Social thermoregulation and huddling bring about energy benefits to animals sharing a nest because of the smaller surface-to- volume ratio of a huddle and the higher local temperature in the nest. We tested whether living in groups and huddling affect daily torpor, metabolic rate and seasonal changes in the body mass of a small heterothermic rodent, the Siberian hamster ( Phodopus sungorus ), housed under semi-natural conditions both singly and in groups of four litter-mates. We predicted that in hamsters housed in groups: (1) synchronized torpor bouts would be longer and deeper than non-synchronized ones but shallower than in solitary hamsters, (2) seasonal variations in metabolic rate would be lower than in solitary hamsters, and (3) the winter decrease in body mass would be smaller in grouped than in singly housed hamsters. We found that group housing led to a smaller decrease in body mass in winter, and affected the length and depth of daily torpor. In group-living hamsters more than 50% of all torpor episodes were synchronized and torpid animals were often found in huddles formed of all cage-mates. The longest and deepest torpor bouts in groups were recorded when all animals in a group entered torpor simultaneously. Although the minimum body temperature during torpor was higher, torpor duration was slightly longer than in solitary hamsters. We did not record significant differences in the body mass-adjusted rate of oxygen consumption between solitary and grouped animals, either in the cold or at the lower critical temperature. We conclude that social thermoregulation enables maintenance of a larger body mass, and thus a larger body fat content, which can ensure better body condition at the beginning of the reproductive season.
FGF21 (LY2405319) treatment. Prior to surgery animals were singly housed to accurately determine food intake. Young (n = 6 per treatment, mean 37.9 ± 1.6 g) and aged Siberian hamsters (n = 5 per treatment, mean 31.1 ± 2.0 g) received a subcutaneously (s.c.) implanted Alzet osmotic mini-pumps (Model 1007D, Charles River) releasing vehicle (saline) or LY (FGF21; 3 mg/kg/day) for 7 days. Mini-pumps were inserted below the skin on the flank of the Siberian hamster under 1.5% isoflurane anaesthesia. Hamsters were treated with analgesic (5 mg/kg s.c., maintained for 3 days with additional fluids, 0.5 ml/day, Rimadyl, Pfizer, Kent, UK) and the wound closed with Michel clips. Body weight and food intake were recorded daily, shortly before lights out. Three days post-surgery the animals were transferred to metabolic cages for a 48 hrs, with the first 24 hrs used as the habitua- tion period and the final 24 hrs for the measurement of the metabolic parameters described below.
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change in RER and therefore no evidence that substrate utilization (carbohydrate vs. fat oxida- tion) was affected. The increase in oxygen consumption 12 weeks post viral infusion was not due to an increase in locomotor activity, as this was similar in AAV-GFP and AAV-VGF-GFP infused animals. We infer that the significant increase in oxygen consumption, and therefore energy expenditure, 12 weeks post viral infusion, particularly during the dark phase, was the main driver for the attenuated body weight gain in AAV-VGF-GFP infused animals. Indeed, hypothalamic over-expression of VGF reduced interscapular white adipose tissue weights, but increased interscapular brown adipose tissue weights, 12 weeks post infusion, which may potentially account for the increased energy expenditure. Interestingly, externally located WAT depots are relatively spared in response to photoperiod change in the Siberian hamster; epididymal WAT demonstrates proportionally greater decreases . This suggests differential sympathetic neural control in WAT depots in this species. There was a small but significant increase in food consumption measured in the home cage in AAV-VGF-GFP infused animals. The increase in cumulative food intake was apparent 3 weeks post infusion and persisted for the 12 week experimental period; this resulted in significantly increased cumulative food intake (grams per g body weight) in the AAV-VGF-GFP infused group. This reflected increased meal duration and intake, as measured in CLAMS at 12 weeks post viral infusion, since meal fre- quency was unaffected. There was no effect on these behavioural parameters 2 weeks post infu- sion. We infer that these increases in food intake were a compensatory mechanism to limit weight loss and maintain energy stores. These observed changes in energy expenditure and food intake were associated with an increase in the hypothalamic contents of the VGF-derived peptides, AQEE, TLQP and NERP-2. These peptides have been shown to be involved regulating energy homeostasis, since ICV administration of TLQP-21 has been shown to reduce food intake in Siberian hamsters  and increase energy expenditure in mice , while ICV infu- sion of NERP-2 in rats was shown to increase energy expenditure and food intake via the orexin system , suggesting opposing roles for these two distinct VGF derived peptides. These func- tional studies conducted with VGF derived peptides in multiple species largely support the phe- notype produced by hypothalamic over-expression of VGF in the Siberian hamster. Both of these VGF derived peptides (TLQP and NERP-2) were increased 12 weeks post viral infusion with AAV-VGF-GFP and may contribute to the observed increase in energy expenditure. Inter- estingly, TLQP-62 is the most prominent VGF derived peptide , whilst AQEE-30 increases
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Based on the findings above, we hypothesized that the winter decrease of phenotypic flexibility of BMR (Boratyn ́ ski et al., 2017) results from MEL-mediated seasonal changes in the magnitude of stress response. We expected that both BMR and CORT concentrations would increase with short-term acclimation to cold and that both would decrease after acclimation to thermoneutral conditions. We also predicted that MEL supplementation 2 h before lights off, which would lengthen the elevated level of MEL concentration at night, mimicking shortening days, would result in decreased phenotypic flexibility of BMR in animals maintained in a long, summer-like photoperiod. Lastly, we expected that reduced phenotypic flexibility of BMR in MEL-treated animals would be correlated with decreased reaction norms for CORT synthesis. To test the above predictions, we designed an experiment with the Siberian hamster [Phodopus sungorus (Pallas 1773)] as a model species in which the same individuals underwent two different treatments, with and without MEL supplementation, which allowed us to estimate the effect of MEL on the reaction norms of BMR and CORT levels. Siberian hamsters are small, photoresponsive rodents that, during seasonal acclimatization, rely on photoperiod (Wiesinger et al., 1989; Scherbarth and Steinlechner, 2010) and develop a distinct winter phenotype characterized by decreased m b , molt to white pelage, regression
Nonhibernating seasonal mammals have adapted to temporal changes in food availability through behavioral and physiological mechanisms to store food and energy during times of predictable plenty and conserve energy during predicted shortage. Little is known, however, of the hypotha- lamic neuronal events that lead to a change in behavior or physiology. Here we show for the first time that a shift from long summer-like to short winter-like photoperiod, which induces physio- logical adaptation to winter in the Siberian hamster, including a body weight decrease of up to 30%, increases neuronal activity in the dorsomedial region of the arcuate nucleus (dmpARC) assessed by electrophysiological patch-clamping recording. Increased neuronal activity in short days is dependent on a photoperiod-driven down-regulation of H3 receptor expression and can be mimicked in long-day dmpARC neurons by the application of the H3 receptor antagonist, cloben- proprit. Short-day activation of dmpARC neurons results in increased c-Fos expression. Tract tracing with the trans-synaptic retrograde tracer, pseudorabies virus, delivered into adipose tissue reveals a multisynaptic neuronal sympathetic outflow from dmpARC to white adipose tissue. These data strongly suggest that increased activity of dmpARC neurons, as a consequence of down-regulation of the histamine H3 receptor, contributes to the physiological adaptation of body weight regu- lation in seasonal photoperiod. (Endocrinology 150: 3655–3663, 2009)
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Olfactory cues play an integral role in the organization of events that mediate reproductive success. In a variety of species, priming pheromones, in particular, are important for ensuring reproductive fitness. To date, very little research has focused on how male-emitted priming pheromones, such as those that regulate the onset of puberty and estrus synchronization in females, affect the reproductive physiology of the female Siberian hamster (Phodopus sungorus sungorus). This lack of research may be due to the physiology of the Phodopus genus; vaginal cytology cannot be used as a reliable indicator of estrus or ovulation. Using a jugular cannulation technique to determine estrous stage by blood analysis of prolactin and luteinizing hormone, we sought to determine if male priming pheromones affect estrous cyclicity in the female Siberian hamster and, if so, whether the production of these priming pheromones is androgen dependent. Our results showed that females exposed to bedding from mature, intact males showed a significantly higher incidence of proestrus 3 days later than did females exposed to the bedding of mature, gonadectomized males. Therefore, we found that not only do male Siberian hamsters emit chemical signals that induce estrus synchronization, but also that this ability is likely to be androgen dependent.
The fundamental components of a coordinated response in physiology are the neurons. In our work we have identified a suite of gene expression changes in different neuronal populations that are likely to be pertinent to seasonal physiology. This includes Mc3r that mediates the action of aMSH on food intake and energy expenditure . In this study we found that SD induced changes Mc3r in two separate neuronal populations (VMH increased, ARC decreased) are abolished in the SD refractory state, by a reversal in expression in the ARC or by an increase in LD in the VMH. This normalizing of Mc3r expression in the VMH may reflect an age dependent increase since the expression is not normalized by a reversal of the SD expression values. However, the significance an age dependent increase in the VMH is not known for hamster physiology. In addition a SD-induced increase in Srif expression in the ARC is decreased to LD values in the SD refractory hamster. Although the decrease of Srif in SD refractory hamsters cannot be separated from an age dependent effect, this decrease is entirely consistent with the return to a LD phenotype, particularly if Srif in the context of photoperiod may be involved in growth related events . These observations coupled with a previous study where we demonstrated that H3r, Vgf and Crabp2 expression in the dmpARC is restored to LD values in refractory hamsters, points to the importance of neuronal genes in establishing the physiology of the SD refractory state. The exception to this so far is RAR and Figure 7. TSH receptor and nestin gene expression in
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The Siberian hamster, Phodopus sungorus, has been used extensively as a robust model of seasonal change which has been used to investigate energy expenditure, reproductive changes, and adiposity (16, 17). The Siberian hamster seasonal change is stimulated by changes in the production of melatonin, which increases during the short day (SD; winter) photoperiod and prompts metabolic and physical changes (18). Upon exposure to SD photoperiods, they reduce their food intake, even if given food ad libitum (19), which reduces their body weight, abdominal fat reserves, and serum leptin levels. In addition, reproductive system regression occurs in both sexes; the testes and epididymal fat pad weights of males and uterine weight of females are mark- edly reduced in SD-exposed animals (20), resulting in decreased levels of circulating sex hormones (21, 22). Conversely, exposure to long day (LD; summer) photoperiods increases appetite and results in lipogenesis, increased body mass, larger reproductive organs, and elevated leptin production. This comprehensive response to photoperiod provides a model to investigate bone growth and remodeling in animals with naturally high and low serum leptin levels.
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Female protein (FP) is a pentraxin of Syrian hamster which is a homologue of two human pentraxins, C-reaction protein (CRP) and amyloid P component (AP). Functionally, FP has been shown to be similar to CRP, although FP has more homology at the amino terminus with AP. The present work investigated amyloid in the Syrian hamster to determine whether FP was involved in a manner analogous to AP. FP was found to be a constituent of Syrian hamster amyloid. This conclusion was based on the following results: (a) FP was
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The Bio14.6 hamster is an excellent LGMD animal model for muscle force deficit studies and for gene therapy strategy development. The dystrophic TA muscle displays significant deficiency in muscle strength. Thus, the specific twitch force and tetanic force are 59 and 68% of those of the wild-type hamster, respectively. In addition, the TA muscle also dis- played extensive central nucleation and pathological hypertro- phy, which are common signs of dystrophy. Furthermore, this muscle is large enough to readily perform intramuscular vector injection but small enough to carry out in vitro contractile force measurement. Nonetheless, the TA muscle in the Bio14.6 hamster does not seem ideal for an in vivo myofiber membrane leakage test, because in vivo administration of Evans Blue dye did not reveal significant myofiber leakage under the unstressed condition (data not shown and references 8 and 31). On the contrary, the gastrocnemius muscle endured much more significant cell membrane leakage under the same unstressed condition (12). Due to the large size and large force generated beyond our instrument scale, we could not deter- mine whether the gastrocnemius muscle suffers more force deficits than the TA muscle or how much contractile force the former recovers after AAV vector treatment (17).
Results: This research results showed which right hamster ovary had 5/08±1/6mm in length, 3/05 ± 0/56 mm in wide ,and 2/88 ± 0/327 mm in diameter and left ovary had 4/68 ± 1/253 mm in length, 2/2 ± 0/703 mm in wide and 2/4 ± 0/609 mm in diameter. Countering of different type of hamster ovarian follicles were showed which number of primordial follicles were 1628/33± 305/6049, number of primary follicles were 307/33 ± 56/76, number of secondary follicles were 140 ± 60/63, number of tertiary follicles were 9± 0 and number of graafian follicles were 8 ± 3/6. Total count of hamster ovarian follicles was 2192/66± 178/46. Histological studies showed which covering epithelium, parenchyma of hamster ovary is similar to another mammal, and zuna plucida is forming in primary follicles when two cuboidal cell layers are observed around oocytes.
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Geology of the New Siberian Islands supports the cir- cum Arctic Phanerozoic fold belt concept (Egiazarov, 1977; Zhamoida et al., 1989). The belt comprises Caledonian, Ellesmerian, Early Cimmerian and Late Cimmerian fold sys- tems, manifested in many places on the mainland and on is- lands around the Arctic Ocean. Early Paleozoic sequences on the De Long Islands belong to the Caledonian fold system along with Axel Heiberg and northern Ellesmere Island in the Arctic Canada, Spitzbergen, and northern Norwegian Cale- donides. Metamorphic and granite clasts present on Henri- etta and Jeannette islands indicate a provenance area with exposed crystalline basement not far away. It could be a margin of the Hyperborean Platform, now destroyed by the evolving Arctic Basins, or ancient terranes within Caledo- nian mobile belt. The Anjou and Lyakhov Islands are un- doubtedly the westernmost extremity of the Late Cimmerian fold system traced here from the Brooks Range in Alaska through Chukotka. The fold system comprises South Anyui ophiolite suture and pre-collisional trough exposed on the Lyakhov Islands, and moderately folded and faulted Paleo- zoic and Mesozoic sequences of its outer zone known on Ko- tel’ny Island. The South Anyui ophiolite suture terminates within the Bol’shoi Lyakhov area according to the anoma- lous magnetic field pattern. The presence of relict Caledo- nian units reworked in the course of the Late Cimmerian tec- tonism on Bol’shoi Lyakhov Island is very hypothetical but not out of the question. It is questionable whether evidence for Ellesmerian and Early Cimmerian orogeny will be found on the New Siberian Islands, although they may project into the East Siberian Sea shelf from the east. The thick Devo- nian turbidite unit on Wrangel Island (Kos’ko et al., 1993) and Middle to Upper Devonian marginal sea sediments and volcanics on Chukotka (Natal’in et al., 1999) document rem-
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Role of the spleen in neuroinvasion. In mice, the spleen is infected after peripheral scrapie infection, and for some scrapie strains, amplification of infectivity in the spleen may be necessary before neuroinvasion can occur. In the present ex- periments infectivity was analyzed indirectly by testing spleen homogenates for abnormal proteinase K-resistant PrP (PrP- res) by Western blotting. In NSE-HaPrP/MoPrP(⫺/⫺) mice infected i.p. with hamster strain 263K, a possible PrP-res band was detected at very low levels in the spleen at the time of clinical disease (Fig. 3). The amount of PrP-res in this spleen- derived band was 100- to 200-fold lower than in the brain. However, it was not clear from this result whether this low- level accumulation of PrP-res in the spleen was required for neuroinvasion. Therefore, the role of the spleen in the present Tg mouse system was analyzed directly by splenectomy. NSE- HaPrP/MoPrP(⫺/⫺) mice and Tg7-HaPrP/MoPrP(⫺/⫺) mice were splenectomized 10 to 14 days prior to i.p. infection with the 263K strain of hamster scrapie. In these experiments, sple- nectomy failed to significantly alter the range of incubation periods seen in either line of Tg mice (Fig. 2, bottom), which indicated that in this system spleen cells were not needed either as amplifiers of peripheral scrapie infection or as trans- porters of the infectivity to the CNS.
Another set of photographs comes from three Mongolian passengers who were travelling from Ulaan Baatar to Guangzho via Beijing, for part holiday, part business. When asked whether they enjoyed travelling by train they answered: “Outside you have vast landscapes, which broaden your horizon. Inside you have the space to take a walk.” I am still waiting for most of the cameras to make their way back to me and I do not know how many will make it. Those I have received have not been titled and the interviews I have on tape are yet to be fully translated. There is still work to do and the language barrier does indeed present quite a challenge. As with all participatory projects, the process (getting there) is often as interesting as the end result (destination). The Trans-Siberian Photo Project was based on a model of another project I did in 2004 in the East London Council-owned apartment building where I live. In The Broadway House Photo Project, 1 I circulated a single disposable camera around my building, asking residents to take three photographs from and within their flats, (one looking North, one looking South and a third picture of what they wanted inside their homes) and to give their pictures titles. One in five flats in the building took part. The project culminated in an exhibition at a gallery five minutes’ walk away, where my neighbours got to see their photographs for the first time, as well as to meet each other, also in many cases for the first time, despite several having lived in Broadway House for more than twenty years.
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of anemia. In 1989, US Food and Drug Administration (FDA) approved its use in this circumstance. Several other approvals including European and Japanese approvals were also been obtained for this purpose (Diane M. Ridley, 1994). It quickly proved to be useful in treating several types of anemia and polycythemia as well. Accordingly, the need for its industrial scale production increased and large scale biopharmaceuticals started producing RHuEPO for treating these human diseases. There are several cultural systems available for production of RHuEPO. The most widely use system for its production is mammalian cell culture system. RHuEPO is produced commercially by using Chinese Hamster Ovary (CHO) cells. Methylotropic yeast such as Pichia Pastoris is also been in use by some small scale industries for RHuEPO production. Plant culture techniques are not yet been exploited for its industrial production but are immensely under consideration. Mammalian culture system is the biggest industrial system for production of recombinant human erythropoietin. Immortalized Chinese Hamster Ovary (CHO) cells are usually used for this purpose (Kim JY, 2012). Baby Hamster Kidney (BHK) and Human HT 1080 cell lines are also in commercial use for production of RHuEPO. Mammalian cells were the first ones to be used commercially for the production of recombinant proteins including erythropoietin. The reason behind is that fully functional glycosylated and properly folded proteins can be produced in them easily (Hossler P, 2009; Son YD, 2011). Because the erythropoietin is to be used by mammals (humans), mammalian post- translational modifications could be done naturally. Also at that time in the earlier 1980’s, it was not possible to glycosylated these proteins in other systems. Productivity rates in earlier days was 0.1 to 1 pg/cell/day (Wurm F, 1999) in 1990’s but now with some optimizations and advances, productivity rates of 20-60 pg/cell/day is quiet possible to obtain (Arnold L Demain, 2009).
However, in reality, given the stand density, the dif- ference is considerably smaller, since the low yields of individual trees are compensated for by their large number per unit of area; thus, the difference in total seed productivity is smoothed out. In this regard, in- teresting data were obtained during the thinning of Siberian pine saplings with the aim of forming a PFSO in the Novosibirsk region (Kulakov 2004). Despite the different stand density, the same number of Sibe- rian pines give seeds. In the first plot of 400 trees, 70% entered the generative phase, i.e. 280 trees·ha –1 , and in
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been shown by others to accumulate few mutations despite intense selective pressure, indicating that the virus can tolerate minimal sequence variation (8, 11, 34). The mutations that accumulated during virus passage were not evenly distributed throughout the genome (Table 2). Mutations tended to accu- mulate in specific regions of the genome (specifically the E, NS2A, and NS4B protein genes and the 3⬘NCR) regardless of the selective pressure applied. This is evidenced by the fact that vaccine strains 17D and FNV, as well as the attenuated strain Asibi-HeLa p6, share the same nucleotides and amino acid residues with the hamster viscerotropic Asibi/hamster p7 virus at a number of positions despite selection by passaging in different hosts, namely, chicken, mouse, and human HeLa cells, respectively (8, 11, 34) (Table 1). Many of these shared mutations fall within the E protein gene (7, 8, 11, 27, 34). The accumulation of mutations at the same positions despite varied selective pressures indicates that YF virus can tolerate muta- tion only at certain nucleotide or amino acid positions, and these positions are clustered in the E protein gene, NS2A, and NS4B.
In order to detect of TBEV in Mongolia, Ixodes persulcatus ticks were collected from Eruu sum, Selenge aimag and categorized into pools. Each pool was mixed with sterile PBS and homogenized with a sterile mortar and pestle. The homogenate was centrifuged and the collected supernatant was inoculated into baby hamster kidney (BHK-21) cell line. Cytopathic effects (CPE) in the cell line was observed by light microscopy daily. RNA was extracted from supernatant of cells with CPE and confirmed by RT-PCR using specific primer for the Siberian subtype. The present results were indicated that TBEV in Mongolia was belonged to the Siberian subtype.
Animal housing. Adult male animals were obtained from a colony of Siberian hamsters (Phodopus sungorus) maintained at the University of Nottingham Biomedical Services Unit (Ebling 1994). All studies were carried out in accordance with the UK Animals (Scientific Procedures) Act of 1986 (project licence: PPL 40/3604) and approved by the University of Nottingham Animal Welfare and Ethical Review Board. Hamsters were group housed at approximately 21 o C and 40% humidity, and were allowed ad libitum access to water and standard laboratory chow comprising of 19% protein, 45% carbohydrate, 9% fat (Teklad 2019, Harlan, UK). Animals were housed from birth in long day conditions (LD) of 16 hours light: 8 hours dark with lights off at 11:00 GMT.
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number of region pairs belonging to a respective group to the total number of pairs from Table 1. Integration of Siberian regional markets is fairly strong: they are integrated – perfectly and conditionally – with 63.3% of country’s regions (including the Siberian regions themselves). Adding converging region pairs, we get the total of 68.4%. (However, divergence – with 7.9% of Russian regions – takes place as well.) Denote such a figure (lines ‘Sum’ in Table 2) as the integration rate. Individual regions of Siberia are also rather strongly integrated with the rest regions of the country. Their integration rates range from 62.8% to 88.5%. The exceptions are two weakly integrated regions, namely, the Republic of Altai and Novosibirsk Oblast, where the integration rates are equal to 38.5% and 44.9%, respectively.
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