogen receptors (ESR). We compared those characteristics with recombinant greater one-horned rhinoceros (GOHR; Rhinoceros unicornis) ESR, a species that receives similar captive diets yet reproduces relatively well. Our results indicate that phytoestrogens bind rhino ESR in a manner similar to other vertebrate species, but there are no differences found in phytoestrogen binding affinity of SWR ESR compared with GOHR ESR. However, species-specific differences in ESR activation by phytoestrogens were detected. The phytoestrogen coumestrol stimulated greater maximal activation of SWR ESR1 than GOHR ESR1. SWR ESR2 were also more sensitive to phytoestrogens and were activated to a greater extent by both coumestrol and daidzein. The concentrations in which significant differences in ESR activation occurred (10−7 to 10−5m) are consistent with circulating concentrations measured in other vertebrate species. Taken together, these findings suggest that phytoestrogens potentially pose a risk to the reproductive health of captive SWR. However, additional studies are needed to further clarify the physiological role of dietary phytoestrogens in the reduced fertility of this species.

scholarly journals Development and evaluation of indirect enzyme-linked immunosorbent assays for the determination of immune response to multiple clostridial antigens in vaccinated captive bred southern white rhinoceros (Ceratotherium simum simum)

2020 ◽  
Vol 62 (1) ◽  
Author(s):  
Angela Buys ◽  
Jannie Crafford ◽  
Henriette van Heerden
Keyword(s):  
Type A ◽  
Analytical Sensitivity ◽  
Alpha Toxin ◽  
Ceratotherium Simum ◽  
International Reference ◽  
White Rhinoceros ◽  
Antibody Titres ◽  
Southern White Rhinoceros ◽  
Immunosorbent Assays ◽  
Ceratotherium Simum Simum

Abstract Background An overall increase in poaching of white rhinoceros results in captive breeding becoming a significant component of white rhinoceros conservation. However, this type of conservation comes with its own difficulties. When wildlife is captured, transported and/or confined to a boma environment, they are more predisposed to diseases caused by bacterial organisms such as spore forming Clostridium spp. A southern white rhinoceros (Ceratotherium simum simum) population on a captive bred farm was suspected to be affected by Clostridium infections. These endangered animals were apparently exposed to Clostridium spp., in the conservation area previously used for cattle farming. The rhinoceros population on the breeding operation property was vaccinated with a multi-component clostridial vaccine registered for use in cattle. Multiple indirect enzyme-linked immunosorbent assays (iELISAs) were developed in order to evaluate the serum antibody titres of these vaccinated animals. In evaluating vaccine efficacy, the gold standard mouse neutralization test (MNT) was not available and therefore iELISAs were developed for the detection of serum antibodies to C. perfringens type A (alpha toxin), C. chauvoei (whole cell), C. novyi (alpha toxin), C. septicum (alpha toxin) and C. sordellii (lethal toxin) in the white rhinoceros population using international reference sera of equine origin. Antibody titres against each clostridial antigen was evaluated in the vaccinated white rhinoceros population (n = 75). Analytical specificity showed slight cross-reactions for C. chauvoei and C. perfringens type A with the other antigens. Individual assay cut-off values were calculated with 95% confidence. Coefficient of variance (CV) values for both the international reference sera and in-house control sera across all the antigens were well below 16%, indicating good assay repeatability. This convenient and fast assay is suitable for monitoring humoral immune responses to clostridial antigens in vaccinated white rhinoceroses. Results Checkerboard titrations indicated optimal antigen and antibody concentrations to be used for each respective iELISA developed. Each titration set of the respective international reference and in-house control sera showed good repeatability with low standard deviations and coefficient of variance values calculated between repeats for each antigen. Individual assays proved repeatable and showed good analytical sensitivity and specificity. Conclusions The developed iELISAs are able to evaluate antibody profiles of phospholipase C, C. chauvoei whole cells, TcnA, ATX, TcsL in white rhinoceros serum using international reference sera.

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