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.     

Preliminary studies on the etiology of keratoconjunctivitis in reindeer (Rangifer tarandus tarandus) calves in Alaska

Keratoconjunctivitis outbreaks occur each summer in reindeer (Rangifer tarandus tarandus) herds in western Alaska, USA. This condition has not been well characterized nor has a definitive primary etiologic agent been identified. We evaluated the eyes of 660 calves near Nome, Alaska, between 29 June and 14 July 2005. Clinical signs of keratoconjunctivitis were observed in 26/660 calves (3.9%). Samples were collected from the conjunctival sac of both affected (n=22) and unaffected (n=24) animals for bacterial culture, enzyme-linked immunosorbent assay testing for Chlamydophila psittaci, and for polymerase chain reaction assays for Mycoplasma and Moraxella spp. No primary bacterial or viral etiologic agent(s) were isolated or identified. The cause of keratoconjunctivitis among reindeer calves was not determined, but it could involve an anaerobic bacteria, a difficult-to-isolate viral agent, stress associated with repeated handling, ocular foreign bodies, exposure to corral dust or arthropods, or a combination.     

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.     

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.     

Dermacentor albipictus (Acari, Ixodidae) on captive reindeer and free-ranging woodland caribou

Infestations of winter ticks (Dermacentor albipictus) on two captive reindeer (Rangifer tarandus tarandus) are reported and may be associated with increased grooming and alopecia. Over 400,000 ticks were recovered from one reindeer. Few ticks (less than 25 ticks/animal) were found on three free-ranging woodland caribou (Rangifer tarandus caribou).     

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.     

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.     

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.     

Population structure over a broad spatial scale driven by nonanthropogenic factors in a wide‐ranging migratory mammal,Alaskan caribou

Wide‐ranging mammals face significant conservation threats, and knowledge of the spatial scale of population structure and its drivers is needed to understand processes that maintain diversity in these species. We analysed DNA from 655 Alaskan caribou (Rangifer tarandus granti) from 20 herds that vary in population size, used 19 microsatellite loci to document genetic diversity and differentiation in Alaskan caribou, and examined the extent to which genetic differentiation was associated with hypothesized drivers of population subdivision including landscape features, population size and ecotype. We found that Alaskan caribou are subdivided into two hierarchically structured clusters: one group on the Alaska Peninsula containing discrete herds and one large group on the Mainland lacking differentiation between many herds. Population size, geographic distance, migratory ecotype and the Kvichak River at the nexus of the Alaska Peninsula were associated with genetic differentiation. Contrary to previous hypotheses, small Mainland herds were often differentiated genetically from large interconnected herds nearby, and genetic drift coupled with reduced gene flow may explain this pattern. Our results raise the possibility that behaviour helps to maintain genetic differentiation between some herds of different ecotypes. Alaskan caribou show remarkably high diversity and low differentiation over a broad geographic scale. These results increase information for the conservation of caribou and other migratory mammals threatened by population reductions and landscape barriers and may be broadly applicable to understanding the spatial scale and ecological drivers of population structure in widespread species.     

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.     

Geographic pattern of serum antibody prevalence for Brucella spp. in caribou, grizzly bears, and wolves from Alaska, 1975-1998

Blood samples were collected from 2,635 caribou (Rangifer tarandus), 1,238 grizzly bears (Ursus arctos), and 930 wolves (Canis lupus) from throughout mainland Alaska during 1975-98. Sera were tested for evidence of exposure to Brucella spp. Serum antibody prevalences were highest in the northwestern region of the state. In any specific area, antibody prevalences for caribou and wolves were of a similar magnitude, whereas antibody prevalence for bears in these same areas were two to three times higher.     

Percentage of Fecal Moss in Arctic Ungulates as an Indicator of Wintering Area Quality

Abstract: I investigated local and regional differences in percent moss in the feces of muskoxen (Ovibos moschatus) and reindeer or caribou (Rangifer tarandus) in northwestern Alaska, USA, and related fecal moss to forage availability, snow conditions, animal density, and terrain ruggedness on wintering areas. Reindeer are a partially domesticated form of Rangifer tarandus originating from Europe and Asia and differ physiologically and ecologically from caribou. Percent moss in feces of muskoxen differed locally among individual wintering areas. Because of the large local variation in moss content of muskox feces, regional differences between the 2 study areas were difficult to resolve. Percent of moss in the feces of reindeer–caribou did not differ between wintering areas within the same study area but did differ between study areas. On muskox wintering areas, fecal moss correlated negatively with graminoid cover and snow hardness and positively with moss cover and muskox density, but fecal moss did not correlate with snow depth or terrain ruggedness. On reindeer–caribou wintering areas, fecal moss correlated positively with moss availability but not with lichen cover or snow depth or hardness. Because muskox groups in Alaska are isolated from each other in winter, even groups wintering on neighboring hills may face different foraging availability and might, therefore, exhibit differences in growth or productivity. Reindeer–caribou are more mobile than muskoxen in winter, and fecal samples may not be representative of vegetative and snow conditions at the wintering area where I collected them. I conclude that managers can use fecal moss as an indicator of overgrazed ranges, severe snow conditions, or crowded conditions on muskox wintering areas, but that the association between fecal moss and range conditions has to be drawn with caution for the more mobile reindeer–caribou.     

Muscle fibre growth in undernourished reindeer calves (Rangifer tarandus tarandus L.) during winter.

To study whether moderate under-nutrition causes muscle wasting, reindeer (Rangifer tarandus tarandus L.) calves were fed either pelleted reindeer feed ad libitum (n=8) or restricted amounts of lichens (n=8). The restricted amount was 60% of ad libitum intake of lichens, and the feeding period was 6 weeks preceded by a 2-week adjustment period. Biopsy samples from the middle gluteal muscle (M. gluteus medius) for the analysis of fibre composition and area, as well as for the activity of cathepsin B were taken before the restriction period in November and January, and after the restriction period in April. In all calves the muscle fibre composition remained unchanged during the winter. In the lichen group, the fibre size also remained unchanged, whereas in control calves the cross sectional area of type I and type IIA fibres increased significantly from November to April. Cathepsin B activity decreased in all calves from November to January and remained at that low level for the rest of the study period, which suggests an attenuated rate of protein degradation. These results can be taken as an indication that moderate under-nutrition causes no muscle wasting in reindeer calves, and the decreased availability of nitrogen is partially compensated for by adaptive decrease in protein degradation. Interestingly the adaptive changes in protein metabolism are equally well seen in the well-fed controls as in the undernourished lichen-fed reindeer.     

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.     

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.     

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.     

Serologic and experimental investigations of contagious ecthyma in Alaska

Serologic evidence of contagious ecthyma (CE) was found in domestic sheep (Ovis aries), domestic goats (Capra hircus), Dall sheep (Ovis dalli), and musk-ox (Ovibos moschatus) in Alaska. A moose (Alces alces) calf and a caribou (Rangifer tarandus) fawn were susceptible to experimental infection and both developed antibody titers as a result. CE virus was isolated from lesions of Dall sheep which were involved in a natural outbreak of the disease.     

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.     

Molecular characterization of Cryptosporidium sp. isolated from northern Alaskan caribou (Rangifer tarandus)

Cryptosporidium sp. was found in 3 out of 49 caribou (Rangifer tarandus) from northern Alaska. Segments of both the 18S ribosomal RNA and the heat shock protein genes were amplified from the caribou isolate and compared with that obtained from an isolate from a wild white-tailed deer (Odocoileus virginianus) in Virginia as well as other species and isolates available from GenBank. Analyses showed the white-tailed deer isolate to be identical with the C. parvum cattle genotype; however, the caribou isolate represents a new genotype closely related to C. serpentis, C. muris, and C. andersoni. Giardia sp. was not detected in any of the caribou samples nor was Cryptosporidium sp. or Giardia sp. detected in any of the 42 moose (Alces alces) samples examined.     

Evidence of herpesvirus infection in Woodland Caribou in Saskatchewan

Sera were collected from 40 female and two male woodland caribou (Rangifer tarandus caribou) in Saskatchewan (Canada) from March 1992 to January 1995, inclusive. The samples were examined for antibodies against smooth Brucella spp., five serovars of Leptospira interrogans, bovine viral diarrhea virus, and bovine herpesvirus 1 (BHV-1). Twenty-two (52%) of 42 sera exhibited positive reactions to BHV-1 by a modified serum neutralization test, and the prevalence correlated positively with the age of the animals. No antibodies were detected against the other pathogens. This is the first reported evidence of herpesvirus infection in isolated populations of woodland caribou in western Canada.