scholarly journals Semen parameters and electron microscope observations of spermatozoa of the red wolf, Canis rufus

Reproduction ◽  
1998 ◽  
Vol 114 (1) ◽  
pp. 95-101 ◽  
Author(s):  
J. K. Koehler ◽  
C. C. Platz ◽  
W. Waddell ◽  
M. H. Jones ◽  
S. Behrns
2000 ◽  
Vol 78 (12) ◽  
pp. 2156-2166 ◽  
Author(s):  
Paul J Wilson ◽  
Sonya Grewal ◽  
Ian D Lawford ◽  
Jennifer NM Heal ◽  
Angela G Granacki ◽  
...  

The origin and taxonomy of the red wolf (Canis rufus) have been the subject of considerable debate and it has been suggested that this taxon was recently formed as a result of hybridization between the coyote and gray wolf. Like the red wolf, the eastern Canadian wolf has been characterized as a small "deer-eating" wolf that hybridizes with coyotes (Canis latrans). While studying the population of eastern Canadian wolves in Algonquin Provincial Park we recognized similarities to the red wolf, based on DNA profiles at 8 microsatellite loci. We examined whether this relationship was due to similar levels of introgressed coyote genetic material by comparing the microsatellite alleles with those of other North American populations of wolves and coyotes. These analyses indicated that it was not coyote genetic material which led to the close genetic affinity between red wolves and eastern Canadian wolves. We then examined the control region of the mitochondrial DNA (mtDNA) and confirmed the presence of coyote sequences in both. However, we also found sequences in both that diverged by 150 000 - 300 000 years from sequences found in coyotes. None of the red wolves or eastern Canadian wolf samples from the 1960s contained gray wolf (Canis lupus) mtDNA sequences. The data are not consistent with the hypothesis that the eastern Canadian wolf is a subspecies of gray wolf as it is presently designated. We suggest that both the red wolf and the eastern Canadian wolf evolved in North America sharing a common lineage with the coyote until 150 000 - 300 000 years ago. We propose that it retain its original species designation, Canis lycaon.


2018 ◽  
Vol 99 (5) ◽  
pp. 1033-1041
Author(s):  
Eric M Gese ◽  
William T Waddell ◽  
Patricia A Terletzky ◽  
Chris F Lucash ◽  
Scott R McLellan ◽  
...  

Abstract Cross-fostering offspring with nonbiological parents could prove useful to augment populations of endangered carnivores. We used cross-fostering to augment captive-born and wild-born litters for the endangered red wolf (Canis rufus). Between 1987 and 2016, 23 cross-fostering events occurred involving captive-born pups fostered into captive litters (n = 8 events) and captive-born pups fostered into wild recipient litters (n = 15 events). Percentage of pups surviving 3 and 12 months was 91.7% for captive-born pups fostered into captive recipient litters. For pups fostered into wild litters, percentage of pups surviving 5 months was > 94% among fostered pups (pups fostered into a wild red wolf litter or replaced a hybrid litter), pups in recipient litters (wild-born litters receiving fostered pups), and pups in control litters (wild-born litters not in a fostering event) when using pups with known fates. Including pups with unknown fates as deaths, percentage of pups surviving 5 months was > 54% among fostered pups, pups in recipient litters, and pups in control litters. Among wild litters, percentage of pups surviving 12 months was > 82% among fostered pups, pups in recipient litters, and pups in control litters when using pups with known fates. Including pups with unknown fates as deaths, percentage of pups surviving 12 months was > 48% among fostered pups, pups in recipient litters, and pups in control litters. Although survival to 12 months was similar among the groups, average life span was different with pups in control litters living 3.3 years, pups in recipient litters living 4.6 years, and fostered pups living 5.6 years. Of fostered pups surviving > 12 months in the wild, 9 animals whelped or sired 26 litters. Cross-fostering was successful at augmenting litter size for red wolves without any deleterious effects on recipient litters, illustrating fostering as a tool for increasing populations of endangered carnivores.


2015 ◽  
Vol 46 (3) ◽  
pp. 617-620 ◽  
Author(s):  
Jennifer L. Hurley-Sanders ◽  
Kurt K. Sladky ◽  
Elizabeth C. Nolan ◽  
Michael R. Loomis

2017 ◽  
Vol 4 (7) ◽  
pp. 170052 ◽  
Author(s):  
Christopher Wolf ◽  
William J. Ripple

The majority of the world's terrestrial large carnivores have undergone substantial range contractions and many of these species are currently threatened with extinction. However, there has been little effort to fully quantify the extent of large carnivore range contractions, which hinders our ability to understand the roles and relative drivers of such trends. Here we present and analyse a newly constructed and comprehensive set of large carnivore range contraction maps. We reveal the extent to which ranges have contracted since historical times and identify regions and biomes where range contractions have been particularly large. In summary, large carnivores that have experienced the greatest range contractions include the red wolf ( Canis rufus ) (greater than 99%), Ethiopian wolf ( Canis simensis ) (99%), tiger ( Panthera tigris ) (95%) and lion ( Panthera leo ) (94%). In general, the greatest range contractions occurred in Southeastern Asia and Africa. Motivated by the ecological importance of intact large carnivore guilds, we also examined the spatial extent of intact large carnivore guilds both for the entire world and regionally. We found that intact carnivore guilds occupy just 34% of the world's land area. This compares to 96% in historic times. Spatial modelling of range contractions showed that contractions were significantly more likely in regions with high rural human population density, cattle density or cropland. Our results offer new insights into how best to prevent further range contractions for the world's largest carnivores, which will assist efforts to conserve these species and their important ecological effects.


Author(s):  
Tyler K. Chafin ◽  
Marlis R. Douglas ◽  
Michael E. Douglas

AbstractHybridization is well recognized as a driver of speciation, yet it often remains difficult to parse phylogenomically in that post-speciation gene flow frequently supersedes an ancestral signal. Here we examined how interactions between recombination and gene flow shaped the phylogenomic landscape of red wolf to create non-random retention of introgressed ancestry. Our re-analyses of genomic data recapitulate fossil evidence by demonstrating red wolf was indeed extant and isolated prior to more recent admixture with other North American canids. Its more ancient divergence, now sequestered within low-recombinant regions on the X-chromosome (i.e., chromosomal ‘refugia’), is effectively masked by multiple, successive waves of secondary introgression that now dominate its autosomal ancestry. These interpretations are congruent with more theoretical explanations that describe the manner by which introgression can be localized within the genome through recombination and selection. They also tacitly support the large-X effect, i.e., the manner by which loci that contribute to reproductive isolation can be enriched on the X-chromosome. By contrast, similar, high recombinant regions were also found as enriched within very shallow gene trees, thus reflecting post-speciation gene flow and a compression of divergence estimates to 1/20th of that found in recombination ‘cold spots’. Our results effectively reconcile conflicting hypotheses regarding the impact of hybridization on evolution of North American canids and support an emerging framework within which the analysis of a phylogenomic landscape structured by recombination can be used to successfully address the macroevolutionary implications of hybridization.


2020 ◽  
Vol 32 (2) ◽  
pp. 242
Author(s):  
S. Kamen ◽  
J. Nagashima ◽  
N. Songsasen ◽  
M. Ferraz

Development of assisted reproductive technologies for the critically endangered red wolf (Canis rufus) is crucial to the maintenance of genetic diversity to support species recovery. Towards this goal, a cryopreservation protocol has previously been developed for red wolf sperm; however, the ability of the gametes to undergo capacitation has not been assessed in this species. Previously, we have shown that oviductal extracellular vesicles (oEVs) improve cat sperm motility and fertilizing ability. The objectives were to (1) compare the effects of culture media on motility and acrosomal integrity of fresh sperm, and select the best medium that can be used in a capacitation protocol; (2) identify potential biomarkers for sperm cryo-tolerance; and (3) determine the influence of canine oEVs on sperm survival and motility post-thaw. In Study 1, sperm were collected by electro-ejaculation from adult red wolves (n=8) and immediately cryopreserved in TRIS-egg yolk buffer with 8% glycerol or incubated for 18h in 5% CO2 and 38.5°C in one of the following media: canine capacitation medium (CCM), FERT-TALP (FERT), NCSU, synthetic oviductal fluid (SOF) and TRIS. At 0, 1, 2, 3, 4, and 18h, sperm were evaluated for total motility and acrosome integrity (FITC-PNA). In Study 2, sperm with high (>80%, HM, n=2 wolves) and low (<15%, LM, n=2 wolves) motility post-incubation at 4°C in the cryopreservation medium for 18h were subjected to proteomic analysis. In Study 3, oviducts were collected from domestic dogs (1-9 years, n=12) after elective spaying, and oEVs from various stages of the oestrous cycle [early follicular (EF), late follicular (LF), early luteal (EL), and late luteal (LL)] were isolated using the Total Exosome Isolation kit (Invitrogen). Frozen-thawed red wolf sperm (n=4 males) were incubated with 30×106 oEVs in non-capacitating CCM, and assessed as in study 1 at 0, 0.5, 1, 2, 3, 4, 6, 8, and 10h. Data were analysed using a paired samples t-test with 95% CI (Prism8, GraphPad Inc.). Sperm incubated in CCM and NCSU had higher motility than those in FERT, SOF, and TRIS after 2h of incubation and onward (2 h: 65±6, 68±6, 42±10, 57±8, and 43±5; 3 h: 60±9, 63±8, 36±11, 46±9, and 34±6; 4 h: 60±9, 60±10, 30±10, 43±8, and 20±5; 18 h: 12±7, 15±7, 9±5, 3±2, and 0, respectively; P<0.05). After 1h of incubation, samples incubated in CCM, NCSU, and SOF had a higher number of sperm with intact acrosomal membranes (P>0.05) than other treatments. A total of 179 proteins were identified, of which 129, including those regulating energy metabolism and mitochondrial mediated apoptosis, were differentially expressed between HM and LM. Preliminary data from Study 3 suggested that thawing and incubating sperm in the presence of LF, EL, and LL oEVs improved sperm motility. In conclusion, CCM and NCSU sustained sperm survival after invitro incubation and could be candidates for invitro fertilization studies in the red wolf. Data generated from sperm proteomic analysis provided insights into cellular pathways regulating sperm cryo-sensitivity. Finally, we demonstrated the potential of oEVs in improving wolf sperm survival post-thawing.


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