内蒙古半荒漠区啮齿动物群落分类及其多样性研究

自1988～1993年在内蒙古半荒漠区约11万km2的调查区域内共设置259个样方,布放有效夹日131109个,捕获啮齿动物19种。在此基础上,用其捕获率作为分类量纲,以样方-种的捕获率组成259×19的原始数据矩阵,应用快速聚类法进行鼠类群落划分,根据分类结果,并结合调查区域内各种地带性植被的特点将该地区啮齿动物划分为9个不同的鼠类群落。即群落:戈壁五趾跳鼠 五趾跳鼠 长爪沙鼠群落,群落生境为半荒漠区内典型的高平原、丘陵荒漠草原;群落:三趾跳鼠 子午沙鼠 小毛足鼠群落,群落生境为沙地,主要分布于阴山北麓的覆沙地带;群落;草原黄鼠 五趾跳鼠 长爪鼠群落,群落生境为半荒漠区内平原丘陵典型草原和山地典型草原;群落:赤颊黄鼠 黑线毛足鼠 五趾跳鼠群落,群落生境为戈壁针茅-隐子草草原;群落:戈壁五趾跳鼠 三趾跳鼠 蒙古羽尾跳鼠群落,群落生境为草原化荒漠,主要以强旱生灌木和半灌木组成;群落:黑线仓鼠 长爪沙鼠 小毛足鼠群落,群落生境为人工草地及阴山北麓山顶种植荞麦和莜麦的农田;群落:小毛足鼠 三趾跳鼠 长爪沙鼠群落,群落生境为典型荒漠草原重度退化的短花针茅冷蒿草场;群落:长尾仓鼠 大林姬鼠 棕背群落,群落生境为阴山山脉中段的次生林地如五当召、大桦背及蛮汉山;群落:五趾跳鼠 草原黄鼠 黑线毛足鼠群落     

内蒙古库布齐沙地四种啮齿动物非颤拌性产热的季节变化

为了解非颤抖性产热在内陆荒漠小型哺乳动物适应性热能调节中的作用,1997年对库布齐荒漠沙地环境4种啮齿动物：三趾跳鼠（Dipus sagitta)、子午沙鼠（Meriones meridianus)、小毛足鼠（Phodopus roborovskii)和黑线仓鼠（Cricetulus barabensis)的非颤抖性产热季节变化进行了测定。4种动物的非颤抖性产热在秋季低温刺激下明显高于夏季,而且小毛足鼠和黑线仓鼠在秋季的最大非颤抖性产热分别高于春季14％和35％。典型荒漠种小毛足鼠的季节变化最明显,夏季最低。结果表明,生活在内陆干旱地区的动物生长期进化过程中,发展了良好的非颤抖性产热体温调节机制适应环境温度的季节变化。     

内蒙古典型草原布氏田鼠营养生态位及其种间关系

研究啮齿动物营养生态位不仅可以了解啮齿动物在生态系统中所占据的营养层,而且可以揭示啮齿动物不同生长发育时期的主要食物来源及变化,通过分析营养生态位的特征及变化,可以探讨多种啮齿动物的种间关系。本研究于2018年7月,在内蒙古典型草原采用铗日法捕获啮齿动物标本4种81只,应用稳定性¹³C、¹⁵N同位素技术对布氏田鼠（Lasiopodomys brandtii）营养生态位及其与达乌尔黄鼠（Spermophilus dauricus）、黑线毛足鼠（Phodopus sungorus）、五趾跳鼠（Allactaga sibirica）的种间关系进行研究。结果表明：（1）布氏田鼠不同年龄组骨骼组织营养生态位宽度即稳定同位素贝叶斯标准椭圆面积,Ⅲ龄组最高（0.802‰²）,Ⅱ龄组次之（0.699‰²）,Ⅳ龄组最低（0.666‰²）,3个年龄组之间营养生态位共同重叠面积为0.064‰²,其共同食物源仅占不到10%;（2）布氏田鼠无论是长期食性或短期食性,与另外3种均不存在食物源竞争,但布氏田鼠生态位宽度较窄对食物的选择性较强,因此一旦食物源成分改变不再适于该鼠,布氏田鼠种群极有可能面临食物源短缺,种群迁移可能是最直接的选择。     

甘肃鼢鼠种群动态及其影响因素的初步分析

啮齿动物种群动态及影响因素的研究是害鼠预测预报的基础。国内曾对大林姬鼠、子午沙鼠、大仓鼠、布氏田鼠、黑线仓鼠、小家鼠等种群动态及影响因素进行过研究。作者于１９９２～１９９４年,在延安树木园和富县牛武林场对甘肃鼢鼠种群动态及影响因素做了研究,现将结果报...     

年龄对布氏田鼠和长爪沙鼠能量代谢的影响

能量代谢对动物的存活和繁殖等生活史特征具有重要的调控作用.布氏田鼠(Lasiopodomys brandtii)和长爪沙鼠(Meriones unguiculatus)是内蒙古草原同域分布的两种啮齿动物,前者的体重和野外寿命要明显小于后者,这符合寿命随体型增大而增加的一般规律.本研究进一步探讨了随年龄增加,两种动物的能量代谢特征的改变.发现布氏田鼠的非颤抖性产热能力随年龄增加而降低,而长爪沙鼠的非颤抖性产热能力随年龄增加而保持稳定.布氏田鼠的摄食能力和身体脂肪储备随年龄增加而降低;而长爪沙鼠摄食能力不随年龄改变,脂肪储备则随年龄增加而增加.长爪沙鼠的基础代谢水平低于布氏田鼠,其繁殖成熟时间更长.本研究推测,这些随年龄而变的生理特征反映了两种动物不同的生活史对策:布氏田鼠更倾向于尽快繁殖,其他与生存相关的生理指标随年龄增加而迅速降低,而长爪沙鼠更倾向于将能量投资到较晚期的存活和繁殖.     

不同干扰下阿拉善荒漠啮齿动物优势种对气候变化的响应

气候变化已对物种分布范围和丰富度产生了极大的影响。荒漠生态系统对气候变化的反应可能更加敏感。作为荒漠生态系统的重要组成者,了解荒漠啮齿动物特别是优势鼠种将对气候变化如何响应,对于荒漠地区生物多样性的维持将具有重要意义。2002—2010年,采用标志重捕法对阿拉善荒漠4种不同生境下啮齿动物优势种群进行了研究,分别利用Spearman相关分析以及典范对应分析(Canonical Correspondence analysis,CCA)对啮齿动物优势种群动态与年平均温度和年降水量的相关性进行了分析。结果表明,不同啮齿动物优势种对温度和降雨的响应不同,尤其以子午沙鼠表现最为显著。跳鼠对温度的适宜性要高于仓鼠科的子午沙鼠和黑线仓鼠,而仓鼠科啮齿动物对降雨的适宜性高于跳鼠。较小尺度上的人为干扰更可能从改变食性和生境的途径上加剧或缓冲降雨对荒漠啮齿动物优势种的影响,而不是改变温度对啮齿动物的作用。     

七种实验动物对沙鼠利什曼原虫感受性的研究

本文报道3株近交系小鼠、沙鼠和仓鼠对沙鼠利什曼原虫的感受性。结果表明,BALB/c株小鼠,长爪沙鼠和黑线仓鼠对沙鼠利什曼有较好的感受性。CFW株小鼠感染后不久即可自愈,而C57 BL株鼠则抗拒感染。除了黑线仓鼠的睾丸在感染原虫后偶可产生转移性皮肤损害外,其余实验动物的感染均仅局限在接种部位的皮肤,进一步表明沙鼠利什曼是一种亲皮肤性的原虫。     

长爪沙鼠与黑线仓鼠的温度选择比较

本文使用自制的陆生动物温度选择仪,对长爪沙鼠和黑线仓鼠的温度选择进行了比较,结果表明,长爪沙鼠的选择温度(29.06±0.62℃)较黑线仓鼠(26.65±0.64℃)高。这种差异可能与两种鼠的栖息环境及昼夜节律的不同有关。     

应用马尔可夫链模型预测长爪沙鼠和黑线仓鼠种群数量

依据1984～2004年21年在呼和浩特郊区对长爪沙鼠(Meriones unguiculatus)和黑线仓鼠(Cricetulus barabansis)种群数量动态的调查数据,结合优选法(0.618法),应用加权马尔可夫链预测模型,建立了长爪沙鼠和黑线仓鼠种群数量预测模型。应用此模型分别预测了长爪沙鼠和黑线仓鼠2004年的种群数量,预测值与实测值相符,预测准确。同时,预测了未来三年(2005～2007年)长爪沙鼠和黑线仓鼠的种群数量。结果表明,此方法计算简便、准确、可靠,为鼠类种群数量的预测提供了新的方法。     

长爪沙鼠和布氏田鼠汗腺的分布与密度

哺乳动物受到高温胁迫时可通过分泌汗液调节体温。一般认为啮齿类在高温时不出汗,但有关野生啮齿类汗腺的资料不多。我们以长爪沙鼠和布氏田鼠为研究对象,采用苏木精—伊红染色方法,观察了身体各部位皮肤的形态学特征、汗腺的分布和密度。结果显示:(1)两种鼠的头部、口角、胸部、腋窝、腹部、背部和后腿部的皮肤都无汗腺分布,只在不被毛的前足与被毛的后足有外泌汗腺分布;(2)长爪沙鼠前、后足皮肤汗腺的密度分别为(2.40±0.49)个/mm2和(0.15±0.03)个/mm2,前足显著多于后足;布氏田鼠前、后足皮肤汗腺的密度分别为(0.37±0.05)个/mm2和(0.21±0.08)个/mm2,前、后足无显著差异。两种鼠前后足皮肤的汗腺密度可能与被毛状态相关,有被毛则汗腺密度低。推测长爪沙鼠和布氏田鼠前后足的汗腺可能具有辅助散热和运动时增加摩擦力等功能。     

不育剂EP - 1 对荒漠啮齿动物优势种群数量的影响

2011 ～ 2012 年在内蒙古阿拉善荒漠区,利用复合不育剂EP - 1 (左炔诺孕酮- 炔雌醚),设试验区和对照区,采用春季试验区一次性投饵的方法,对子午沙鼠、小毛足鼠和三趾跳鼠3 种荒漠啮齿动物优势种群的不育控制进行研究。结果表明,不育剂EP - 1 显著降低了优势种群当年的幼体出生率,试验区5 ～ 6 月小毛足鼠幼体比例较对照区显著降低(P < 0. 05),5 ～ 8 月子午沙鼠和6 ～ 8 月三趾跳鼠成体比例分别较对照区显著增加(P < 0. 05),同时显著降低了优势鼠种当年的种群数量,试验区子午沙鼠和小毛足鼠种群在繁殖高峰期的数量均显著低于对照区(P < 0.05),4 ～ 5 月三趾跳鼠种群数量显著低于对照区(P < 0. 05)。次年,试验区5 ～ 7 月子午沙鼠种群成体比例显著高于对照区(P < 0. 05),全年种群数量显著低于对照区(P < 0.05),而三趾跳鼠种群数量与对照区差异并不显著。因此,不育剂EP - 1 对3 种荒漠啮齿动物优势种群数量增长均具有控制作用,尤其对子午沙鼠种群的持续控制效果更加明显。可见,种群在繁殖期年龄结构的变化是影响其种群数量动态的重要因素。     

甘肃鼢鼠肾结构特征

甘肃鼢鼠(Myospalax cansus)在缺水的黄土高原营严格地下生活,主要从食物中摄取水分.为研究甘肃鼢鼠的调水机制,用组织解剖学方法对其肾的形态结构进行观察.结果显示,甘肃鼢鼠肾为单乳头肾,呈蚕豆形,表面光滑,不分叶;皮质与髓质的厚度比为0.71:1;皮质中髓旁肾单位相对分布密度小于浅表肾单位的相对分布密度;髓旁肾单位中的血管球直径大于浅表肾单位中的血管球直径;近曲小管与远曲小管的截面数量比为2.25:1.结果表明,甘肃鼢鼠肾的重吸收能力较小,其组织形态学结构有显著的生态适应意义.     

荒漠区两种优势鼠种的活动节律及其影响因子

子午沙鼠（Meriones meridianus）和三趾跳鼠（Dipus sagitta）是阿拉善荒漠区同域共存的两种优势鼠种,研究其活动节律对于了解荒漠啮齿动物的共存机制具有重要意义。本研究于2017年4月（春季）、7月（夏季）、9月（秋季）和10月（初冬）在阿拉善荒漠区,利用红外相机陷阱技术对子午沙鼠和三趾跳鼠的活动节律进行监测,以期深入了解极端干旱环境中子午沙鼠和三趾跳鼠不同季节活动节律动态,探索优势鼠种共存策略。结果表明：（1）子午沙鼠的种群数量受三趾跳鼠种群密度的抑制,其活动高峰期随三趾跳鼠活动高峰期的推迟而推迟,存在明显错峰现象,受光照强度的影响,二者的活动时长与夜长均呈正相关关系,其活动开始时间随日落时间的推迟、环境温度的升高而推迟;（2）子午沙鼠的活动强度在不同季节间无显著差异,三趾跳鼠的活动强度在不同季节有显著差异 （F=3.202;P=0.032),表现为4月>7月>9月>10月;（3）子午沙鼠和三趾跳鼠通过调整其夜间时间利用模式以减少竞争,实现同域共存。     

Water conservation in the South American desert mouse opossum, Thylamys pusilla (Didelphimorphia, Didelphidae).

The aim of this paper was to analyze the renal performance of the insectivorous desert mouse opossum, Thylamys pusilla, a marsupial that inhabits temperate drylands of the Neotropics. We measured the urine concentrating ability of this marsupial in the field and under three different experimental conditions in the laboratory. (1) Ad libitum treatment: animals were fed ad lib. on apples, sausages and cat food; (2) restriction treatment: foods high in nitrogen were supplied ad lib., while only apple, a food with high water to nitrogen load, was restricted, and (3) fasting: 2 days of food deprivation. Osmolarity values recorded in the field were similar to those obtained under the restriction treatment. The maximum urinary concentration found (9015 mOsm/l) is the highest reported for a marsupial and more in keeping with similarly sized desert rodents. Similar urine concentrations in T. pusilla and desert rodents suggest that xeric environments, rather than phylogeny, play a major role in water conservation. The kidney of T. pusilla possesses a long papilla and shows high renal indices (M/C: 9.37; RMT: 11.76). Our results question the idea that urine concentration is not high in desert-dwelling insectivores. Although their dietary water intake is potentially high, this may not always be sufficient to eliminate the nitrogenous waste resulting from insectivory. Thus, T. pusilla uses its ability to conserve water to overcome periods of food shortage and high nitrogen load.     

Ecomorphological constraints imposed by the kidney component measurements in honeyeater birds inhabiting different environments

The histological renal anatomy of 10 species of honeyeaters was examined quantitatively, using stereology. The kidneys of five species of predominantly wet zone inhabiting birds: the western spinebill Acanthorhynchus superciliosus , White-checked honeyeater Phylidonyris nigra . New Holland honeyeater Phylidonyris novaehollandiae , little wattlebird anthochaera chrysoptera and red wattlebird Anthochaera carunculata , were compared to five predominantly arid zone inhabiting birds: the grey-fronted honeyeater Meliphaga plumula , white-plumed honeyeater Meliphaga penicillata , white-fronted honeyeater Phylidonyris albifrons , spiny-checked honeyeater Acanthogenys rufogularis and yellow-throated miner Manorina flarigula. The kidneys were asymmetrical, with the left kidney being larger than the right kidney. Kidney mass was directly proportional to body mass (coefficient of correlation, r =+0·95), as was kidney volume to kidney mass (r =+1·0). Wet zone honeyeaters generally and a higher percentage and absolute volume of renal cortex, whilst arid zone honeyeaters generally had a significantly higher percentage and absolute volume of renal medulla. There were few differences between species, in either the percentage or absolute volume or luminal surface area of nephron components within the cortex. Within the medulla, wet zone honeyeaters generally had a higher percentage and absolute luminal surface area of collecting ducts, whilst arid zone honeyeaters had a higher percentage and absolute surface area of capillaries. This may be due to factors such as variations in diet and climate between habitats resulting in differences in honeyeater renal morphology which enable arid zone birds to conserve water and wet zone birds to conserve ions more efficiently.     

The water economy of South American desert rodents: from integrative to molecular physiological ecology

Rodents from arid and semi-arid habitats live under conditions where the spatial and temporal availability of free water is limited, or scarce, thus forcing these rodents to deal with the problem of water conservation. The response of rodents to unproductive desert environments and water deficits has been intensively investigated in many deserts of the world. However, current understanding of the cellular, systemic and organismal physiology of water economy relies heavily on short-term, laboratory-oriented experiments, which usually focus on responses at isolated levels of biological organization. In addition, studies in small South American mammals are scarce. Indeed xeric habitats have existed in South America for a long time and it is intriguing why present day South American desert rodents do not show the wide array of adaptive traits to desert life observed for rodents on other continents. Several authors have pointed out that South American desert rodents lack physiological and energetic specialization for energy and water conservation, hypothesizing that their success is based more on behavioral and ecological strategies. We review phenotypic flexibility and physiological diversity in water flux rate, urine osmolality, and expression of water channels in South American desert-dwelling rodents. As far as we know, this is the first review of integrative studies at cellular, systemic and organismal levels. Our main conclusion is that South American desert rodents possess structural as well as physiological systems for water conservation, which are as remarkable as those found in "classical" rodents inhabiting other desert areas of the world.     

Renal expression and functions of aquaporin 1 and aquaporin 4 in cattle

Abstract

Aquaporin (AQP) 1 and AQP 4 are members of the aquaporin water channel family that play an important role in reabsorption of water from the renal tubular fluid to concentrate urine. Studies of renal AQPs have been performed in human, rodents, sheep, dogs and horses. We studied nephron segment-specific expression of AQP 1 and AQP 4 using immunohistochemical staining on paraffin sections of bovine kidneys. AQP 1 was moderately expressed in endothelium of the cortical capillary network, vasa recta, and glomerular capillaries. AQP 4 was moderately expressed only in cytoplasm of epithelial cells in proximal tubules. We concluded that AQP 1 and AQP 4 in the bovine kidney showed some differences from other species in renal trans-epithelial water transport.     

A priori and a posteriori approaches for finding genes of evolutionary interest in non-model species: Osmoregulatory genes in the kidney transcriptome of the desert rodent Dipodomys spectabilis (banner-tailed kangaroo rat)

One common goal in evolutionary biology is the identification of genes underlying adaptive traits of evolutionary interest. Recently next-generation sequencing techniques have greatly facilitated such evolutionary studies in species otherwise depauperate of genomic resources. Kangaroo rats (Dipodomys sp.) serve as exemplars of adaptation in that they inhabit extremely arid environments, yet require no drinking water because of ultra-efficient kidney function and osmoregulation. As a basis for identifying water conservation genes in kangaroo rats, we conducted a priori bioinformatics searches in model rodents (Mus musculus and Rattus norvegicus) to identify candidate genes with known or suspected osmoregulatory function. We then obtained 446,758 reads via 454 pyrosequencing to characterize genes expressed in the kidney of banner-tailed kangaroo rats (Dipodomys spectabilis). We also determined candidates a posteriori by identifying genes that were overexpressed in the kidney. The kangaroo rat sequences revealed nine different a priori candidate genes predicted from our Mus and Rattus searches, as well as 32 a posteriori candidate genes that were overexpressed in kidney. Mutations in two of these genes, Slc12a1 and Slc12a3, cause human renal diseases that result in the inability to concentrate urine. These genes are likely key determinants of physiological water conservation in desert rodents.