Nervous system ganglioside composition of normothermic and hibernating dormice (Glis glis)

The ganglioside pattern of seven different regions, olfactory bulb, forebrain cortex, midbrain (corpora quadrigemina), cerebellum, brain stem, pons and spinal cord, of nervous system of normothermic and hibernating dormice (Glis glis) were investigated by two dimensional thin layer chromatography and densitometric quantification. Up to thirty different ganglioside spots were resolved, fifteen of which belonging to alkali labile species. Alkali labile gangliosides were present in all the regions obtained from normothermic animals, and their content, expressed as percentage of total ganglioside-bound sialic acid, ranged from a minimum of 10.2% in olfactory bulb, to a maximum of 30.1% in spinal cord. The most abundant alkali labile gangliosides were O-Ac-GT1b, O-Ac-GQ1b and an unidentified one, we coded I3. Alkali labile gangliosides were practically undetectable in hibernating dormice. They could be recognized only in brain stem, 3.3% and olfactory bulb, 0.6%.     

Seasonal changes in liver size in edible dormice (Glis glis): non-invasive measurements using ultrasonography

We used non-invasive ultrasonography to investigate seasonal changes in liver size of an obligate hibernator; the edible dormouse (Glis glis). We repeatedly measured liver size in dormice at two study sites, (1) an enclosure-housed colony and (2) a free-ranging population. We observed a significant increase in transverse liver size throughout the active season; however, this effect was most pronounced in animals with low body mass early in the active season. Ultrasonography imaging revealed that the content of fat in the liver (distributed in an unexpected pattern of discrete focal areas) visibly increased at the end of the active season both in the field and enclosure. Thus, the observed increase in liver size of dormice seems mainly related to fat accumulation. We found no principal differences in the time courses of transversal liver size between the two study sites. Our results support the view that non-invasive ultrasonography is an accurate method to study internal organ sizes, such as liver, in the laboratory and in the field.     

Pituitary β-endorphin content during spontaneous food intake and body weight cycles in the dormouse, Glis glis

Pituitary β-endorphin content was measured in dormice during several distinct phases of the infradian body weight cycle. No significant differences in opiate content among groups were found. It appears unlikely that pituitary concentrations of β-endorphin have etiological significance in the development of spontaneous obesity in hibernators.     

新疆准噶尔盆地北缘晚渐新世睡鼠再研究（英文）

周氏似日本睡鼠Gliruloides zhoui是发现于新疆准噶尔盆地北缘晚渐新世铁尔斯哈巴合哺乳动物组合I带的一个化石新属种。新属似日本睡鼠Gliruloides的属征为:中等大小;颊齿咀嚼面凹;上、下颊齿通常具9条主要横脊,有时具次级附脊;上颊齿的前边附脊和后边附脊以及下颊齿的下前边附脊和下后边附脊都很发育,几乎占据了其所在齿谷的整个长度。上颊齿的横脊唇端趋于游离。M1和M2具V形或窄U形三角座,内脊不完整或近于完整,前中央脊不与内脊相连。下颊齿的下内脊通常不连续;下臼齿的下前边脊在唇端稍向后弯,但不与原尖相连。p4,m1-m3,P4,M1-M3的齿根数分别为2,2,3,3。新属与Glirulus在形态上相似,但Glirulus的上颊齿的三角座均为宽U型,具有完整的内脊,前中央脊通常与内脊相交,横脊唇端通常不游离。新属与Vasseuromys属的最主要形态差异在于上颊齿具有很发育的前边附脊和后边附脊,而后者上颊齿的前边附脊和后边附脊通常缺失或很不发育。归入该属的种还有土耳其早中新世的Vasseuromys duplex和Vasseuromys aff.V.duplex。土耳其Thrace早渐新世的Glis guerbuezi很可能是Gliruloides和Glirulus的共同祖先类型。Gliruloides可能生活于温湿的生态环境。     

The chemical composition of the meat of fat dormice (<Emphasis Type="Italic">Glis glis</Emphasis> L.)

The fat dormouse (Glis glis) is a traditional game species in the Republic of Croatia. Although today the fat dormouse is not frequently caught as game, it is still a source of animal protein in human nutrition in certain rural areas of Croatia. In this paper the chemical analysis of fat dormouse meat is presented. The average values for the quantity of water, fat, protein and ash in dormouse meat are comparable with the chemical composition of the meat of rabbits and brown hares, except for the important fact that rabbit and hare meat contains a greater quantity of fat on average. According to our results, the meat of fat dormice can be categorised as dietary food, characterised by a small percentage of fat (mean 2.83%) and a high amount of protein (mean 21.01%).     

Seasonal changes in the chemical composition of red deer (Cervus elaphus) semen

During reproductive quiescence, apart from a rapid decrease in total protein content, there was a 2–3 fold decrease in the activity of certain enzymes (glutamic-oxaloacetic transaminase (GOT), alkaline phosphatase, acrosin inhibitors) in the seminal plasma of red deer stags. The activity of the enzymes of the spermatozoa, hyaluronidase and acrosin, increased in the seminal plasma, probably due either to ageing of the spermatozoa, accumulated in the epididymis, or to changes in the permeability of cell membranes.These phenomena were accompanied by an increased concentration of albumins originating in blood, and by a noticeable disappearance of globulin fractions. This would point to a change in the permeability of the tissue barriers in the deer stag reproductive system, and to a decreased rate of protein synthesis in particular sections of this system, especially in the epididymis, during reproductive quiescence.     

达乌尔黄鼠冬眠期间体温的变化和冬眠模式

用植入式半导体温度记录元件iButton 记录了达乌尔黄鼠冬眠季节及其前后的体温,分析了其冬眠模式和体温调节特点。结果显示:1)实验室条件下,达乌尔黄鼠冬眠季节长短的个体差异较大,可以分成深冬眠型、
少冬眠型和不冬眠型三种类型;2)达乌尔黄鼠在冬季表现出深冬眠阵(最低体温Tbm in <20℃ ,冬眠阵的持续时间BD >24 h)、短冬眠阵(T_bmin < 20℃ , BD≤24h)和日眠阵(T_bmin ≥20℃ , BD≤24 h)3 种类型,最低体温分别
为2.54℃ ± 0.35℃ 、10.05℃ ± 1.97℃ 和23.09℃ ± 0.40℃ ,彼此之间差异显著。日眠阵阵间产热阶段的最高体温为38.09℃ ±0.17℃ ,高于深冬眠阵(37.31℃ ±0.15℃ )和短冬眠阵(37.22℃ ±0.31℃ ); 3)深冬眠阵和日
眠阵中最低体温均与环境温度显著相关,冬眠过程中的最低体温为-2.43℃ ;4)深冬眠过程中,多数个体可以短时(≤3 h)耐受- 2℃ ～ 0℃ 的低温,激醒或继续维持深冬眠,无致死效应,但长时间(15 h)或过度低温
(- 5℃ 以下)的条件下,深冬眠的达乌尔黄鼠被激醒(70% )或死亡(30% ),不能持续冬眠; 5)入眠前10 d体温日波动幅度显著增加,高于出眠后的日体温波动,且多数个体入眠前出现体温的“试降”。表明,冬眠前
入眠的准备阶段,动物的体温调节已开始发生变化;冬季日眠的调节机制可能与冬眠不同;短时- 2℃ ～ 0℃ 的体温对深冬眠的达乌尔黄鼠无致死效应。     

Evidence for the involvement of GD3 ganglioside in autophagosome formation and maturation

Sphingolipids are structural lipid components of cell membranes, including membrane of organelles, such as mitochondria or endoplasmic reticulum, playing a role in signal transduction as well as in the transport and intermixing of cell membranes. Sphingolipid microdomains, also called lipid rafts, participate in several metabolic and catabolic cell processes, including apoptosis. However, the defined role of lipid rafts in the autophagic flux is still unknown. In the present study we analyzed the role of gangliosides, a class of sphingolipids, in autolysosome morphogenesis in human and murine primary fibroblasts by means of biochemical and analytical cytology methods. Upon induction of autophagy, by using amino acid deprivation as well as tunicamycin, we found that GD3 ganglioside, considered as a paradigmatic raft constituent, actively contributed to the biogenesis and maturation of autophagic vacuoles. In particular, fluorescence resonance energy transfer (FRET) and coimmunoprecipitation analyses revealed that this ganglioside interacts with phosphatidylinositol 3-phosphate and can be detected in immature autophagosomes in association with LC3-II as well as in autolysosomes associated with LAMP1. Hence, it appears as a structural component of autophagic flux. Accordingly, we found that autophagy was significantly impaired by knocking down ST8SIA1/GD3 synthase (ST8 α-N-acetyl-neuraminide α-2,8-sialyltransferase 1) or by altering sphingolipid metabolism with fumonisin B1. Interestingly, exogenous administration of GD3 ganglioside was capable of reactivating the autophagic process inhibited by fumonisin B1. Altogether, these results suggest that gangliosides, via their molecular interaction with autophagy-associated molecules, could be recruited to autophagosome and contribute to morphogenic remodeling, e.g., to changes of membrane curvature and fluidity, finally leading to mature autolysosome formation.     

Evidence for the involvement of GD3 ganglioside in autophagosome formation and maturation

Sphingolipids are structural lipid components of cell membranes, including membrane of organelles, such as mitochondria or endoplasmic reticulum, playing a role in signal transduction as well as in the transport and intermixing of cell membranes. Sphingolipid microdomains, also called lipid rafts, participate in several metabolic and catabolic cell processes, including apoptosis. However, the defined role of lipid rafts in the autophagic flux is still unknown. In the present study we analyzed the role of gangliosides, a class of sphingolipids, in autolysosome morphogenesis in human and murine primary fibroblasts by means of biochemical and analytical cytology methods. Upon induction of autophagy, by using amino acid deprivation as well as tunicamycin, we found that GD3 ganglioside, considered as a paradigmatic raft constituent, actively contributed to the biogenesis and maturation of autophagic vacuoles. In particular, fluorescence resonance energy transfer (FRET) and coimmunoprecipitation analyses revealed that this ganglioside interacts with phosphatidylinositol 3-phosphate and can be detected in immature autophagosomes in association with LC3-II as well as in autolysosomes associated with LAMP1. Hence, it appears as a structural component of autophagic flux. Accordingly, we found that autophagy was significantly impaired by knocking down ST8SIA1/GD3 synthase (ST8 α-N-acetyl-neuraminide α-2,8-sialyltransferase 1) or by altering sphingolipid metabolism with fumonisin B1. Interestingly, exogenous administration of GD3 ganglioside was capable of reactivating the autophagic process inhibited by fumonisin B1. Altogether, these results suggest that gangliosides, via their molecular interaction with autophagy-associated molecules, could be recruited to autophagosome and contribute to morphogenic remodeling, e.g., to changes of membrane curvature and fluidity, finally leading to mature autolysosome formation.     

Glis vallesiensis n. sp., nouveau gliride (Rodentia,Mammalia) du Neogene de Seu d'Urgell (Catalogne,Espagne)

It is described Glis vallensiensis n. sp., which is characterized by its great size, similar to that of the present species Glis glis. It differs of the G. minor-G. sackdillingensis lineage in size and minor features. Glis vallesiensis belongs to the same lineage that Glis sp., from the Upper Miocene beds of Opole (1).     

Experimental ecology and hibernation of Onchidium struma (Gastropoda: Pulmonata: Systellommatophora)

This study investigated both laboratory-reared and pond-cultured subjects to explore the habit and hibernation patterns of the sea slug Onchidium struma (Mollusca, Gastropoda, Systellommatophora, Onchidioidea, Onchidiidae) from Shanghai and Zhejiang in China. Movement and feeding habits and the process of hibernation were observed in culturing tanks from June 2004 to March 2008. Our results showed that the conditions of movement are as follows: a minimum air temperature of 12 °C; a maximum light intensity of 25 lux and a minimum relative air humidity of 72%. Major movement is usually at dusk and during the night, and the average temperatures for fasting and beginning hibernation are 13.8 °C and 11.4 °C respectively. The analysis showed that the temperature is an essential factor affecting movement and feeding of O. struma and that RH and light intensity also play an important role, but are not necessarily required at the same time. In this study, the survival rate of O. struma through hibernation in high-biodiversity culturing tanks is 77.57% ± 2.86%.     

Energy use and management of energy reserves in hatchling turtles (Chrysemys picta) exposed to variable winter conditions

The painted turtle (Chrysemys picta) is an especially useful organism in the study of metabolic regulation during dormancy because it is sustained by finite energy reserves from hatching until emerging from its nest, about nine months later. In this study we subjected overwintering C. picta hatchlings to 4, 10, or 15 °C, temperatures simulating cold, mild, and warm winters, respectively, to investigate how various energy reserves are impacted by differential metabolic demands. An energy budget based on seasonal changes in caloric content showed that these turtles consumed an average of 0.39, 0.75, or 1.21 kJ g⁻¹, respectively, during the 6-month period of simulated hibernation. These estimates of energy use agreed reasonably well with estimates based solely on respirometric data. Unexpectedly, turtles in autumn contained little residual yolk, none of which was consumed by turtles in the cold- and mild-winter groups, this finding contradicting the widely held belief that residual yolk plays an important, direct role in the survival of turtles that overwinter inside their natal nest. By contrast, a marked reduction in dry mass of both liver and carcass attested to their importance in fueling metabolism and, indeed, catabolism of substrates from these components accounted for 31–52 and 35–63%, respectively, of the energetic cost of overwintering. The greater dependence on carcass reserves and relatively poor physiological condition of turtles in the mild- and warm-winter groups implies that metabolic demands imposed by high environmental temperatures would likely constrain post-emergence fitness.     

Characterization of nuclear gangliosides in rat brain: concentration, composition, and developmental changes

Nuclear gangliosides were characterized using two distinct fractions of large (N1) and small (N2) nuclear populations from rat brain. The ganglioside concentration of N1 nuclei from adult rat brain was 0.92 microg sialic acid/mg protein, which was about 3.8 times higher than that of N2 nuclei. N1 and N2 nuclear gangliosides showed similar compositional profiles; they contained major gangliosides of GM1, GD1a, GD1b, and GT1b, with GM3 in lesser amounts. c-Series gangliosides such as GT3, GQ1c, and GP1c were also detected in both nuclear preparations. Nuclear localization of gangliosides was confirmed by immunofluorescence with anti-GM1 antibody, cholera toxin B subunit, and c-series ganglioside-specific monoclonal antibody A2B5. Developmental changes of nuclear gangliosides were examined using rats of different ages ranging from embryonic day 14 (E14) to postnatal 7 weeks. The concentration of N1 nuclear gangliosides changed only slightly during development and did not correlate with that of whole-brain gangliosides. The developmental pattern of ganglioside composition of N1 nuclei was also distinguished from that of microsomal membranes; the ganglioside changes in N1 nuclei included reduced expression of di- and polysialogangliosides at E16 and higher proportions of GM3 at early and late stages of the period. These findings suggest that gangliosides in nuclear membranes are developmentally regulated in a distinct manner in brain cells.     

Ethanol-induced changes in the membrane lipid composition of Clostridium thermocellum

When ethanol is added to the growth medium of Clostridium thermocellum ATCC 27405 and C9, a different membrane composition is observed after the period of growth arrest. Changes in fatty acid composition and some unsaturated, branched hydrocarbons have been monitored by GLC-MS. There is a marked increase in normal and anteiso-branched fatty acids at the expense of isobranched fatty acids and an increase in short and unsaturated fatty acids. Thus, an adaptive response to growth in the presence of ethanol induces a membrane containing fatty acids with lower melting points and produces a more ‘fluid’ membrane. The suggestion is made that these membrane changes may be maladaptive to the performance of C. thermocellum.     

Changes in composition of harvested mushrooms (Agaricus bisporus)

Post-harvest changes in the biochemical composition of the mushroom were studied. Non-structural polysaccharide was found at levels greater than 10% dry wt in the fresh mushroom. After 4 days storage, the level had decreased to below 5% dry weight. The polysaccharide appeared to contain only glucose residues joined by α-1,4 and α-1,6 linkages. The chitin content of cell walls increased by ca 50% during 4 days storage, while cell wall glucan decreased. There was a large increase in urea content.     

The optimal depot fat composition for hibernation by golden-mantled ground squirrels (Spermophilus lateralis)

Golden-mantled ground squirrels (Spermophilus lateralis) are herbivores that hibernate during winter. Although little is known about the nutritional/physiological constraints on hibernation, numerous studies have demonstrated that increasing the amount of linoleic acid (a polyunsaturated fatty acid) in the diet enhances hibernation. This is probably because high linoleic acid diets reduce the melting points of the depot fats produced for hibernation which makes them more metabolizable at low body temperatures. This suggests that a major limitation on hibernation may be obtaining enough linoleic acid in the diet for proper hibernation. In all previous studies, however, the amount of linoleic acid in the diets of free-ranging animals was either not considered, or the range of dietary linoleic acid contents in the experiments was less than that of natural diets. It is thus not known whether the amount of linoleic acid available to hibernators under natural conditions actually limits their torpor patterns. A series of laboratory feeding and hibernation experiments were conducted with S. lateralis and artificial diets with different linoleic acid contents that were either below or above the linoleic acid content of the natural diet. The results demonstrated that when dietary linoleic acid contents are either below or above natural levels, hibernation ability is greatly reduced. Hibernation ability was reduced when the squirrels were maintained on a high linoleic acid diet probably by the production of toxic lipid peroxides in brown adipose tissues. The results indicate that there is an optimal level of dietary linoleic acid for proper hibernation, and this is equal to that of the natural diet. The amount of linoleic acid available in the diet thus does not limit hibernation under normal natural conditions.Abbreviations BAT brown adipose tissue - bm body mass - FA fatty acid - PUFA polyunsaturated fatty acid - T _a ambient temperature - T _b body temperature - WAT white adipose tissue     

Ganglioside composition changes in spongiform encephalopathies: Analyses of 263K scrapie-infected hamster brains

Ganglioside composition in brains of terminally ill LVG/LAK golden Syrian hamsters infected with the 263K strain of the scrapie agent was analyzed. Results were compared to those obtained from noninfected animals matched by age, sex, and strain. Gangliosides extracted from scrapie-infected animals showed little change in major components, while an increased number of new alkali-labile species appeared. Additionally, the animal strain employed demonstrated a significant polymorphism in brain ganglioside composition. No significant changes in incubation time, clinical development or pathologic features of scrapie were associated with this polymorphism.     

Structure of the main ganglioside from the brain of Xenopus laevis

The main component of the ganglioside¹ mixture from the brain of the adult amphibian Xenopus laevis accounts for 35% of the total, as lipid bound sialic acid. This ganglioside has been purified and characterized by thin layer chromatography, partial and exhaustive enzymatic hydrolysis with sialidase, TLC-overlay procedures with anti-Gg₄Cer and anti-Neu5Ac6GalNAc specific monoclonal antibodies and mass spectrometry. All together the results suggest the following structure:Neu5Ac8Neu5Ac3Gal3(Neu5Ac8Neu5Ac6)GalNAc4Gal4Glc1Ceror, IV³--Neu5Ac₂,III⁶--Neu5Ac₂-Gg₄Cer.