Mitochondrial DNA and microsatellite DNA variation in domestic reindeer (Rangifer tarandus tarandus) and relationships with wild caribou (Rangifer tarandus granti, Rangifer tarandus groenlandicus, and Rangifer tarandus caribou)

Reindeer (Rangifer tarandus tarandus) in Alaska are semidomestic livestock descended from 1280 animals introduced from Siberia, Russia, approximately 100 years ago. Genetic variation at 18 microsatellite DNA loci and the cytochrome b gene of mitochondrial DNA (mtDNA) was quantified in reindeer from Alaska, Siberia (Russia), and Scandinavia and compared with wild North American caribou. Mean sequence divergence among 15 mtDNA haplotypes in reindeer was 0.007 substitutions per nucleotide site, and reindeer mtDNA is polyphyletic with caribou mtDNA. Microsatellite allele and mtDNA haplotype frequencies are similar between Alaskan and Russian reindeer and differentiated between these and Scandinavian reindeer. The frequencies of microsatellite alleles and mtDNA haplotypes are different in reindeer and wild caribou (Rangifer tarandus granti, Rangifer tarandus groenlandicus, and Rangifer tarandus caribou). Alaskan reindeer have maintained a genetic variation comparable to that in Russia and differentiated from that of wild caribou, >100 years after their introduction to Alaska.     

An epizootic of besnoitiosis in captive caribou (Rangifer tarandus caribou), reindeer (Rangifer tarandus tarandus) and mule deer (Odocoileus hemionus hemionus)

Besnoitia sp. was diagnosed in two caribou (Rangifer tarandus caribou) which died of pneumonia at the Assiniboine Park Zoo (Winnipeg, Manitoba, Canada) in 1983. During the following 3 yr besnoitiosis spread to an isolated herd of caribou, to mule deer (Odocoileus hemionus hemionus) and to reindeer (Rangifer tarandus tarandus). Reduction of exposure to biting insects appears to have reduced the transmission of besnoitiosis within the reindeer herd. The morbidity rate was approximately 82% in caribou and 67% in mule deer over the age of 2 mo. Most animals with clinical signs were euthanized; this precluded an estimation of the disease-related mortality rate. Twenty-eight caribou, 10 mule deer and three reindeer have been euthanized or died as a result of this epidemic. Attempts to artificially transmit the disease to potentially susceptible intermediate and definitive hosts were unsuccessful.     

An investigation of arterial disease in Alaskan reindeer and Caribou.

No significant lesions of atherosclerosis or other vascular diseases were found in the aorta and coronary arteries of 34 reindeer and 15 caribou (Rangifer tarandus). Serum lipid, phospholipid, cholesterol and triglyceride levels were similar in caribou and reindeer and did not differ greatly from those reported in other ruminants.     

Evidence of alphaherpesvirus infections in Alaskan caribou and reindeer

Background  

The reindeer (Rangifer tarandus tarandus) industry in Alaska began with animals imported from Siberia (Russia) in the 1890's. Cervid herpes virus 2 (CvHV2) is endemic in reindeer in Scandinavia. We sought to determine if the same virus, or similar herpesviruses, were circulating in Alaskan reindeer and caribou (Rangifer tarandus granti). Serum samples from 292 reindeer were collected during annual reindeer handlings (1988-2005) near Nome, Alaska. In 2005, swab samples were collected from 40 calves from this herd, near Nome, Alaska. In 2007, ocular and nasal swab samples were collected from 30 apparently healthy reindeer calves near Wales, Alaska. Samples of plasma and white blood cells were collected from three Alaskan caribou herds, Mulchatna (n = 24), Teshekpuk (n = 34) and the Western Arctic (n = 87) in 2009.     

Allocating protein to reproduction in arctic reindeer and caribou

Reindeer (Rangifer tarandus tarandus) and caribou (Rangifer tarandus granti) use body stores (capital) and food intake (income) for survival and reproduction. Intakes of low-nitrogen (N) food declined in winter and increased in spring (51-83 g dry matter kg(-0.75) d(-1)). Reindeer calved before regaining food intake, whereas caribou calved 28 d later. Body N was conserved by minimizing oxidation of amino acid N to urea. Maternal protein stored from early winter was used for 96% of fetal growth in reindeer but only 84% of fetal growth in later-birthing caribou. Both subspecies rely on maternal body protein for 91% of the protein deposited in the neonate via milk over the first 4 wk. All females lost body protein over winter, but lactating females continued to lose protein while nonreproductive females regained protein. Net costs of lactation above maintenance were greater for N (110%-130%) than for energy (40%-59%). Large fat stores in reindeer spare body protein from oxidation in winter, whereas in caribou, less fat with the same body protein favors migration when food is inadequate. The resilience of Rangifer populations to variable patterns of food supply and metabolic demand may be related to their ability to alter the timing and allocation of body protein to reproduction.     

Genetic variation in domestic reindeer and wild caribou in Alaska

Reindeer ( Rangifer tarandus tarandus ) were introduced into Alaska 100 years ago and have been maintained as semidomestic livestock. They have had contact with wild caribou ( R. t. granti ) herds, including deliberate crossbreeding and mixing in the wild. Reindeer have considerable potential as a domestic animal for meat or velvet antler production, and wild caribou are important to subsistence and sport hunters. Our objective was to quantify the genetic relationships of reindeer and caribou in Alaska. We identified allelic variation among five herds of wild caribou and three herds of reindeer with DNA sequencing and restriction enzymes for three loci: a DQA locus of the major histocompatibility complex ( Rata-DQA1 ), K-casein and the D-loop of mitochondrial DNA. These loci are of interest because of their potential influence on domestic animal performance and the fitness of wild populations. There is considerable genetic variation in reindeer and caribou for all three loci, including five, three and six alleles for DQA , K-casein and D-loop respectively. Most alleles occur in both reindeer and caribou, which may be the result of recent common ancestry or genetic introgression in either direction. However, allele frequencies differ considerably between reindeer and caribou, which suggests that gene flow has been limited.     

Genetic variation in caribou and reindeer (Rangifer tarandus)

Genetic variation at seven microsatellite DNA loci was quantified in 19 herds of wild caribou and domestic reindeer (Rangifer tarandus) from North America, Scandinavia and Russia. There is an average of 2.0-6.6 alleles per locus and observed individual heterozygosity of 0.33-0.50 in most herds. A herd on Svalbard Island, Scandinavia, is an exception, with relatively few alleles and low heterozygosity. The Central Arctic, Western Arctic and Porcupine River caribou herds in Alaska have similar allele frequencies and comprise one breeding population. Domestic reindeer in Alaska originated from transplants from Siberia, Russia, more than 100 years ago. Reindeer in Alaska and Siberia have different allele frequencies at several loci, but a relatively low level of genetic differentiation. Wild caribou and domestic reindeer in Alaska have significantly different allele frequencies at the seven loci, indicating that gene flow between reindeer and caribou in Alaska has been limited.     

Foetal Stages of Antler Development

Foetuses of reindeer, Rangifer tarandus tarandus L., were collected at slaughter and studied for structural primordial stages of pedicle formation and antler growth. Fresh foetuses studied in January and February exhibited a round, pale area with an epidermal infolding or groove at the site of the future antler development. Also, in an ethanol-fixed caribou foetus from Alaska, an epidermal invagination could be seen in the area of later pedicle formation. No protruding bone or cartilage was observed as primordial stages of antler growth in reindeer foetuses collected from 10 November to 26 April. It is concluded that an epidermal infolding exists in the foetus of telemetacarpal cervids such as reindeer and caribou.     

Behavioural trade-offs in response to external stimuli: time allocation of an Arctic ungulate during varying intensities of harassment by parasitic flies

1. Macroparasites may be a major factor shaping animal behaviour. Tundra ecosystems inhabited by caribou and reindeer (Rangifer tarandus) are known for large concentrations of ectoparasites including mosquitoes (Culicidae) and black flies (Simuliidae), as well as endoparasitic oestrid flies (Oestridae). 2. Increased intensity and duration of insect harassment because of climatic warming is hypothesized as a potential factor in recent declines of Rangifer across the circumpolar north. Although there is a well-observed relationship between insect harassment and caribou/reindeer behaviour, the influence of ecto- relative to endoparasitic species is unclear. Climatic changes may favour the activity patterns, distribution or abundance of certain insect species; thus, understanding differential effects on the behaviour of Rangifer is important. 3. We recorded caribou behaviour using group scan and focal sampling methods, while simultaneously trapping insects and recording weather conditions on the postcalving/summer range of the Bathurst barren-ground caribou herd in Northwest Territories and Nunavut, Canada, during 2007-2009. 4. We developed statistical model sets representing hypotheses about the effects of insects, weather, habitat/location, and date/time on caribou behaviour. We used multinomial logistic regression models to explore factors affecting the relative dominance of behaviour types within groups of caribou and fractional multinomial logistic regression models to determine factors influencing time allocation by individual caribou. We examined changes in feeding intensity using fractional logistic regression. 5. Relative dominance of insect avoidance behaviour within caribou groups and time allocation to insect avoidance by individual caribou increased when oestrid flies were present or black flies were active at moderate-high levels. Mosquito activity had relatively little effect on caribou behaviour. Time spent feeding was reduced by the greatest degree when all three insect types were present in combination. Feeding intensity was influenced to a greater extent by the accumulation of growing degree days over the course of the postcalving/summer season than by insect activity. Changes in Arctic systems that increase the activity/abundance of ecto- and endoparasites could have implications for the productivity of Rangifer populations.     

Why don't Svalbard reindeer migrate?

Reindeer and caribou are best known as migratory, seasonally nomadic animals; many continental populations, for example, travel between distinct summer and winter ranges which may lie hundreds of km apart. Much less is known about the movements of animals belonging to island populations. This paper describes seasonal and annual movements of wild reindeer Rangifer tarandus platyrhynchus on the high arctic archipelago of Svalbard, based on observations of nine animals captured and individually marked in Adventdalen, Spitsbergen, between 1977 and 1982. Four ear-tagged reindeer (one male and three females) were followed extensively for between four and seven years. Five radio-collared females were followed intensively for seven months in 1982. Svalbard reindeer seem neither to undertake long migrations nor to be nomadic within seasons like mountain reindeer or barren-ground caribou. They appear instead to use small, traditional, seasonal home ranges more, for example, like red deer or wild sheep. This atypical behaviour is discussed in relation to the dispersion of reindeers' resources in Svalbard.     

Molecular identification of Taenia spp. in wolves (Canis lupus), brown bears (Ursus arctos) and cervids from North Europe and Alaska

Taenia tapeworms of Finnish and Swedish wolves (Canis lupus) and Finnish brown bears (Ursus arctos), and muscle cysticerci of Svalbard reindeer (Rangifer tarandus platyrhynchus), Alaskan Grant's caribou (Rangifer tarandus granti) and Alaskan moose (Alces americanus) were identified on the basis of the nucleotide sequence of a 396 bp region of the mitochondrial cytochrome c oxidase subunit 1 gene. Two species were found from wolves: Taenia hydatigena and Taenia krabbei. The cysticerci of reindeer, caribou and one moose also represented T. krabbei. Most of the cysticercal specimens from Alaskan moose, however, belonged to an unknown T. krabbei-like species, which had been reported previously from Eurasian elks (Alces alces) from Finland. Strobilate stages from two bears belonged to this species as well. The present results suggest that this novel Taenia sp. has a Holarctic distribution and uses Alces spp. as intermediate and ursids as final hosts.     

Sexual dimorphism in the pelvic bones of Svalbard reindeer, Rangifer tarandus platyrhynchus

The determination of sex of carcasses of reindeer and caribou (Rangifer tarandus) is complicated because both sexes normally carry antlers. Growth curves of males and females diverge sufficiently so that the length of long bones can often indicate the sex of a carcass if its age at death is known; results, however, are not always conclusive. Pronounced sexual dimorphism was found in the breadth of the ventro-medial border (rim) of the acetabulum of adult Svalbard reindeer. Measurement of the rim of the acetabulum thus provides a quick and conclusive means for determining the sex of carcasses of these animals. Similar results have been found in several other species of ungulates. Reasons for the dimorphism and for the non-normal distribution of the data for both sexes in reindeer are discussed.     

Evaluation of the fluorescence polarization assay and comparison to other serological assays for detection of brucellosis in cervids

The complement fixation test (CFT), competitive enzyme immunoassay (CELISA), indirect enzyme immunoassay (IELISA) and fluorescence polarization assay (FPA) were evaluated for the detection of antibodies to Brucella abortus and Brucella suis biotype 4 in caribou (Rangifer tarandus caribou), elk (Cervus elapus), red deer (Cervus elapus), and reindeer (Rangifer tarandus tarandus). When combining the data the FPA and the CELISA were determined to be the most suitable tests for serodiagnosis of Cervidae. The overall actual sensitivity of the CFT and the IELISA was 100%. The overall actual sensitivity for the CELISA and FPA was 99%. The overall relative specificity of the CFT (including treatment of anti-complementary data as positive or negative for analysis), the CELISA, the IELISA and the FPA were 65%, 93%, 99%, 99%, and 99%, respectively. The specificities of the buffered plate agglutination test (BPAT), the CFT, the CELISA, the FPA and the IELISA for 55 elk vaccinated with B. abortus strain 19 and tested 4 mo post vaccination were 14%, 31%, 51%, 84%, and 2%, respectively. The FPA is the diagnostic test of choice because it has sensitivity and specificity values comparable to the CELISA; it has the capability to distinguish vaccinal antibody and antibody resulting from exposure to cross-reacting organisms such as Yersinia enterocolitica 0:9 from antibody to Brucella spp. in most cases; it is technically simple to do; it is adaptable to field use and it is relatively inexpensive.     

Survival in the Rockies of an endangered hybrid swarm from diverged caribou (Rangifer tarandus) lineages

In North America, caribou ( Rangifer tarandus ) experienced diversification in separate refugia before the last glacial maximum. Geographical isolation produced the barren-ground caribou ( Rangifer tarandus groenlandicus ) with its distinctive migratory habits, and the woodland caribou ( Rangifer tarandus caribou ), which has sedentary behaviour and is now in danger of extinction. Herein we report on the phylogenetics, population structure, and migratory habits of caribou in the Canadian Rockies, utilizing molecular and spatial data for 223 individuals. Mitochondrial DNA analyses show the occurrence of two highly diverged lineages; the Beringian–Eurasian and North American lineages, while microsatellite data reveal that present-day Rockies' caribou populations have resulted from interbreeding between these diverged lineages. An ice-free corridor at the end of the last glaciation likely allowed, for the first time, for barren-ground caribou to migrate from the North and overlap with woodland caribou expanding from the South. The lack of correlation between nuclear and mitochondrial data may indicate that different environmental forces, which might also include human-caused habitat loss and fragmentation, are currently reshaping the population structure of this postglacial hybrid swarm. Furthermore, spatial ecological data show evidence of pronounced migratory behaviour within the study area, and suggest that the probability of being migratory may be higher in individual caribou carrying a Beringian–Eurasian haplotype which is mainly associated with the barren-ground subspecies. Overall, our analyses reveal an intriguing example of postglacial mixing of diverged lineages. In a landscape that is changing due to climatic and human-mediated factors, an understanding of these dynamics, both past and present, is essential for management and conservation of these populations.     

High genetic connectivity and introgression from domestic reindeer characterize northern Alaska caribou herds

Defining genetic populations and detecting hybridization with introduced or domestic taxa are two major concerns for the conservation of population-level diversity. We studied the genetic population structure of large, migratory caribou herds (Rangifer tarandus granti) on Alaska’s North Slope and their potential hybridization with introduced domestic reindeer (R. t. tarandus). Using a population genetics approach, we determined: (1) whether the four caribou herds could be differentiated; (2) how distance and population size appear to drive genetic population structure; and (3) how contact with reindeer has affected the genetic identity of herds. Samples from four caribou herds (n = 245) and reindeer (n = 67) were analyzed at 19 microsatellite loci. We found that North Slope caribou are isolated by distance, with no differentiation among herd pairs except for the most geographically distant herds (F _st  = 0.003, Jost’s D = 0.023; P-values < 0.001). We detected reindeer-caribou admixture in all populations except Kodiak Island, including 8 % of individuals in caribou herds and 14 % of individuals in Seward Peninsula reindeer herds. However, considering the stable or increasing trend in North Slope herds, reindeer introgression has had no apparent deleterious effect on herd demographics. Our findings indicate long-term genetic exchange among North Slope caribou herds when their ranges overlap, and suggest that herd size may influence susceptibility to reindeer introgression. As North Slope herd ranges are increasingly altered by industrial development, this study can provide a baseline for detecting potential future impacts to what are currently large, diverse, and naturally evolving herds.     

The primary structure of hemoglobin from reindeer (Rangifer tarandus tarandus) and its functional implications

The primary structures of alpha- and beta-chains of hemoglobin from reindeer (Rangifer tarandus tarandus) were determined. Comparison of the reindeer hemoglobin sequence with those of human and bovine hemoglobins showed 50 and 29 substitutions per alpha beta dimer, respectively. The influence of replacements on the modulation of hemoglobin oxygen affinity by heterothopic ligands and temperature, as well as their importance on the structure-function relationships in hemoglobin are discussed.     

Ceruloplasmin as an indicator of copper reserves in wild ruminants at high latitudes

Northern ungulates must establish trace mineral reserves when forage is available in spring and summer to sustain biochemical activities through the long winter. Copper (Cu), zinc (Zn) and iron (Fe) reserves were measured in the serum, digestive tract, liver, and kidney of six male caribou and reindeer (Rangifer tarandus) fed a complete pelleted ration. Dry matter content and absolute amounts of Cu, Zn and Fe were highest in the liver. Digesta contents of Cu and Zn were greatest in the rumen but dry matter concentrations were greatest in the cecum reflecting the high levels of Cu and Zn in the diet. Serum ceruloplasmin (an oxidase containing Cu) activity was related to liver copper in captive reindeer and caribou (P < 0.05, r2 = 0.82) during spring and winter but not during the rut. Michaelis-Menten kinetics of ceruloplasmin were measured in sera from captive reindeer, muskox (Ovibos moschatus) and moose (Alces alces) (n = 3/species). Maximum velocities (VMAX) were 42, 20 and 9 (IU x L(-1)); kM were 0.38, 0.55 and 0.62 (mM) for muskox, reindeer and moose respectively. Wild caribou (n = 3) from the Teshekpuk herd and moose (n = 3) from the Colville River had lower VMAX (7 IU x L(-1)) and higher km (1.9 mM) than their captive conspecifics. These kinetic parameters probably reflect differences in ceruloplasmin structure between species as well as differences in tissue reserves between populations within each species. Serum ceruloplasmin activity and kinetics can provide a non-lethal alternative to direct measures of hepatic Cu reserves in wild and captive populations. However, the method requires validation for the effects of sex, season, development and disease in each species.     

Serum biochemistry, serology, and parasitology of boreal caribou (Rangifer tarandus caribou) in the Northwest Territories, Canada

Boreal caribou (Rangifer tarandus caribou) are an ecologically and culturally important wildlife species and now range almost exclusively in the boreal forests of Canada, including the Northwest Territories, northern Alberta, and British Columbia. Boreal caribou are threatened throughout their Canadian range because of direct and indirect natural and anthropogenic factors. In the Northwest Territories, however, they have a continuous range that overall has not yet been subjected to the same degree of anthropogenic habitat fragmentation and degradation that has occurred elsewhere in Canada. To monitor the health of boreal caribou populations and individuals, we collected blood from 104 adult, female boreal caribou captured between March 2003 and February 2006 and measured serum biochemical parameters. Serum creatinine was higher in pregnant than in nonpregnant caribou. Several biochemical parameters differed among years, but they tended to be similar to those reported for reindeer. Serum antibodies were found to an alphaherpesvirus, Toxoplasma gondii, and to the Mycobacterium avium subspecies paratuberculosis in 37.5, 2.9, and 1.3% of boreal caribou, respectively. Fecal samples were collected from 149 boreal caribou, and Cryptosporidium sp. oocysts, Giardia sp. cysts, trichostrongyle ova, dorsal-spined nematode larvae, cestode ova, and Eimeria sp. were found. Trypanosoma sp. was detected in the blood of 72.1% of boreal caribou. Eimeria sp., Cryptosporidium sp., and Giardia sp. have not been previously reported in boreal caribou.     

Septicemic listeriosis in a reindeer calf

Septicemic listeriosis is described in a 2-day-old reindeer calf (Rangifer tarandus tarandus) from a local zoo. The gross and microscopic lesions were typical of disease caused by bacterial septicemia. Major lesions included necrosis of the liver, lung, adrenal gland, spleen, and lymph node. The diagnosis was suspected by special histopathological stains and confirmed by isolation of Listeria monocytogenes from multiple organs. This is the first report of listeriosis in a reindeer.     

DNA evidence that Ostertagia gruehneri and Ostertagia arctica (Nematoda: ostertagiinae) in reindeer from Norway and Svalbard are conspecific

DNA sequences of ITS-1 and ITS-2 of rDNA were determined for 16 individual adult males each of Ostertagia gruehneri and Ostertagia arctica from Svalbard reindeer (Rangifer tarandus platyrhynchus) and Eurasian tundra reindeer (R. t. tarandus). Each ITS was virtually identical in O. gruehneri and O. arctica and the three mixed bases detected were shared by both species. Our results strongly suggest that O. gruehneri and O. arctica are dimorphic males of the same species.