Juvenile survival curves in a solitary ground squirrel with a prolonged hibernation:effects of individual characteristics,environment,and maternal investment

Juvenile survival is a key life-history influence on population dynamics and adaptive evolution.We analyzed the effects of individual chara-cteristics,early environment,and maternal investment on juvenile survival in a large solitary hibernating rodent-yellow ground squirrel Spermophilus fulvus using Cox mixed-effects models.Only 48%of weaned pups survived to dispersal and 17%survived to hibernation.Early life expectancy was primarily determined by individual characteristics and,to a lesser extent,by the early environment.The strongest and pos-itive predictor of juvenile survival was body mass which crucially affected mortality immediately after weaning.Males suffered higher mortality than females after the onset of dispersal;however,the overall difference between sexes was partly masked by high rates of mortality in the first days after emergence in both sexes.Later emerged juveniles had lower life expectancy than the earliest pups.The overall effect of local juvenile density was positive.Prolonged lactation did not enhance juvenile survival:Pups nursed longer survived shorter than the young nursed for a shorter period.Our findings support the hypothesis that females of S.fulvus cannot effectively regulate maternal expenditures to mitigate the effects of unfavorable conditions on their offspring.The strategy to deal with seasonal time constraints on life history in female S.fulvus suggests an early termination of maternal care at the cost of juvenile quality and survival.This female reproductive strategy corresponds to a"fast-solitary"life of folivorous desert-dwelling S.fulvus and other solitary ground squirrels with prolonged hibernation.

Expression Profiling and Structural Characterization of Micro RNAs in Adipose Tissues of Hibernating Ground Squirrels

Micro RNAs（mi RNAs） are small non-coding RNAs that are important in regulating metabolic stress. In this study, we determined the expression and structural characteristics of 20 mi RNAs in brown（BAT） and white adipose tissue（WAT） during torpor in thirteen-lined ground squirrels. Using a modified stem-loop technique, we found that during torpor, expression of six mi RNAs including let-7a, let-7b, mi R-107, mi R-150, mi R-222 and mi R-31 was significantly downregulated in WAT（P 〈 0.05）, which was 16%–54% of euthermic non-torpid control squirrels,whereas expression of three mi RNAs including mi R-143, mi R-200 a and mi R-519 d was found to be upregulated by 1.32–2.34-fold. Similarly, expression of more mi RNAs was downregulated in BAT during torpor. We detected reduced expression of 6 mi RNAs including mi R-103 a, mi R-107, mi R-125 b, mi R-21, mi R-221 and mi R-31（48%–70% of control）, while only expression of mi R-138 was significantly upregulated（2.91 ± 0.8-fold of the control, P 〈 0.05）. Interestingly,mi RNAs found to be downregulated in WAT during torpor were similar to those dysregulated in obese humans for increased adipogenesis, whereas mi RNAs with altered expression in BAT during torpor were linked to mitochondrial b-oxidation. mi RPath target prediction analysis showed that mi RNAs downregulated in both WAT and BAT were associated with the regulation of mitogen-activated protein kinase（MAPK） signaling, while the mi RNAs upregulated in WAT were linked to transforming growth factor b（TGFb） signaling. Compared to mouse sequences, no unique nucleotide substitutions within the stem-loop region were discovered for the associated pre-mi RNAs for the mi RNAs used in this study, suggesting no structure-influenced changes in pre-mi RNA processing efficiency in the squirrel. As well, the expression of mi RNA processingenzyme Dicer remained unchanged in both tissues during torpor. Overall, our findings suggest that changes of mi RNA expression in adipose tissues may be linked to distinct biological roles in WAT and BAT during hibernation and may involve the regulation of signaling cascades.

Frequency-modulated second elements of two-element alarm calls do not enhance discrimination of callers in three Eura- sian ground squirrels

Alarm calls of the European Spermophilus citellus （EGS）, Taurus S. taurensis （TGS） and Anatolian S. xanthoprymnus （AGS） ground squirrels share the same basic structure. They are tonal sounds consisting primarily of two different elements. The first element, often produced without the second element, has limited frequency modulation, while the second element is more frequency modulated. The present study examined whether this frequency-modulated element enhances the individual distinc- tiveness of calls, allowing calls to be ascribed with greater confidence to individual callers of the three species. Cross-validated discriminant function analysis （DFA） based on five acoustic parameters of the first element successfully classified calls to correct individuals （EGS： 90%, TGS： 98%, AGS： 96%）. Cross-validated DFA based on five acoustic parameters of the second element was also successful in classifications （EGS： 88%, TGS： 86%, AGS： 96%）, though discrimination of callers based on parameters of the second versus first element was the same for the AGS, lower for the EGS and significantly lower for the TGS. Cross-validated DFA based on five acoustic parameters of two-element calls also successfully classified calls to correct individu- als （EGS： 93%, TGS： 98%, AGS： 97%）, though did not improve the extent to which calls could be classified to individuals be- yond that based on the ftrst element alone. Thus, the second element does not enhance the individual distinctiveness of calls, but may convey other information such as the location of the caller [Current Zoology 58 （5）： 749-757, 2012].

The song remains the same： Juvenile Richardson＇s ground squirrels do not respond differentially to mother＇s or colony member＇s alarm calls

Alarm calls are emitted by Richardson＇s ground squirrels Urocitellus richardsonii in response to avian and terrestrial predators. Conspecifics detecting these calls respond with increased vigilance, promoting predator detection and evasion, but in doing so, lose time from foraging. That loss can be minimized if alarm call recipients discriminate among signalers, and weight their response accordingly. For juvenile ground squirrels, we predicted that the trade-off between foraging and vigilance could be optimized via selective response to alarm calls emitted by their own dam, and/or neighboring colony members over calls broad- cast by less familiar conspecifics. Alarm calls of adult female Richardson＇s ground squirrels were elicited in the field using a predator model and recorded on digital audio tape. Free-living focal juveniles were subjected to playbacks of a call of their mother, and on a separate occasion a call from either another adult female from their own colony, or an adult female from another colony. Neither immediate postural responses and escape behavior, nor the duration of vigilance manifested by juveniles differed with exposure to alarm calls of the three adult female signaler types. Thus, juveniles did not respond preferentially to alarm calls emitted by their mothers or colony members, likely reflecting the high cost of ignoring alarm signals where receivers have had limited opportunity to establish past signaler reliability [Current Zoology 58 （5）： 773-780, 2012].

Age of maturation and behavioral tactics in male yellow ground squirrel Spermophilus fulvus during mating season

Life-history theory predicts that in hibemators age of maturation is related positively to body size and negatively to the duration of active season aboveground. Yellow souslik is a large-sized ground squirrel with long hibernation, which suggests late maturation. We used four-year field observations of marked individuals to determine the age of maturation in males through analysis of age-dependent variation in body size, mass, androgen status, timing of spring emergence, ranging patterns and social behavior during the mating season. Yearling males were smaller, lighter, had lower level of fecal testosterone, emerged later and had smaller home ranges than older males. Social activity and the number of females encountered did not differ between age classes. After the second hibernation none of the studied parameters varied with age. Cluster analysis revealed two behavioral tactics： ＂active＂ males （adults only） emerged earlier, ranged more widely, initiated more contacts, encountered more females and were heavier than ＂passive＂ males （both yearling and adult）. Thus, males of S. fulvus reached adult size and matured after two hibernations, which is relatively fast for such a big species with short active period. Indirect evidence for copulations and high variation among yearlings in all parameters suggest that some of them might successfully compete with adults. Active tactic of wandering and searching for females is energetically costly, and probably only adult males in good physical condition can afford it, whereas passive tactic of residing is energy saving and good for adults in poor condition and for yearlings that are continuing to grow.

Burrowing Richardson's ground squirrels affect plant seedling assemblages via environmental but not seed bank changes

In grassland ecosystems,burrowing mammals create disturbances,providing habitat for animal species and increasing plant community diversity.We investigated whether seedling assemblages on Richardson's ground squirrel Urocitellus richardsonii mounds result from seed rearrangement or environmental changes that favor germination of certain species over others.To test whether ground squirrels rearrange the seed bank by burrowing,we compared seed compositions among mounds,burrows,and undisturbed soil.To test whether ground squirrels change environmental conditions,we compared soil nitrate and bare ground cover on and off mounds.We also compared seedlings that germinated on mounds with seedlings that germinated on artificial disturbances from which we removed aboveground vegetation.Soil nitrate and bare ground cover were significantly higher on mounds than artificial disturbances.While seed richness and abundance did not differ among mounds,burrows,and undisturbed soil,seedling richness was reduced on mounds relative to artificial disturbances.Burrowing disturbance favors seedlings that can capitalize on bare ground availability but are less able to immobilize nitrate,as opposed to perennial species that immobilize more nitrate but take longer to establish.Our results suggest that Richardson's ground squirrels act as ecosystem engineers,although future research following succession on ground squirrel mounds is necessary to understand how they influence plant communities past the seedling stage.

Validation of a radioimmunoassay-based fecal corticosteroid assay for Richardson＇s ground squirrels Urocitellus richardsonii and behavioural correlates of stress

We validated a radioimmunoassay-based method quantifying fecal glucocorticoid metabolites （FGMs） from captive male and female Richardson＇s ground squirrels Urocitellus richardsonii. Blood samples were drawn to explore the correlation between plasma cortisol and FGM concentrations. We also injected groups of squirrels with normal saline （CTL; control）, adre- nocorticotropic hormone （ACTH; stimulating adrenal activity）, or dexamethasone （DEX; suppressing adrenal activity）. Potential correlations between stress and behaviour were explored through quantification of fecal pellet production and the intervention necessary to elicit defecation, as well as the behaviour of subjects in the context of handling. Changes in plasma cortisol concen- tration between capture （baseline）, and following handling （stress-induced） were also quantified for free-living squirrels. While glucocorticoid concentrations recovered from feces during our captive-animal study were not well correlated with plasma eortisol concentrations, and uncorrelated with defecation or behaviour, FGM concentrations did reflect the activation of the hypothalamic- pituitary-adrenal （HPA） axis. FGM concentrations increased significantly during initial captivity, but declined to baseline level as individuals acclimated to the novel environment. Injection of subjects with ACTH increased FGMs above baseline, confirming activation of the HPA axis. Plasma cortisol concentrations increased significantly with induced stress, indicating that capture and handling activated the glucocorticoid stress response even among previously handled, free-living subjects. Our findings validate a non-invasive tool that will afford new insight into the physiological processes underlying social, reproductive and antipredator behaviour of Richardson＇s ground squirrels [Current Zoology 60 （5）： 591-601, 2014 ].

Like mother, like daughter： heritability of female Richardson＇s ground squirrel Urocitellus richardsonii cortisol stress responses

Activation of the hypothalamic-pituitary-adrenal （HPA） axis liberates glucocorticoids, which provides an acute indication of an individual＇s response to stressors. The heritability of the stress response in wild mammals, however, remains poorly documented. We quantified the cortisol stress response of female Richardson＇s ground squirrels （RGSs） to handling and physical restraint, testing for： （1） the effects of individual age, time of day, and sample latency; （2） repeatability within individuals; （3） narrow-sense heritability; and （4） differences among individuals owing to potential genetic and/or environmental effects. We detected a positive linear relationship between baseline plasma cortisol （BL-cortisol） concentration and stress-induced plasma cortisol （Sl-cortisol） concentration that defined each individual＇s cortisol stress response. BL-cortisol, SI-cortisol, and stress response did not differ according to the time the sample was taken, or by subject age. Cortisol stress response was highly repeatable within individuals, had a mother-offspring heritability of h2 =0.40 ± 0.24 （mean ±SE）, full-sibling heritability of h2s = 0.37 ± 0.71, and half-sibling heritabil- ity of hHS^2 = 0.75 ± 1.41. Stress responses of sibling groups, immediate-family groups, and squir- rels within a given area did not differ, whereas those of individuals from more distantly related matrilines did. Our results highlight the natural variability in HPA axis reactivity among individuals by quantifying both BL- and SI-cortisol levels, demonstrate partial heritability of the stress response that is not attributable to environmental variation, and suggest that at least part of an indi- vidual＇s stress response can be accounted for by differences in matrilineal history.

Seasonal change of circulating leptin associated with testicular activities of the wild ground squirrels(Citellus dauricus)

The purpose of this study was to explore the variations in the circulating leptin concentrations of the wild ground squirrels in relation to seasonal changes in testicular activities.Hematoxylin-eosin staining showed all types of elongated spermatids and spermatogenic cells existed in the testis in April,while the primary spermatocytes and spermatogonia were most advanced stages of germ cells in June.In addition,the primary spermatocytes,secondary spermatocytes,and spermatogonia were most advanced stages of germ cells in September.The highest circulating leptin concentration was consistent with the maximum body weight results from accumulation of adipose tissue in September.The mRNA expression level of leptin receptor(Ob-R)and STAT3 was lowest in June,raised in September,and remained increased in April.Ob-R and STAT3 were stronger staining in the Leydig cells in July.Moreover,the concentrations of testosterone(T)showed the maximum values in April,the minimum values in June,and significant increases in September.Furthermore,it is worth noting that the levels of T increased with the mRNA levels of Ob-R,STAT3,StAR,and testicular steroidogenic enzymes(3β-HSD,P450c17,and P450scc).Moreover,RNA-seq analyses of testis during the different periods showed that a total of 4209 genes were differ-entially expressed genes(DEGs);further analysis revealed that DEGs related with the Jak/STAT pathways and reproduction were altered.Taken together,the results suggested that the leptin regulated testicular function through the Jak/STAT pathways and testicular steroidogenic factor expressions.

达乌尔黄鼠季节性肥胖与胰腺功能稳态

储脂类冬眠动物在入眠前的育肥阶段大量积累体脂作为越冬的重要能源物质。达乌尔黄鼠(Spermophilus dauricus)在短短2~3个月的育肥期间体质量增加近1倍,然而该物种快速育肥过程是否引起糖脂代谢的紊乱以及类似于人类肥胖相关的代谢异常尚不清楚。在本研究中,我们检测了育肥不同阶段黄鼠血糖含量、糖耐受情况、血清和非脂肪类器官中甘油三酯和游离脂肪酸含量以及血清中胰岛素和胰高血糖素含量。结果显示,达乌尔黄鼠在育肥期间血糖保持稳定,心脏、肝脏及肾脏等非脂肪类器官中甘油三酯和游离脂肪酸含量无显著性变化。血清中甘油三酯及胰岛素含量无显著性差异,但游离脂肪酸含量显著升高,胰高血糖素含量显著下降。这些结果说明,达乌尔黄鼠在育肥期间并没有产生高血糖、高血脂、脂质异位堆积和胰岛素抵抗等症状。育肥期间胰高血糖素的降低或许是维持其血糖稳定的机制之一。此外,在冬眠之前,黄鼠胰岛面积以及胰岛细胞数目呈现增加趋势,提示育肥期间可能存在胰岛细胞新生,这可能与育肥期间胰岛功能维持有关。达乌尔黄鼠作为储脂类的冬眠动物,具有独特的体脂积累机制,或将为肥胖引起的代谢综合征的治疗提供借鉴。

益口槟葛对金黄地鼠健康的影响研究

目的:研究连续嚼食基于葛根制备的槟榔风味咀嚼块益口槟葛4周对金黄地鼠的健康影响,评估益口槟葛的嚼食安全性。方法:将40只金黄地鼠随机分为4组,分别为空白对照组、葛根组、益口槟葛组和槟榔组,每组10只。空白组金黄地鼠用10%水合氯醛以3mL/kg剂量进行麻醉,以保证各组处理条件一致,其他实验组金黄地鼠在麻醉后将葛根、槟葛或槟榔(均切碎呈小颗粒状)塞至两颊,每2天1次,共持续给药4周。每两周用游标卡尺测金黄地鼠口腔开合度;第4周对各组金黄地鼠进行高架十字迷宫实验,评估葛根、益口槟葛和槟榔对金黄地鼠行为能力的影响;饲喂嚼食4周后,处死各组金黄地鼠,检测各主要脏器指数、肝转氨酶活性,评估其生理健康状况;取颊囊组织进行染色,并提取RNA,检测与口腔黏膜下纤维化有关的关键基因表达情况。结果:饲喂4周后,各实验组地鼠摄食量及体质量出现明显下降。槟榔组转氨酶显著升高,肾指数各组间无明显差异。各组地鼠颊囊无明显外观改变,开口度无明显差异,组织染色结果显示各咀嚼组出现一定的黏膜组织改变,槟榔组出现更明显的炎性细胞浸润。mRNA水平上的纤维化相关基因差异表达提示,槟榔咀嚼组出现一定的口腔黏膜下纤维化征兆,益口槟葛组尚不明显。此外,高台十字迷宫实验结果表明,嚼食益口槟葛后,金黄地鼠活动兴奋性显著提高,表现出强烈的探索意识。结论:持续4周嚼食益口槟葛对金黄地鼠的健康无明显影响,未见对口腔的损伤,同时具有较好的神经兴奋作用。

达乌尔黄鼠的资源利用及模式动物化研究进展

达乌尔黄鼠(Spermophilus dauricus)是我国研究冬眠的主要动物模型,具有适应极端低体温、低代谢以及抗缺血-再灌注损伤、抗废用性肌萎缩等生理特点,并且具有独特的体脂积累和耐受机制。这些生理特征在临床及航天领域的应用中具有重要借鉴意义和研究价值。达乌尔黄鼠的模式动物化有助于对上述生理机制进行深入探究。本文综述了达乌尔黄鼠的生物学特征及其在临床与航天应用的研究价值,介绍了目前国内达乌尔黄鼠在实验室和野外的繁殖和实验动物化的进展,展望了将该物种模式动物化的前景及其关注点。

6kV浆液循环泵电机定子绕组接地故障分析及预控

某600 MW火电机组6 kV脱硫浆液循环泵电机在机组降负荷后短时升负荷时,带载热态启动过程中出现速断保护动作现象,测量电机绝缘电阻为零,更换备用电机运行。通过对电机解体,发现转子鼠笼端环焊块脱落、定子绕组外绝缘破损严重,确定绕组接地造成保护跳闸,从保护定值、运行操作、规程要求、检修维护多方面分析根本原因,提出工作票及运行规程优化建议,为预控此类故障提供参考思路。

达乌尔黄鼠冬眠模式年龄性别差异的实验研究

野外环境中达乌尔黄鼠冬眠的模式存在年龄性别的差异,为研究这种差异是否与冬季可利用的能量有关,我们将动物按年龄和性别分为成年雄性、成年雌性、亚成年雄性和亚成年雌性4组,在实验室条件下监测冬眠前能量贮存和冬眠季节冬眠模式和体重的变化。结果表明:达乌尔黄鼠的入眠和出眠时间基本为先雄性后雌性,先成年后亚成年;成年黄鼠冬眠季节的持续时间和深冬眠的累计时间短于亚成年组,与野外的研究基本一致。代表能量贮存量的最大体重值为成年大于亚成年,雄性大于雌性;最大体重出现时间也是先雄性后雌性,先成年后亚成年,这与冬眠模式的年龄性别差异相一致。达乌尔黄鼠冬眠模式的年龄性别差异本质上可能受体内能量的贮存状况的影响,黄鼠能够利用可利用的能量减少冬眠表达。

达乌尔黄鼠冷暴露、冬眠及激醒时的外周甲状腺激素水平变化

探讨了达乌尔黄鼠在冷暴露、冬眠及激醒时的外周甲状腺激素水平变化和激素代谢。达乌尔黄鼠在非冬眠季节 ( 7～ 8月 )冷暴露 ( 4℃± 2℃ ) 1天 ,导致血清T3和T4浓度迅速增加 ,T3/T4不变 ;经 4周冷驯化后 ,T3维持在高水平上 ,T4降低 ,T3/T4增加 ,外周组织中的T4脱碘酶活性升高。表明冬眠动物与非冬眠动物的甲状腺机能及其激素代谢的冷适应性调节一致。在冬眠季 ( 12～ 1月 )的冬眠和激醒过程中 ,外周组织的T4脱碘酶活性、血清T3和T4水平比常温达乌尔黄鼠的高 ,显著高于夏季的水平 ,T3/T4不变。表明达乌尔黄鼠甲状腺机能及其激素水平存在季节性变化。

阿拉善黄鼠模式产地标本染色体核型

采用骨髓细胞直接制备染色体的方法,对采自阿拉善黄鼠(Spermophilus alaschanicus Buchner,1888)模式标本产地,内蒙古阿拉善南部典型荒漠区的5号黄鼠(Spermophilus spp.)标本进行染色体研究。结果表明,该种二倍体体细胞的染色体数为2n=38,与达乌尔黄鼠(草原黄鼠)(S.dauricus Brandt,1843)二倍体体细胞的染色体数2n=36,完全不同,且形态特征与达乌尔黄鼠具有明显差异。基于该种的染色体和形态特征以及分布区域,并与国内外相关研究比较的结果,确认该种为阿拉善黄鼠。

脑室注射6-羟多巴胺对黄鼠冬眠入眠的影响

采用脑室内注射化学去交感药物6-羟多巴胺(6-OHDA)的方法,观察了人为地降低脑内去甲肾上腺素(NE)系统活动对达乌尔黄鼠入眠的影响。结果表明:脑室注射100-200μg6-OHDA使脑内NE含量减少50％以上,明显促进黄鼠入眠,平均入眠诱导期比自然冬眠动物明显缩短,整个冬眠季内冬眠时间延长,冬眠黄鼠仍具有正常的入眠觉醒周期。这些结果提示脑内NE系统活动水平降低是触发动物入眠的重要因素之一。

达乌尔黄鼠冬眠期与非冬眠期的产热活性及激素调节

测定了达乌尔黄鼠 (SpermophilusDauricus)冬季冬眠时和秋季非冬眠时的产热活性及其激素调节 .达乌尔黄鼠下丘脑促甲状腺激素释放激素 (TRH)冬眠时含量显著高于非冬眠时的 ,血清中三碘甲腺原氨酸 (T3)、甲状腺素 (T4 )质量浓度也有明显增加 .表明达乌尔黄鼠下丘脑甲状腺轴激素水平和功能存在季节性变化 ,冬眠时该轴是激活的 ,这个轴的激活 ,有利于黄鼠冬眠觉醒中褐色脂肪组织 (BAT)的产热 .冬眠时达乌尔黄鼠下丘脑促肾上腺激素释放激素 (CRF)的质量分数、肾上腺皮质酮的质量分数和肾上腺质量明显比非冬眠季节的个体低 .表明达乌尔黄鼠在冬眠过程中 ,下丘脑CRF 肾上腺轴受到抑制 ,从而解除了对BAT产热的抑制作用 .

达乌尔黄鼠(Spermophilus dauricus)生态学研究进展

达乌尔黄鼠(Spermophilus dauricus)是广泛分布于中国的主要啮齿类物种,栖息于森林、草原和农田耕地等各类生境中,具有个体小、数量多、适应性强、分布广等特征,携带鼠疫杆菌,对农、林、牧业危害和人类卫生健康影响较大。综述了其生态学和实验动物化开发与防控等方面的研究概况及其进展,展望了可能的研究方向和存有的问题。旨在为该物种的有效监测、综合控制和管理与开发利用等提供参考。

尾部悬吊对达乌尔黄鼠比目鱼肌形态及mATP酶活性的影响

采用尾部悬吊法建立后肢骨骼肌废用的动物模型,以肌球蛋白ATP酶(mATPase)法测定比目鱼肌的mATPase活性,依据mATPase染色结果进行肌纤维分型,并测量肌纤维横截面积(Cross-section area,CSA),首次观察了尾部悬吊对达乌尔黄鼠比目鱼肌湿重、CSA和梭外肌、梭内肌纤维mATPase活性的影响,并与尾部悬吊大鼠进行了比较。旨在探讨冬眠动物骨骼肌在废用状态下的变化。结果显示,尾部悬吊14d可使大鼠比目鱼肌湿重体重比下降35.52%(P<0.001),Ⅰ型肌纤维CSA和Ⅱ型肌纤维CSA分别下降18.91%和20.68%(P<0.05);肌纤维平均CSA减少20.45%(P<0.01)。比目鱼肌中Ⅰ型肌纤维的构成比由对照组的80.61%降低为66.83%,Ⅱ型肌纤维的构成比由19.39%增加到33.17%(P<0.001);梭内肌纤维mATPase活性增强,核袋1纤维的mATPase染色由阴性(-)转变为强阳性(+++),核袋2纤维和核链纤维由阳性(++)转变为强阳性(+++)。而达乌尔黄鼠在尾部悬吊14d后,比目鱼肌湿重仅比对照组下降0.05%,Ⅰ、Ⅱ型肌纤维CSA与平均CSA分别比对照组减少0.84%、0.63%和0.37%,均无明显差异(P>0.05);与对照组相比,比目鱼肌中Ⅰ型肌纤维的构成比从82.55%减少到77.30%,Ⅱ型肌纤维的构成比由17.45%增加到22.70%(P<0.05);梭内肌纤维mATPase活性亦明显升高,核袋1纤维的mATPase染色由对照组的阴性(-)转化为强阳性(+++),核袋2纤维及核链纤维则由对照组的阳性(++)转化为核袋2纤维呈阳性(++),核链纤维则呈弱阳性(+)。结果表明:尾部悬吊可致大鼠比目鱼肌明显萎缩;达乌尔黄鼠比目鱼肌则无明显萎缩;两者比目鱼肌梭内、外肌mATPase活性均明显升高。