大绒鼠解偶联蛋白1基因部分序列扩增与分析

解偶联蛋白1（Uncoupling protein 1,UCP1）是位于褐色脂肪组织线粒体内膜上的一种解偶联蛋白,该蛋白可以诱导质子漏从而产热。通过设计简并引物进行RT-PCR从大绒鼠BAT中获得UCP1基因cDNA核心序列,RTPCR所得产物长约458 bp,包含的开放阅读框（open reading frame,ORF）为456 bp,编码151个氨基酸。通过BLAST搜索,所得大绒鼠UCP1基因cDNA氨基酸序列与黑线仓鼠、橙腹草原田鼠、金黄仓鼠、小家鼠和褐家鼠等哺乳动物的UCP1氨基酸序列同源性均在80%以上,而与鱼类和两栖类的氨基酸序列同源性在61%以下。研究结果表明UCP1在哺乳类中高度保守。同时,通过NJ方法以UCP1序列构建系统进化树表明大绒鼠与橙腹草原田鼠聚成一支,构成田鼠类分支。     

绒鼠属(Eothenomys Miller,1896)系统学研究概况

绒鼠属于1896年建立?针对该属有几个亚属、多少个有效种的问题100多年来一直争论不休,一般认为该属有3个亚属：Eothenomp亚属、Anteliomys亚属,和Caryomys亚属。部分人认为只有前两个亚属;少数人认为没有亚属分化。至于该属的种类争论更大,命名的种类多达20个,但没有一人同时承认20个种,比较多数人认为有11个种。我们通过研究该属部分种的阴茎形态学认为：该属有3个亚属,即Eothenomys亚属、Anteliomys亚属、和Caryomys亚属。     

黑腹绒鼠消化道长度和重量的季节变化

能量获得与分配的效率和速率是决定动物能量收支的主要因子,对于动物的生存和繁殖是至关重要的（Karasov, 1986;Weiner,1992）.动物的消化道容纳和处理食物的能力,以及消化和吸收营养物质的能力是限制其能量收支的重要因素,也是理解生活史进化和最优资源分配理论的关键（Derting and Bogue,1993;Derting and Noakes,1995）.     

大绒鼠体温调节和产热特征

大绒鼠为横断山脉地区小型哺乳动物的典型代表; 其体温仅能在15～30℃范围内维持稳定; 在热中性区内, 最低静止代谢率为2.71±0.13 ml O₂/g.h, 为其体重预期值的203.2±10.13%; F-值 {(RMR/Me)/(Cm/ C'} 为0.99±0.05; 在 25℃的NSTmax为 5.18±0.19)ml O₂/g.h; BAT 重量为0.33±0.05 g, 为体重的0.84%, BAT细胞线粒体的产热活性较高;肝脏也具有较强的产热活性。大绒鼠的产热特征和体温调节模式很可能反映了横断山地区小型啮齿动物的特征。     

横断山两种小型哺乳动物的蒸发失水与体温调节

在实验室条件下测定了大绒鼠和高山姬鼠在不同温度下的蒸发失水与能量代谢.结果表明:大绒鼠和高山姬鼠的热中性区分别为22.5～30℃和25～30℃;平均体温分别为36.12℃和36.17℃;大绒鼠和高山姬鼠的基础代谢率(BMR)分别为2.99±0.48 ml O2/g ·h和4.24±0.50 ml O2/g·h;大绒鼠和高山姬鼠的平均最小热传导(Cm)分别为0.26±0.038 ml O2/g·h·℃和0.32±0.034 ml O2/g·h·℃;大绒鼠和高山姬鼠的蒸发失水随着温度增高而增加,大绒鼠的蒸发失水在30 ℃达高峰值,为10.32 mg H2O/g·h,高山姬鼠在35℃达高峰值,为14.57mg H2O/g·h;大绒鼠和高山姬鼠的热散失占总产热的比率随着温度增高而增加,大绒鼠在30 ℃达到最大为34.6%,高山姬鼠在35℃达到最大为37.5%.这些结果很可能反映出横断山小型啮齿类动物的特征,即体温相对较低,代谢水平较高,热传导也较高,蒸发失水在总产热中占有重要的地位.     

夏季横断山不同地区大绒鼠脏器和消化道形态的差异

正随着全球气候变化的日趋加剧,动物对环境变化的反应模式和机制引起了越来越多研究者的兴趣(Canale and Henry,2010)。能量的获取与消耗是动物生存的关键,同时也是维持体重平衡的关键(Wang et al.,2003)。消化系统表型可塑性是动物个体的适应性特征,能帮助它们应对食物资源的变     

长爪沙鼠阴茎头的组织学研究及五种鼠阴茎头的扫描电镜观察

本文对８例长爪沙鼠（Ｍｅｒｉｏｎｅｓｕｎｇｕｉｃｕｌａｔｕｓ）幼年、亚成年、成年和老年雄性个体的阴茎头组织进行连续切片。结果表明,阴茎头的外环层和阴茎骨近支由阴茎海绵体衍生而来;内环层、尿道小瓣、阴茎骨远支和侧支由尿道海绵体衍生而成。采用扫描电镜观察了长爪沙鼠、子午沙鼠（Ｍ．ｍｅｒｉｄｉａｎｕｓ）、大沙鼠（Ｒｈｏｍｂｏｍｙｓｏｐｉｍｕｓ）和甘肃绒鼠（Ｅｏｔｈｅｎｏｍｙｓｅｖａ）、黑腹绒鼠（Ｅ．ｍｅｌａｎｏｇａｓｔｅｒ）共５种１６例的阴茎头表皮棘,发现其形态、数量和分布有属、种间差异性和相对稳定性,沙鼠属（Ｍｅｒｉｏｎｅｓ）３种的表皮棘均呈牛角状的圆锥体,斜向排列成行;而绒鼠属（Ｅｏｔｈｅｎｏｍｙｓ）内甘肃绒鼠为球状表皮棘,黑腹绒鼠为牛角状,排列均不规则。因此,阴茎头表皮棘与阴茎骨、阴茎头软体结构均有分类学意义。     

Metabolism,thermoregulation and evaporative water loss in the Chaotung Vole (Eothenomys olitor) in Yunnan-Kweichow Plateau in summer

Proper adjustment of thermoregulatory mechanisms ensures the survival of mammals when they are subjected to seasonal changes in their natural environment. To understand the physiological and ecological adaptations of Eothenomys olitor, we measured their metabolic rate, thermal conductance, body temperature (T_b) and evaporative water loss at a temperature range of 5–30 °C in summer. The thermal neutral zone (TNZ) of E. olitor was 20–27.5 °C, and the mean body temperature was 35.81±0.15 °C. Basal metabolic rate (BMR) was 2.81±0.11 ml O₂/g h and mean minimum thermal conductance (C_m) was 0.18±0.01 ml O₂/g h °C. Evaporative water loss (EWL) in E. olitor increased when the ambient temperature increased. The maximal evaporative water loss was 6.74±0.19 mg H₂O/g h at 30 °C. These results indicated that E. olitor have relatively high BMR, low body temperature, low lower critical temperature, and normal thermal conductance. EWL plays an inportant role in temperature regulation. These characteristics are closely related to the living habitat of the species, and represent its adaptive strategy to the climate of the Yunnan-Kweichow Plateau, a low-latitude, high-altitude region where annual temperature fluctuations are small, but daily temperature fluctuations are greater.     

Evaporative water loss and energy metabolic in two small mammals,voles (Eothenomys miletus) and mice (Apodemus chevrieri), in Hengduan mountains region

Evaporative water loss (EWL) and energy metabolism were measured at different temperatures in Eothenomys miletus and Apodemus chevrieri in dry air. The thermal neutral zone (TNZ) of E. miletus was 22.5–30 °C and that of A. chevrieri was 20–27.5 °C. Mean body temperatures of the two species were 35.75±0.5 and 36.54±0.61 °C. Basal metabolic rates (BMR) were 1.92±0.17 and 2.7±0.5 ml O₂/g h, respectively. Average minimum thermal conductance (C_m) were 0.23±0.08 and 0.25±0.06 ml O₂/g h °C. EWL in E. miletus and A. chevrieri increased with the increase in temperature; the maximal EWL at 35 °C was 4.78±0.6 mg H₂O/g h in E. miletus, and 5.92±0.43 mg H₂O/g h in A. chevrieri. Percentage of evaporative heat loss to total heat production (EHL/HP) increased with the increase in temperature; the maximal EHL/HP was 22.45% at 30 °C in E. miletus, and in A. chevrieri it was 19.96% at 27.5 °C. The results may reflect features of small rodents in the Hengduan mountains region: both E. miletus and A. chevrieri have high levels of BMR and high levels of total thermal conductance, compared with the predicted values based on their body masses, while their body temperatures are relatively low. EWL plays an important role in temperature regulation.