Biology subjects

Soppela, P.

Publications and source records attributed to Soppela, P..

3 recordsLinked to original sources

bioRxiv2023

Whole genome sequencing provides novel insights into the evolutionary history and genetic adaptations of reindeer populations in northern Eurasia

Semi-domestic reindeer (Rangifer tarandus tarandus) play a vital role in the culture and livelihoods of indigenous people across the northern Eurasia. These animals are well adapted to harsh environmental conditions, such as extreme cold, limited feed availability and long migration distances. Therefore, understanding the genomics of reindeer is crucial for improving their management, conservation, and utilization. Here we have generated a new genome assembly for the Fennoscandian semi-domestic reindeer with high contiguity, making it the most complete reference genome for reindeer to date. The new genome assembly was utilized to explore genetic diversity, population structure and selective sweeps in Eurasian Rangifer tarandus populations which was based on the largest population genomic dataset for reindeer, encompassing 58 individuals from diverse populations. Phylogenetic analyses revealed distinct gene clusters, with the Finnish wild forest reindeer standing out as a unique sub-species. Divergence time estimates suggested a separation of [~]52,000 years ago between Northern-European Rangifer tarandus fennicus and Rangifer tarandus tarandus. Our study identified three main genetic clusters: Fennoscandian, the eastern/northern Russian and Alaskan group, and the Finnish forest reindeer. Furthermore, two independent reindeer domestication events were inferred suggesting separate origins for the semi-domestic Fennoscandian and eastern/northern Russian reindeer. Notably, shared genes under selection, including retroviral genes, point towards molecular domestication processes that aided adaptation of this species to diverse environments.

genomics↗

bioRxiv2022

Thermal adaptation and fatty acid profiles of bone marrow and muscles in mammals: implications of a study of caribou (Rangifer tarandus caribou)

Mammals have evolved several physiological mechanisms to cope with changes in ambient temperature. Particularly critical among them is the process of keeping cells in a fluid phase to prevent metabolic dysfunction. In this paper, we examine variation in the fatty acid composition of bone marrow and muscle tissues in the cold-adapted caribou (Rangifer tarandus caribou) to determine whether there are systematic differences in fatty acid profiles between anatomical regions that could potentially be explained by thermal adaptation. Our results indicate that the bone marrow and muscle tissues from the appendicular skeleton are more unsaturated than the same tissues in the axial skeleton, a finding that is consistent with physiological adaptation of the appendicular regions to thermal challenges. Because mechanisms of thermal adaptation appear to be widely shared among terrestrial mammals, we suggest that the same patterns may prevail in other species, possibly including humans.

zoology↗

bioRxiv2021

Adipose gene expression profiles reveal novel insights into the adaptation of northern Eurasian semi-domestic reindeer (Rangifer tarandus)

Reindeer (Rangifer tarandus) are semi-domesticated animals adapted to the challenging arctic conditions of northern Eurasia. Adipose tissues play a crucial role in animals living in northern environments by altering gene expression in their tissues to regulate energy homeostasis and thermogenic activity. Here, we performed transcriptome profiling by RNA sequencing of adipose tissues from three different anatomical depots: metacarpal (bone marrow), perirenal, and prescapular fat in Finnish and Even reindeer (in Sakha) during two seasonal time points (spring and winter). On average 36.5 million pair-ended clean reads were obtained for each sample, and a total of 16,362 genes were expressed in our data. Gene expression profiles in metacarpal tissue were distinct and clustered separately from perirenal and prescapular adipose tissues. Notably, metacarpal adipose tissue appeared to have a significant role in the regulation of the energy metabolism of reindeer in spring when their nutritional condition is poor after winter. During spring, when the animals are in less optimal condition, genes associated with the immune system (e.g., CCL2, CCL11, CXCL14, IGSF3, IGHM, IGLC7, IGKC, JCHAIN, and IGSF10) were upregulated in the perirenal and prescapular adipose tissue, while genes involved in energy metabolism (e.g., ACOT2, APOA1, ANGPTL1, ANGPTL8, ELOVL7, MSMO1, PFKFB1, and ST3GAL6) were upregulated in metacarpal tissue. Even reindeer harboured relatively fewer significantly differentially expressed genes than Finnish reindeer, irrespective of the season, possibly owing to climatic and management differences. Moreover, blood and tissue parameters reflecting general physiological and metabolic status showed less seasonal variation in Even reindeer than in Finnish reindeer. This study identified adipose candidate genes potentially involved in immune response, fat deposition, energy metabolism, development, cell growth, and organogenesis. Taken together, this study provides new information on the mechanisms by which reindeer adapt to less optimal arctic conditions.

genomics↗