Adipose gene expression profiles in Northern Finncattle, Mirandesa cattle, Yakutian cattle and commercial Holstein cattle.

The drastic change in global climate has led to in-depth studies of the geneticresources of native cattle adapted to challenging environments. Native cattle breeds may harbor unique genetic mechanisms that have enabled them adapt to their given environmental conditions. Adipose tissues are key factors in the regulation of metabolism and energy balance and are crucial for the molecular switches needed to adapt to rapid environmental and nutritional changes.

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 the membrane of 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 as influenced by cell function, including hematopoiesis.

Brown adipose tissue thermogenesis among a small sample of reindeer herders from sub-Arctic Finland.

Introduction: Interest in human physiological responses to cold stress have seen a resurgence in recent years with a focus on brown adipose tissue (BAT), a mitochondria dense fat specialized for heat production. However, a majority of the work examining BAT has been conducted among temperate climate populations.

Methods: To expand our understanding of BAT thermogenesis in a cold climate population, we measured, using indirect calorimetry and thermal imaging, metabolic rate and body surface temperatures of BAT-positive and BAT-negative regions at room temperature, and mild cold exposure of resting participants from a small sample of reindeer herders (N = 22, 6 females) from sub-Arctic Finland.

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

Reindeer (Rangifer tarandus) are semi-domesticated animals adapted to the challenging conditions of northern Eurasia. Adipose tissues play a crucial role in northern animals by altering gene expression in their tissues to regulate energy homoeostasis and thermogenic activity. Here, we perform 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 spring and winter.

Reindeer herders from subarctic Finland exhibit high total energy expenditure and low energy intake during the autumn herd roundup.

Objective: High levels of total energy expenditure (TEE, kcal/day) have been documented among numerous human populations such as tropical climate horticulturalists and high-altitude agriculturalists. However, less work has been conducted among highly physically active cold climate populations.

Methods: In October 2018, TEE was measured using the doubly labeled water (TEE , N = 10) and flex-heart rate methods (TEE , N = 24) for 6-14 days among reindeer herders (20-62 years) in northern Finland during an especially physically demanding, but not seasonally representative, period of the year for herders-the annual reindeer herd roundup.

Elevated resting metabolic rates among female, but not male, reindeer herders from subarctic Finland.

Objective: Elevated resting metabolic rates (RMR, kcal/day) are a well-established mechanism for maintaining core body temperature among cold climate populations. A high degree of interindividual variation has recently been noted among circumpolar populations. To further examine RMR variability, we investigated anthropometric and metabolic differences among reindeer herders from subarctic Finland.

The effects of wintertime undernutrition on plasma leptin and insulin levels in an arctic ruminant, the reindeer.

We examined the effects of prolonged undernutrition on plasma leptin and insulin levels and some serum protein metabolites in reindeer (Rangifer tarandus tarandus L.) during winter and spring. The reindeer (male <1 year) were fed their preferred winter feed, low-protein lichen ad libitum for 5 weeks, followed by 40% restriction of energy for 8 weeks and refeeding with high-protein pellets for 6 weeks.

Effect of moderate wintertime undernutrition on fatty acid composition of adipose tissues of reindeer (Rangifer tarandus tarandus L.).

We studied the effect of moderate undernutrition on the fatty acid composition of adipose tissues in reindeer calves (<1 year) between early winter and late spring. Calves studied in early winter (December) had grazed on natural pastures and were in good condition, while the calves in spring (April) had been maintained on a negative energy balance since December, had lost approximately 16% of body weight and were in a moderate undernutritional state. The fatty acid composition of total lipids in adipose tissues (perirenal-abdominal, peristernal, scapular, intralumbar, and caudal locations) had a high proportion of oleic acid (35-47%) in both seasons.

The effect of wintertime undernutrition on the fatty acid composition of leg bone marrow fats in reindeer (Rangifer tarandus tarandus L.).

We studied the effects of wintertime undernutrition on the fatty acid composition of bone marrow triacylglycerols (TAGs) of legs in freely-ranging reindeer calves (<1 year) and adult hinds by comparing reindeer in poor condition slaughtered in February with reindeer in good condition slaughtered in October. Significant reductions were found in the proportions of the major monounsaturated fatty acid, or oleic acid, and in linoleic and alpha-linolenic acids in the femur TAGs of the undernourished reindeer as compared with the reindeer in good condition. As a result of these changes, the unsaturation index (UI) of the femur TAGs was reduced by 11% both in the calves and hinds.

The effects of a prolonged undernutrition on serum lipids and fatty acid composition of reindeer calves during winter and spring.

We examined the effects of undernutrition on lipid metabolism in reindeer (<1 year) during mid-winter and spring, with particular focus on the proportions of polyunsaturated fatty acids (PUFAs) in major serum lipids. The reindeer (n=8) were fed their winter feed, lichen, ad libitum for 5 weeks, followed by 40% restriction of energy for 8 weeks and refeeding to normal for 6 weeks. The concentrations of major serum lipids, cholesterol and phospholipids decreased significantly during the ad libitum period (by 50 and 44%, respectively).

Polyunsaturated fatty acids in serum lipids of reindeer during the close postnatal period.

We examined serum fatty acid composition in reindeer during the close postnatal period (from < 8 h to 3 weeks) by using maternal serum as a reference point and focusing on the proportions of polyunsaturated fatty acids (PUFAs) in serum lipids. A striking dissimilarity was found in the serum PUFAs between the neonatals and their mothers. In particular, the proportions of linoleic acid (18:2) and alpha-linolenic acid in serum cholesteryl esters and phospholipids of the newborn reindeer were significantly lower than those of the mothers.

Water intake and its thermal energy cost in reindeer fed lichen or various protein rations during winter.

Captive reindeer were fed four different rations which supplied equal energy but varying amount of crude protein: lichens (3%), mixed hay plus lichens (10%) and two feed concentrates with medium (12%) or high (18%) protein content. Kinetics of total body water were measured with tritiated water from February to March 1985, and thermal energy cost of daily water intake was estimated. Biological half-time of water was shorter, and daily water intake significantly higher on the hay plus lichens diet and on the medium- or high-protein concentrates diet than on the lichens diet during March 1985.

Localization, cellular morphology and respiratory capacity of "brown" adipose tissue in newborn reindeer.

1. The localization and cellular morphology of adipose tissue was studied by light, fluorescence and electron microscopy in reindeer between 2 weeks pre partum and 4.5 months post partum during calving, and the subsequent growth period.

Brown fat-specific mitochondrial uncoupling protein in adipose tissues of newborn reindeer.

Reindeer inhabit a severe arctic or subarctic environment, with the young born in early spring under adverse weather conditions. The extreme northern climate imposes a major thermal challenge to the newborn, and in the present study we have examined fetal, neonatal, and young (from 2 wk before birth to 16 mo postpartum) semidomesticated reindeer from northern Finland for the presence of thermogenic brown adipose tissue. Adipose tissues were removed, mitochondria were prepared, and the proteins were separated by molecular weight and blotted onto nitrocellulose membranes.

The influence of ambient temperature on metabolism and body temperature of newborn and growing reindeer calves (Rangifer tarandus tarandus L.).

Thermoregulatory capacities of 51 reindeer calves (Rangifer tarandus tarandus L.) aged 1-35 days were studied at -26.5 to +35.