The Russian Arctic supports wild sympatric ruminants and their data-deficient helminths. In this study, we: (1) collected fecal samples of wild and semiwild reindeer (Rangifer tarandus), muskoxen ...(Ovibos moschatus), and snow sheep (Ovis nivicola) across Palearctic North territories: Arkhangelsk Oblast (including Novaya Zemlya archipelago), Karelia and Sakha Republics, Kola, Yamal, Taimyr, and Chukotka Peninsulas, Bering, Svalbard, and Wrangel Islands; (2) conducted a coprological survey (noninvasive life-time method preferable for protected animals) to obtain eggs and larvae of helminths inhabiting digestive, respiratory, nervous, and muscular systems; (3) identified helminths according to their morphology and DNA sequences; (4) estimated parasite load per host; (5) analyzed our findings. Varestrongylus eleguneniensis (in reindeer) was reported for the Palearctic for the first time, while Orthostrongylus sp. was reported both for R. tarandus and for the Palearctic for the first time. Capillarid-type eggs were reported for snow sheep for the first time. The question of the role of wild Arctic ruminants as vectors for rotifers was raised.
The reindeer (
L.) is a unique animal inhabitant of arctic regions. Low ambient temperatures and scant diets (primarily, lichens) have resulted in different evolutional adaptations, including the ...composition of the ruminal microbiota. In the study presented here, the effects of seasonal and regional aspects of the composition of the ruminal microbiota in reindeer (Nenets breed, 38 animals) were studied (wooded tundra from the Yamalo-Nenetski Autonomous District (YNAD) vs. from the Nenetski Autonomous District (NAD)). The ruminal content of calves (
= 12) and adult animals (
= 26, 15 males and 11 females) was sampled in the summer (
= 16) and winter seasons (
= 22). The composition of the ruminal microbial population was determined by the V3-V4 16S rRNA gene region sequencing. It was found that the population was dominated by Bacteroidetes and Firmicutes phyla, followed by
and
. An analysis of the community using non-metric multidimensional scaling and Bray-Curtis similarity metrics provided evidence that the most influential factors affecting the composition of ruminal microbiota are the region (
= 0.001) and season (
= 0.001); heat map analysis revealed several communities that are strongly affected by these two factors. In the summer season, the following communities were significantly larger compared to in the winter season:
,
, and
. The following communities were significantly larger in the winter season compared to in summer:
,
spp.,
spp.,
spp.,
spp., and
spp. In NAD (tundra), the following communities were significantly larger in comparison to YNAD (wooded tundra):
(Verruco-5),
, PeHg47
, cellulolytic
, and
spp. The following bacterial groups were significantly larger in YNAD in comparison to NAD: cellulolytic
,
,
, and
spp. The significant differences in the ruminal microbial population were primarily related to the ingredients of diets, affected by region and season. The summer-related increases in the communities of certain pathogens (
,
spp.,
) were found. Regional differences were primarily related to the ratio of the species involved in ruminal cellulose degradation and ruminal fatty acids metabolism; these differences reflect the regional dissimilarities in botanical diet ingredients.
The aim of the work was to compare the taxonomic composition of the rumen procariotic community in young and adult individuals of Nenets breed reindeer (
) from the central part of the Yamal region ...by using the NGS method (next generation sequencing) and compare the microbiome composition of reindeer with the microbiome of their initial vegetation food material. The obtained data showed that the dominant position in microbial communities, like that of other ruminants, was occupied by representatives of phylum
and
, whose total share between observed groups did not differ significantly. The composition of the microbiome of the rumen of the investigated group of animals was completely different from the microbiome structure of the initial vegetation cover. Digestion of vegetation by reindeers resulted in complex transformation in the initial plant microbiome and an increase of biological diversity which was expressed in operational taxonomic unit (OTU) numbers increasing and changes in indexes of alpha-diversity parameters. According to the results of alpha- and beta- diversity of the rumen microbial communities, the greatest uniqueness was revealed for the microbiomes of the adults in comparison with calves and young. The presence of changes in the biodiversity indexes of the rumen microbiota in the reindeer, examined by us, confirm the opinion of the researchers that the microbial community may also reflect the physiological state of the animals. It has also been demonstrated that the presence of the phylum
, and the genera
,
, etc., may be specific to Nenets breed reindeer and have a pattern with their presence on various plants and lichens that are part of the reindeer diet. This is partially confirmed by data on plants microbiome taxonomy.
Abstract
Reindeer digestion is impossible without the symbiotic microorganisms that live in its rumen. The composition of plant fibers present in the diet of reindeer is characterized by an increased ...content of plant fiber, hemicellulose, lignin, and secondary lichen metabolites. The Arctic is characterized by extremely scarce food resources even in summer. In winter the nutritional value of the diet is further reduced. The digestion of such feeds is provided only by the enzyme systems of microorganisms that live in the rumen of ruminants. Therefore, the purpose of our study was to determine the changes occurring in the composition of the reindeer’ rumen bacterial community inhabiting the Nenets region of the Russian Arctic. Rumen contents were collected from 20 reindeer in winter and summer 2017. To identify the bacterial community, 16S rRNA sequencing was used on the MiSeq (Illumina). Statistical processing of the results of NGS using the PERMANOVA analysis showed that the rumen bacterial communities in winter and summer have significant differences (P = 0.001). Taxonomic analysis using the GreenGenes database showed that, in general, at the phylum level in the community, representatives of Firmicutes (29.98–52.67%) and Bacteroidetes (33.55–51.87%) dominated. Significant differences were shown for microorganisms associated with the fermentation of plant polysaccharides. In winter, a significant increase in bacteria of the genera Succiniclasticum (P < 0.001), Paraprevotellaceae (P < 0.001), Coprococcus (P < 0.001), Butyrivibrio (P < 0.001), Prevotella (P < 0.001), Ruminococcus (P < 0.001). Thus, there is a succession of the bacterial community of the reindeer rumen associated with the change of seasons, affecting minor groups of microorganisms. In turn, it is associated with the availability of various components of the diet and the predominance of more or less easily digestible substances in it. The study was supported by a grant of Russian Science Foundation Project No. 17-76-20026.
The Russian Arctic supports wild sympatric ruminants and their data-deficient helminths. In this study, we: (1) collected fecal samples of wild and semiwild reindeer (Rangifer tarandus), muskoxen ...(Ovibos moschatus), and snow sheep (Ovis nivicola) across Palearctic North territories: Arkhangelsk Oblast (including Novaya Zemlya archipelago), Karelia and Sakha Republics, Kola, Yamal, Taimyr, and Chukotka Peninsulas, Bering, Svalbard, and Wrangel Islands; (2) conducted a coprological survey (noninvasive life-time method preferable for protected animals) to obtain eggs and larvae of helminths inhabiting digestive, respiratory, nervous, and muscular systems; (3) identified helminths according to their morphology and DNA sequences; (4) estimated parasite load per host; (5) analyzed our findings. Varestrongylus eleguneniensis (in reindeer) was reported for the Palearctic for the first time, while Orthostrongylus sp. was reported both for R. tarandus and for the Palearctic for the first time. Capillarid-type eggs were reported for snow sheep for the first time. The question of the role of wild Arctic ruminants as vectors for rotifers was raised.
Research objective
To conduct a comparative analysis of the genetic diversity of the Nenets reindeer breed (Rangifer tarandus tarandus) in Russia using a new microsatellite panel.
Material and ...methods used
In total, 228 individuals from four populations of the Nenets (47 samples), Yamalo‐Nenets (151), and Khant‐Mansi (30) regions of the Russian Federation were studied.
The new panel consists of 16 microsatellite loci: 10 dinucleotide loci ‐ Rt6, BMS1788, Rt30, Rt1, Rt9, Rt7, Rt24, FCB193, BMS745, NVHRT16 and 6 tetranucleotide STR markers ‐ OheQ, C217, C32, T40, C276, C143. GeneMapper ID‐X 1.4 software (Applied Biosystems) used to analyze the obtained data. The statistical analysis was performed in the R package, 3.6.1 version (R Core Team, 2019).
Research results
For 16 microsatellite loci 132 alleles were found, from 2 alleles (locus C217) to 16 alleles (locus OheQ). The average number of alleles per locus for all samples was 8.25. The smallest number of alleles per sample was observed in the samples of reindeer from the Nen.NAO and Nen.KhMAO, 103 alleles, and the largest from the Nen.YaNAO, 119. Allelic richness (Ar) ranged from 5.85 to 6.25. For each sample, the distribution of individual inbreeding coefficients f was constructed. We can talk about the presence of inbreeding in all samples, since the high values of f indicate a decrease in the heterozygosity of individual genomes in the samples due to inbreeding. The Polymorphism Information Content (PIC) values were calculated for each pair of “locus‐sample” which were estimated based on the number and frequency of alleles at the locus. The average PIC value turned out not to be very high: 0.613 ± 0.049. The highest levels of polymorphism were obtained for 3 loci: Rt9 (PIC = 0.906), OheQ (PIC = 0.913), and Rt1 (PIC = 0.920).
It is proposed to investigate the polymorphism of microsatellite loci of all four Russian reindeer breeds. The following will be determined for each breed: genetic structure, its effective number, inbreeding coefficient; the degree of differentiation between the breeds has been established. As a result of a detailed analysis we will build a model for the demographic history of the reindeer.
The key natural area of Russian reindeer (
, Nenets breed) is arctic zones, with severe climatic conditions and scarce feed resources, especially in the cold winter season. The adaptation of reindeer ...to these conditions is associated not only with the genetic potential of the animal itself. The rumen microbiome provides significant assistance in adapting animals to difficult conditions by participating in the fiber digestion. The aim of our study is to investigate the taxonomy and predicted metabolic pathways of the ruminal microbiota (RM) during the winter-spring (WS) and summer-autumn (SA) seasons, in calves and adult reindeer inhabiting the natural pastures of the Yamalo-Nenetsky Autonomous District of the Russian Federation.
The RM in reindeer was studied using the Next Generation Sequencing method with the MiSeq (Illumina, San Diego, CA, USA) platform. Reconstruction and prediction of functional profiles of the metagenome, gene families, and enzymes were performed using the software package PICRUSt2 (v.2.3.0).
The nutritional value of WS and SA diets significantly differed. Crude fiber content in the WS diet was higher by 22.4% (
< 0.05), compared to SA, indicating possibly poorer digestibility and necessity of the adaptation of the RM to this seasonal change. A total of 22 bacterial superphyla and phyla were found in the rumen, superphylum Bacteroidota and phylum Firmicutes being the dominating taxa (up to 48.1% ± 4.30% and 46.1% ± 4.80%, respectively); while only two archaeal phyla presented as minor communities (no more then 0.54% ± 0.14% totally). The percentages of the dominating taxa were not affected by age or season. However, significant changes in certain minor communities were found, with seasonal changes being more significant than age-related ones. The percentage of phylum Actinobacteriota significantly increased (19.3-fold) in SA, compared to WS (
= 0.02) in adults, and the percentage of phylum Cyanobacteria increased up to seven-fold (
= 0.002) in adults and calves. Seasonal changes in RM can improve the ability of reindeer to withstand the seasons characterized by a low availability of nutrients. The PICRUSt2 results revealed 257 predicted metabolic pathways in RM: 41 pathways were significantly (
< 0.05) influenced by season and/or age, including the processes of synthesis of vitamins, volatile fatty acids, and pigments; metabolism of protein, lipids, and energy; pathogenesis, methanogenesis, butanediol to pyruvate biosynthesis, cell wall biosynthesis, degradation of neurotransmitters, lactic acid fermentation, and biosynthesis of nucleic acids. A large part of these changeable pathways (13 of 41) was related to the synthesis of vitamin K homologues.
The results obtained improve our knowledge on the structure and possible metabolic pathways of the RM in reindeer, in relation to seasonal changes.
The connection between the types of potassium concentration and the ecogenesis of the studied groups of animals, with the degree of extreme conditions of breeding, with types of potassium in extreme ...conditions of breeding is known. In this regard, studies on autochthonous species of ungulates in the Subarctic are of great interest, the most numerous of which is the reindeer (Rangifer tarandus). Comparative analysis of the adaptive responses of NK and LK types at different levels of organization confirmed the presence of the adaptive advantage of animals characterized by a hereditarily high concentration of potassium in the blood in ecological-geographical zones with extreme environmental conditions. As a result of a study on domesticated reindeer, a clearly expressed dimorphism in the level of potassium in the blood was revealed, due to a genetically controlled high NK and low LK concentration. The average level of potassium in whole blood in the studied population of reindeer is 26.94 ± 0.56 meq/l with a variability of 24.61%. It was revealed that the average level of potassium content in whole blood by sex and age was distributed as follows: whales 22.97 - 25.80 meq/l at P> 0.05, castrate bulls had indicators significantly higher than 28.37 - 29.58 meq / l, at P> 0.05, the young showed intermediate indicators - 27.37 - 28.13 at P> 0.05. The intragroup variability in potassium content in whole blood ranged from 15.5 to 31.05%. It was found that in domestic reindeer the ratio of animals of the high-potassium (HK) type is 88.02% and of the lowpotassium (LK) type - 11.98%, while the gene frequencies for highpotassium animals are 0.9381.
For the first time, comprehensive studies of the phenogenetic features of the Ural ecotype of domestic reindeer of the Nenets breed were performed. It was found out that the Ural reindeer relative to ...other ecotypes of the Nenets breed have smaller linear dimensions and live body weight. The studied group of reindeer was characterized by the minimum values of the majority of population genetic indicators, including the effective number of alleles (Ne = 4.422 ± 0.614), the Shannon information index (I = 1.663 ± 0.102), and the level of both the observed and expected heterozygosity (Ho = 0.561 ± 0.064 and He = 0.740 ± 0.035, respectively). It exceeded two other samples from neighboring breeding regions (Nenets Autonomous district and the Komi Republic) in the average number of alleles per locus: (Na = 9.667 ± 0.577 versus Na = 9.555 ± 0.669 and Na = 9.557 ± 0.709, respectively). Animals of the Ural population (YAM) have a closer genetic structure with reindeer individuals of the neighboring Nenets Autonomous district (NAO). The studied sample of the Nenets breed was characterized by a shift in genetic diversity towards a lack of heterozygotes, as evidenced by the positive Fis values. The introduction of genetic methods in the reindeer herding will allow improving the breeding work in the industry, revealing intraspecific genetic variation in inbreeding herds and identifying intrabreed groups of animals.
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