Explore the vast range of titles available.

Background Brown adipose tissue (BAT) is the main site of non-shivering thermogenesis (NST) in small mammals, playing an important role in maintaining body temperature and energy balance. Huddling is a behavioral strategy for small rodents to save energy and improve the survival under cold environments. However, the way of huddling behavior influence on hypothalamus, which regulate BAT thermogenesis in small mammals is rarely illustrated. We used male Brandt’s voles ( Lasiopodomys brandtii ) to explore the possible regulation mechanisms in BAT thermogenesis by the way of cold acclimation and huddling behavior. Results There is a strong relationship between huddling behavior and NST in BAT. The hypothalamus, which is impacted by huddling behavior, influences PPAR signaling pathway in the BAT, and induces thermogenesis through Calcium signaling pathway. PPAR pathway causes crosstalk among NF-κB signaling pathway, Thermogenesis and Fatty acid metabolism to perform functions for thermogenesis. Conclusions The results suggest that huddling behavior can modulate adaptive thermogenesis in BAT. Cold acclimation and huddling had a synergistic effect on the regulation of thermogenic function, the hypothalamus mediates thermogenic changes in BAT induced by huddling behavior. In BAT, the specific pathway of thermogenesis is as follows: TRAF6-PPARγ-UCP1-SUCLG1.

Rodent pests can inflict devastating impacts on agriculture and the environment, leading to significant economic damage associated with their high species diversity, reproductive rates and adaptability. Fertility control methods could indirectly control rodent pest populations as well as limit ecological consequences and environmental concerns caused by lethal chemical poisons. Brandt's voles, which are common rodent pests found in the grasslands of middle-eastern Inner Mongolia, eastern regions of Mongolia, and some regions of southern Russia, were assessed in the present study. We evaluated the effects of a 2-mg/kg dose of levonorgestrel and quinestrol and a 1:1 mixture of the two (EP-1) on reproductive behavior as well as changes in the reproductive system, reproductive hormone levels, and toxicity in Brandt's voles. Our results revealed that all three fertility control agents can cause reproductive inhibition at a dosage of 2 mg/kg. However, quinestrol caused a greater degree of toxicity, as determined by visible liver damage and reduced expression of the detoxifying molecule CYP1A2. Of the remaining two fertility control agents, EP-1 was superior to levonorgestrel in inhibiting the secretion of follicle-stimulating hormone and causing reproductive inhibition. We believe that these findings could help promote the use of these fertility control agents and, in turn, reduce the use of chemical poisons and limit their detrimental ecological and environmental impacts.

Ambient temperature is an important factor influencing many physiological processes, including antioxidant defense and immunity. In the present study, we tested the hypothesis that antioxidant defense and immunity are suppressed by high and low temperature treatment in Brandt's voles (Lasiopodomys brandtii). Thirty male voles were randomly assigned into different temperature groups (4, 23, and 32 °C, n=10 for each group), with the treatment course lasting for 27 d. Results showed that low temperature increased gross energy intake (GEI) and liver, heart, and kidney mass, but decreased body fat mass and dry carcass mass. With the decline in temperature, hydrogen peroxide (H2O2) concentration, which is indicative of reactive oxygen species (ROS) levels, increased in the liver, decreased in the heart, and was unchanged in the kidney, testis, and small intestine. Lipid peroxidation indicated by malonaldehyde (MDA) content in the liver, heart, kidney, testis, and small intestine did not differ among groups, implying that high and low temperature did not cause oxidative damage. Similarly, superoxide dismutase (SOD) and catalase (CAT) activities and total antioxidant capacity (TAOC) in the five tissues did not respond to low or high temperature, except for elevation of CAT activity in the testis upon cold exposure. Bacteria killing capacity, which is indicative of innate immunity, was nearly suppressed in the 4 °C group in contrast to the 23 ° C group, whereas spleen mass and white blood cells were unaffected by temperature treatment. The levels of testosterone, but not corticosterone, were influenced by temperature treatment, though neither were correlated with innate immunity, H2O2 and MDA levels, or SOD, CAT, and TAOC activity in any detected tissues. Overall, these results showed that temperature had different influences on oxidative stress, antioxidant enzymes, and immunity, which depended on the tissues and parameters tested. Up-regulation or maintenance of antioxidant defense might be an important mechanism for voles to survive highly variable environmental temperatures.

Cold commonly affects growth and reproductive development in small mammals. Here, we test the hypothesis that low ambient temperature will affect growth and puberty onset, associated with altered hypothalamic Kiss-1 gene expression and serum leptin concentration in wild rodents. Male Brandt’s voles ( Lasiopodomys brandtii ) were exposed to cold (4 ± 1 °C) and warm (23 ± 1 °C) conditions from the birth and sacrificed on different developmental stages (day 26, day 40, day 60, and day 90, respectively). Brandt’s voles increased the thermogenic capacity of brown adipose tissue, mobilized body fat, decreased serum leptin levels, and delayed the reproductive development especially on day 40 in the cold condition. They increased food intake to compensate for the high energy demands in the cold. The hypothalamic Kiss-1 gene expression on day 26 was decreased, associated with lower wet testis mass and testis testosterone concentration on day 40, in the cold-exposed voles compared to that in the warm. Serum leptin was positively correlated with body fat, testis mass, and testosterone concentration. These data suggested that cold exposure inhibited hypothalamic Kiss-1 gene expression during the early stage of development, decreased serum leptin concentration, and delayed reproductive development in male Brandt’s voles.

Gut microbiota play a critical role in orchestrating metabolic homeostasis of the host. However, the crosstalk between host and microbial symbionts in small mammals are rarely illustrated. We used male Brandt’s voles ( Lasiopodomys brandtii ) to test the hypothesis that gut microbiota and host neurotransmitters, such as norepinephrine (NE), interact to regulate energetics and thermogenesis during cold acclimation. We found that increases in food intake and thermogenesis were associated with increased monoamine neurotransmitters, ghrelin, short-chain fatty acids, and altered cecal microbiota during cold acclimation. Further, our pair-fed study showed that cold temperature can alter the cecal microbiota independently of overfeeding. Using cecal microbiota transplant along with β3-adrenoceptor antagonism and PKA inhibition, we confirmed that transplant of cold-acclimated microbiota increased thermogenesis through activation of cAMP–PKA–pCREB signaling. In addition, NE manipulation induced a long-term alteration in gut microbiota structure. These data demonstrate that gut microbiota-NE crosstalk via cAMP signaling regulates energetics and thermogenesis during cold acclimation in male Brandt’s voles.

Photoperiod regulates spermatogenesis in seasonal breeders, yet its molecular mechanisms remain unclear. The Wnt signaling pathway is critical for spermatogenesis in non-seasonal breeders, but its role in photoperiodic spermatogenesis in seasonal breeders is unexplored. To investigate this, we exposed male Brandt’s voles ( Lasiopodomys brandtii ), a strict seasonal breeder, to long-photoperiod (LP, 16L:8D) and short-photoperiod (SP, 8L:16D) from the embryonic stage. Testis volume was markedly larger in LP than in SP from 4 to 10 weeks after birth. RNA-seq analysis of 151 Wnt pathway genes revealed differential expression, with Wnt5a , Wnt6 , Wnt7a, and Wnt9a downregulated and Wnt7a upregulated in LP compared to SP. RT-qPCR and Western blotting confirmed these patterns. Immunofluorescence analysis showed that WNT7A and WNT9A were localized to pachytene and diplotene spermatocytes at 4 weeks and to elongating spermatid heads at 10 weeks. WNT6 and WNT5A appeared as perinuclear foci in early spermatocytes at 4 weeks, with WNT6 subsequently shifting to spermatid nuclei at 10 weeks. These findings indicate that prenatal and postnatal photoperiodic exposure, potentially mediated through both maternal and direct pathways, is associated with distinct spatiotemporal expression patterns of WNT5A, WNT6, WNT7A, and WNT9A, suggesting their potential involvement in seasonal reproduction.

Mammals dwelling at different altitudes exhibit distinct molecular mechanisms to adapt to low-oxygen environments owing to habitat-specific oxygen levels. Notably, these adaptations include energy metabolism patterns, which fundamentally sustain vital physiological functions. Skeletal muscle, a pivotal contributor to systemic energy metabolism, facilitates vertebrate body movement through the contraction and relaxation of muscle fibers and is highly dependent on mitochondrial substrate oxidation for energy production. This study focused on three rodent species inhabiting different altitudes: the Qinghai vole ( Neodon fuscus ), Brandt’s vole ( Lasiopodomys brandtii ), and Kunming mouse ( Mus musculus ). Using transcriptomics and quasi-targeted metabolomics, we systematically analyzed the differences in skeletal muscle metabolic regulation among the three rodent species before and after exposure to hypoxia, thereby revealing the underlying molecular mechanisms. In summary, N. fuscus , native to high-altitude environments, tended to sustain energy supplies through regulating fatty acid oxidation under low-oxygen conditions. Conversely, L. brandtii and M. musculus , acclimatized to middle- and low-altitude habitats, relied on aerobic oxidation and anaerobic glycolysis of glucose, respectively, for energy maintenance under hypoxic conditions. In addition to their differential metabolic preferences under hypoxic conditions, these three rodent species showed species-specific responses related to oxygen utilization, antioxidant defense mechanisms, and anti-inflammatory processes. This study provides insights into the metabolic response patterns of mammalian skeletal muscle under hypoxic conditions, thereby establishing a basis for future investigations on transcriptional–metabolic associations. Graphical abstract

Background Seasonal breeding in mammals has been widely recognized to be regulated by photoperiod, but the association of gut microbiota with photoperiodic regulation of seasonal breeding has never been investigated. Results In this study, we investigated the association of gut microbiota with photoperiod-induced reproduction in male Brandt’s voles ( Lasiopodomys brandtii ) through a long-day and short-day photoperiod manipulation experiment and fecal microbiota transplantation (FMT) experiment. We found photoperiod significantly altered reproductive hormone and gene expression levels, and gut microbiota of voles. Specific gut microbes were significantly associated with the reproductive hormones and genes of voles during photoperiod acclimation. Transplantation of gut microbes into recipient voles induced similar changes in three hormones (melatonin, follicle-stimulating hormone, and luteinizing hormone) and three genes (hypothalamic Kiss-1 , testicular Dio3 , and Dio2/Dio3 ratio) to those in long-day and short-day photoperiod donor voles and altered circadian rhythm peaks of recipient voles. Conclusions Our study firstly revealed the association of gut microbiota with photoperiodic regulation of seasonal breeding through the HPG axis, melatonin, and Kisspeptin/GPR54 system. Our results may have significant implications for pest control, livestock animal breeding, and human health management. AePJyLnNVHUZSJ5RxTkzzw Video Abstract

Life history theory assumes there are trade-offs between competing functions such as reproduction and immunity. Although well studied in birds, studies of the trade-offs between reproduction and immunity in small mammals are scarce. Here we examined whether reduced immunity is a consequence of reproductive effort in lactating Brandt's voles (Lasiopodomys brandtii). Specifically, we tested the effects of lactation on immune function (Experiment I). The results showed that food intake and resting metabolic rate (RMR) were higher in lactating voles (6≤ litter size ≤8) than that in non-reproductive voles. Contrary to our expectation, lactating voles also had higher levels of serum total Immunoglobulin G (IgG) and anti-keyhole limpet hemocyanin (KLH) IgG and no change in phytohemagglutinin (PHA) response and anti-KLH Immunoglobulin M (IgM) compared with non-reproductive voles, suggesting improved rather than reduced immune function. To further test the effect of differences in reproductive investment on immunity, we compared the responses between natural large (n≥8) and small litter size (n≤6) (Experiment II) and manipulated large (11-13) and small litter size (2-3) (Experiment III). During peak lactation, acquired immunity (PHA response, anti-KLH IgG and anti-KLH IgM) was not significantly different between voles raising large or small litters in both experiments, despite the measured difference in reproductive investment (greater litter size, litter mass, RMR and food intake in the voles raising larger litters). Total IgG was higher in voles with natural large litter size than those with natural small litter size, but decreased in the enlarged litter size group compared with control and reduced group. Our results showed that immune function is not suppressed to compensate the high energy demands during lactation in Brandt's voles and contrasting the situation in birds, is unlikely to be an important aspect mediating the trade-off between reproduction and survival.

The generic status of Lasiopodomys and its division into subgenera Lasiopodomys (L. mandarinus, L. brandtii) and Stenocranius (L. gregalis, L. raddei) are not generally accepted because of contradictions between the morphological and molecular data. To obtain cytogenetic evidence for the Lasiopodomys genus and its subgenera and to test the autosome to sex chromosome translocation hypothesis of sex chromosome complex origin in L. mandarinus proposed previously, we hybridized chromosome painting probes from the field vole (Microtus agrestis, MAG) and the Arctic lemming (Dicrostonyx torquatus, DTO) onto the metaphases of a female Mandarin vole (L. mandarinus, 2n = 47) and a male Brandt's vole (L. brandtii, 2n = 34). In addition, we hybridized Arctic lemming painting probes onto chromosomes of a female narrow-headed vole (L. gregalis, 2n = 36). Cross-species painting revealed three cytogenetic signatures (MAG12/18, 17a/19, and 22/24) that could validate the genus Lasiopodomys and indicate the evolutionary affinity of L. gregalis to the genus. Moreover, all three species retained the associations MAG1bc/17b and 2/8a detected previously in karyotypes of all arvicolins studied. The associations MAG2a/8a/19b, 8b/21, 9b/23, 11/13b, 12b/18, 17a/19a, and 5 fissions of ancestral segments appear to be characteristic for the subgenus Lasiopodomys. We also validated the autosome to sex chromosome translocation hypothesis on the origin of complex sex chromosomes in L. mandarinus. Two translocations of autosomes onto the ancestral X chromosome in L. mandarinus led to a complex of neo-X1, neo-X2, and neo-X3 elements. Our results demonstrate that genus Lasiopodomys represents a striking example of rapid chromosome evolution involving both autosomes and sex chromosomes. Multiple reshuffling events including Robertsonian fusions, chromosomal fissions, inversions and heterochromatin expansion have led to the formation of modern species karyotypes in a very short time, about 2.4 MY.