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。     

白腹鼠属几个相似种的差异探讨

到目前为止,安氏白腹鼠、川西白腹鼠、社鼠、针毛鼠作为独立种没有多大的争议。但在形态上,安氏白腹鼠与川西白腹鼠、川西白腹鼠与社鼠、社鼠与针毛鼠具有较大的相似性,差异微小,有大量的中间过渡类型。因此,要对这些种进行准确鉴定非常困难。本文首先对这4个种的阴茎形态进行了比较,发现它们确实是独立的种。它们之间的主要区别在于尿道小瓣形态、位置及阴茎骨形态和长短比例上：（1）安氏白腹鼠,外环层有明显的乳突,尿道小瓣分两叉,位置很低,阴茎骨近支显著长于远支;（2）川西白腹鼠,外环层光滑,尿道小瓣位置较高,阴茎骨近支很细而直,近支明显长于远支;（3）社鼠,尿道小瓣较小,位置很低,呈舌状,阴茎骨近支较粗,显著向腹面弯曲,远支粗大且较长,近支长略大于远支;（4）针毛鼠,尿道小瓣位置较高,呈舌状,阴茎骨近支较细弱,显著向腹面弯曲,远支粗大且较长。采用单因素方差分析发现,川西白腹鼠与社鼠在眶间宽、上齿列长和下齿列长等方面差异显著;社鼠和针毛鼠在后头宽、眶间宽和听泡长等方面差异显著;安氏白腹鼠与其他3个种均具有显著的差异。     

应用阴茎骨鉴定雄性褐家鼠年龄组的探讨

1986年10-11月,作者在长春市研究了城市褐家鼠的种群生态。获得标本 1,214号(531,683),解剖、测量、记录了雄性睾丸重量、长度和宽度,制取了雄性阴茎骨。对其种群阴茎骨长度作了分析,并依据阴茎骨长度作褐家鼠的频数分配,对照体长、体重、睾丸及头骨等特征,划分5个年龄组。分析结果表明,应用雄性褐家鼠阴茎骨划分年龄组,其组间差异显著,组间交叉不大,相对准确,能比较接近实际年龄,故用阴茎骨长度作为划分褐家鼠种群年龄组标准是可行的。     

灰鼠的年龄鉴定及种群组成

灰鼠(Sciurus vulgaris)是我国重要毛皮兽之一。为了更好的利用,掌握其种群动态规律是必要的。种群年龄组成是种群动态特征之一。因而,对灰鼠种群年龄的研究,有一定的意义。有关灰鼠年龄的研究报道不多。国外对黑松鼠(Sciurus niger)、北美灰松鼠(S.carolinensis)的年龄组划分吋,多以长骨骺骨的骨化程度、雄性阴茎骨的形态特征及其重量和长度的差异、水晶体的干重、尾毛的特征等作为指标的依据(Petrides 1951; Carson1961; Kirkpatrick等1957; Beale 1962),但年龄组划分的结果,多限于成年与幼年两组,     

粤西发现的黑腹绒鼠及其生态学的初步调查报告

黑腹绒鼠(Eothenomys melanogaster)据秦耀亮报道,见于粤北海拔1,922米的石坑埪。1958年以来,我们先后在粤北石坑埪箭竹林和粤西大雾岭草丛捕获黑腹绒鼠13只,最近又在粤西大雾岭作了一些生态学方面的调查。结果报告如下。     

四川唐家河自然保护区黑腹绒鼠对夏季生境的选择

为揭示影响黑腹绒鼠夏季空间分布的生态因素,采用样线法和样方取样法,于2009年6～8月在四川省唐家河国家级自然保护区对该物种夏季生境选择进行了研究.野外工作期间,共调查生境样方和对照样方各58个.在21个生境变量中,海拔、坡度、坡向等16个变量在生境样方和对照样方间存在显著差异,表明该地黑腹绒鼠对夏季生境的利用具有明显的选择性.该地黑腹绒鼠夏季频繁出现的生境为:坡向朝南,偏好选择处于较早植被演替阶段,海拔较低,乔木和竹子较矮,离水源较近,乔木层郁闭度、乔木胸径、竹子盖度、竹子密度和落叶层盖度较小,而草本层较高,草本盖度、密度及灌木密度均较大.Logistic回归分析表明坡向和草本盖度是影响该地黑腹绒鼠夏季生境选择的主要生态因子,可能反映了来自食物丰富度和捕食两方面的选择压力决定着该物种空间分布.在此基础上构建了黑腹绒鼠夏季生境资源选择函数logit(P)=8.027+2.792×草本盖度+0.325×坡向,其对生境的选择概率为P=elogit(P)/(1+elogit(P)),可用于预测夏季黑腹绒鼠在该保护区内的空间分布.     

黑腹绒鼠生态学的研究

黑腹绒鼠(Eothenomys melanogaster)是我国南方较常见的鼠种之一,多栖居在海拔较高的山地,且数量较少。我们于1981年1月至1982年1月、1984年7月和11月在浙江西天目山以及1984年3月至12月在金华的北山对黑腹绒鼠作了生态学的调查,现将结果报告如下。     

鼩鼱科内6 个种的阴茎形态学

阴茎形态学特征是研究哺乳动物亲缘关系的有力工具,尤其是在近缘种之间。本试验选取鼩鼱科内的黑齿鼩鼱(Blarinella quadraticauda)、小纹背鼩鼱(Sorex bedfordiae)、大纹背鼩鼱(S. cylindricauda)、云南鼩鼱(S. excelsus)、四川短尾鼩(Anourosorex squamipes)和灰麝鼩(Crocidura attenuata)6 个种共31 号阴茎标本观察其阴茎形态学特征。研究结果表明:这6 个种的阴茎均缺乏阴茎骨;在6 个种的阴茎横切面上,尿道靠近阴茎腹侧面为阴茎海绵体包裹,没有单独的尿道海绵体存在,输精管由阴茎海绵体包裹,在阴茎末端形成两条输精管侧支;黑齿鼩鼱的阴茎具有独特的舌状结构,可作为鉴定黑齿鼩鼱的一个重要特征,鼩鼱属内的小纹背鼩鼱、大纹背鼩鼱和云南鼩鼱的阴茎头界限很难观察到,而黑齿鼩鼱、四川短尾鼩和灰麝鼩的阴茎头则具有明显的界限。     

沟牙田鼠的形态特征及分类地位探讨

沟牙田鼠是分布于中国四川西部和甘肃南部的一种罕见小型啮齿动物,迄今标本收藏甚少,种、属地位存在异议,有人认为应并入田鼠属。我们根据四川九寨沟自然保护区采到的16号不同年龄、性别的沟牙田鼠,就其牙齿形态和成年雄性的阴茎结构与其它田鼠类作了比较,发现其成体和幼体在M³和M₃形态上有很大不同。其他重要区别包括：上门齿宽大;下门齿外露部分很短,下门齿总长仅及下颌长的77％左右,远比其他田鼠小;M齿环呈圆弧形或豆形亦很特殊;成年雄性的阴茎骨近支烧瓶状,远支基部膨大与田鼠类差别很大。结果表明：沟牙田鼠属是有别于田鼠属的有效属。     

黑腹绒鼠的代谢产热特征及其体温调节

为探讨东洋界华中区黑腹绒鼠的代谢产热特征及体温调节,本文采用封闭式流体压力呼吸仪对其代谢率、热传导和体温等热生物学指标进行了测定.结果显示:在环境温度为5～25℃的范围内,黑腹绒鼠的体温基本维持恒定,平均体温为36.5±0.1℃;热中性区为25～30℃;基础代谢率为2.99±0.09 ml O2/(g·h);环境温度(Ta)在5～25℃范围内,代谢率(MR)与Ta呈负相关,回归方程为:MR[ ml O2/(g·h)]= 6.56-0.16 Ta(℃),在此范围内,黑腹绒鼠的热传导率C最低,平均为0.26±0.01 ml O2/(g·h·℃).黑腹绒鼠的基本热生物学特征为:较高的BMR、热传导率和体温以及较宽的热中性区.     

铜绿微囊藻对轮虫生命表参数和表型特征的影响

为评价铜绿微囊藻的有毒(Microcystin-producing Microcystis aeruginosa)、无毒(Microcystin-free M. aeruginosa)品系对轮虫种群增长和表型特征的影响, 研究探讨了萼花臂尾轮虫(Brachionus calyciflorus)在不同微囊藻溶液中的生活史参数及形态变化。实验中各处理组单位体积总含碳量为(20.61±0.15) g C/mL, 以使轮虫获得等碳量的食物供应。实验组轮虫分别用蛋白核小球藻(Chlorella pyrenoidosa)、斜生栅藻(Scenedesmus obliquus)、有毒和无毒微囊藻溶液单独投喂, 并用有毒、无毒蓝藻菌分别与不同绿藻的混合液投喂。生命表实验结果表明, 不同微囊藻混合液投喂的轮虫净生殖率R₀ (F=102.71, df=32, P<0.001)、世代时间T (F=17.05, df=32, P<0.001)和内禀增长率r_m(F=18.89, df=32, P<0.001)与对照组相比降低1.36%—210.34%。侧棘刺长(F=28.18, df=65, P<0.001)和游泳速度(F=181.69, df=65, P<0.001)下降2.63%—39.07%, 轮虫体长(F=690.04, df=65, P<0.001)变化显著。与绿藻投喂的轮虫参数值相比, 轮虫的生命表参数和表型特征变化规律随微囊藻溶液浓度改变。萼花臂尾轮虫受到铜绿微囊藻胁迫时, 生长繁殖受到抑制并通过改变自身形态以抵御不利的生存环境。     

中国13种鼠科啮齿动物的阴茎形态学及其分类学意义的探讨

本文对我国所产13种鼠科啮齿类进行了阴茎形态学的比较研究(包括阴茎骨和软体结构),探讨了在鼠科的家鼠属(Rattus)、姬鼠属(Apodemus)、小家鼠属(Mus)和巢鼠属(Micromys)4个属间以及同属不同种之间的差异。结果表明,阴茎的形态结构具有属和种的特异性和稳定性,可以为分类学的研究提供重要依据。     

瓦氏黄颡鱼的繁殖生物学研究

研究了长江中游嘉鱼至新滩口江段瓦氏黄颡鱼的繁殖生物学。性腺发育可分为6个时期。4-7月性成熟系数较高,为繁殖季节。雌、雄鱼的肥满度和脂肪系数在繁殖前和繁殖后各出现1个峰值,繁殖期出现最小值。绝对繁殖力为1088-19765(粒),平均7728±4093(粒);相对繁殖力为23-88(粒),平均55±16(粒)。绝对繁殖力与体长、体重和年龄呈显著的正相关,其中体重与绝对繁殖力的关系最密切。群体性比接近1:1。属一次性产卵类型。两性最小性成熟年龄均为2龄。为补充群体占优势的繁殖群体。     

人工饲养条件下高原鼠兔生长和发育的初步研究

本文研究了人工饲养条件下高原鼠兔的生长发育情况,并和其他种鼠兔的生长作了比较。室内高原鼠兔比野外的生长快,人工饲养的阿富汗鼠兔和北美鼠兔生长期短,成熟早。     

It's all relative: allometry and variation in the baculum (os penis) of the harp seal, Pagophilus groenlandicus (Carnivora: Phocidae)

We compared allometry and variation in the baculum (os penis), mandible, and humerus of the harp seal, Pagophilus groenlandicus. This species is presumed to have a promiscuous mating system in which choice of mate by females during intromission with different males is likely. The baculum is large and grows throughout life so may be an honest indicator of males' quality (size) or viability (age). We predicted that bacular size would exhibit stronger allometry relative to body size than mandibles or humeri. The baculum is less functionally (mechanically) constrained than mandibles or humeri so we also predicted it would be more variable, though less variable than sexually selected traits which do not function as honest indicators. Our sample (N=67 seals) represented broad ranges of size and age (0–35 yr) so we compared variation using residuals from allometric regressions of skeletal measurements on body length. Bacular size was isometric to body length until ∼ 137 cm (when some seals enter puberty) in body length then was highly positively allometric; mandibular and humeral size were negatively allometric to body length throughout growth. Bacula were more variable than mandibles or humeri. Bacular size in large specimens (>137 cm in body length) was related strongly to body length and weakly to age. We interpret bacular size to be an uncheatable honest indicator of male quality and viability. High bacular variation conforms with theoretical predictions of females' asymmetrical choice of mate and choice of extremes, and may reflect corresponding anatomical variation among females. Some bacular variation may also result incidentally from positive allometry coupled with lifelong bacular growth, which can amplify early differences between reproductive and somatic growth, enabled by weak selection on bacular form in relation to function.     

Follicular dynamics and dominance in Booroola x Finnish Landrace and Booroola x Suffolk ewes heterozygous for the F gene

To study the influence of the F gene on follicular dynamics and dominance, 2-year-old Booroola x Finnish Landrace (BFL, N = 17) and Booroola x Suffolk (BS, N = 18) ewes were compared with contemporary purebred Finn (FL, N = 18) and Suffolk (S, N = 18) ewes. In Exp. 1, oestrous cycles of ewes were synchronized during the breeding season with progestagen-impregnated sponges. At sponge removal (Day 0), 14 days after insertion, ewes of each of the 4 genetic groups were assigned to Group 1 in which all follicles visible on both ovaries were destroyed by electrocauterization except for the largest (F1) which was marked, Group 2 in which all visible follicles on both ovaries were destroyed, or Group 3 in which the 3 largest follicles of both ovaries were identified as F1, F2 and F3 and marked. At 48 h after treatment (Day 2), follicular growth was evaluated. At Day 0, the mean number of small follicles (1-3 mm) was higher (P less than 0.05) for BS, S and BFL (35.8, 35.1 and 32.9) than FL (24.9) ewes. Large follicles (greater than or equal to 4 mm) were more numerous (P less than 0.05) in FL (3.5) than in BS (2.1) ewes, BFL and S ewes being intermediate. Diameter of the F1 follicle was larger (P less than 0.05) for S (7.6 mm) than FL, BS and BFL (5.8, 5.1 and 5.1 mm) ewes. In Group 1, all F1 follicles marked at Day 0 ovulated at oestrus after sponge removal for BFL, BS and S ewes while in FL ewes, 2 of 6 F1 follicles regressed. In ewes ovulating, only the F1 follicle ovulated except for one S ewe which shed one more ovum. In Group 2, there were no follicles greater than or equal to 4 mm at Day 2 and no ewes ovulated after treatment. In Group 3, the proportion of marked follicles that ovulated was higher for S ewes than in those of the prolific genotypes. The number of follicles not marked at Day 0 but ovulating (compared to the total number of ovulations) was higher in BFL, BS and FL (8/11, 9/13 and 9/13) than S (3/10) ewes. In Exp. 2, prolific (BFL + BS) and non-prolific (S) ewes were compared following destruction of follicles greater than or equal to 3 mm with the F1 left intact (Treatment 1) or destroyed (Treatment 2), 12 days after sponge insertion.(ABSTRACT TRUNCATED AT 400 WORDS)     

Individual differences in allocation of funds in the dictator game associated with length of the arginine vasopressin 1a receptor RS3 promoter region and correlation between RS3 length and hippocampal mRNA

Human altruism is a widespread phenomenon that puzzled evolutionary biologists since Darwin. Economic games illustrate human altruism by showing that behavior deviates from economic predictions of profit maximization. A game that most plainly shows this altruistic tendency is the Dictator Game. We hypothesized that human altruistic behavior is to some extent hardwired and that a likely candidate that may contribute to individual differences in altruistic behavior is the arginine vasopressin 1a (AVPR1a) receptor that in some mammals such as the vole has a profound impact on affiliative behaviors. In the current investigation, 203 male and female university students played an online version of the Dictator Game, for real money payoffs. All subjects and their parents were genotyped for AVPR1a RS1 and RS3 promoter-region repeat polymorphisms. Parents did not participate in online game playing. As variation in the length of a repetitive element in the vole AVPR1a promoter region is associated with differences in social behavior, we examined the relationship between RS1 and RS3 repeat length (base pairs) and allocation sums. Participants with short versions (308-325 bp) of the AVPR1a RS3 repeat allocated significantly (likelihood ratio = 14.75, P = 0.001, df = 2) fewer shekels to the 'other' than participants with long versions (327-343 bp). We also implemented a family-based association test, UNPHASED, to confirm and validate the correlation between the AVPR1a RS3 repeat and monetary allocations in the dictator game. Dictator game allocations were significantly associated with the RS3 repeat (global P value: likelihood ratio chi(2) = 11.73, df = 4, P = 0.019). The association between the AVPR1a RS3 repeat and altruism was also confirmed using two self-report scales (the Bardi-Schwartz Universalism and Benevolence Value-expressive Behavior scales). RS3 long alleles were associated with higher scores on both measures. Finally, long AVPR1a RS3 repeats were associated with higher AVPR1a human post-mortem hippocampal messenger RNA levels than short RS3 repeats (one-way analysis of variance (ANOVA): F = 15.04, P = 0.001, df = 14) suggesting a functional molecular genetic basis for the observation that participants with the long RS3 repeats allocate more money than participants with the short repeats. This is the first investigation showing that a common human polymorphism, with antecedents in lower mammals, contributes to decision making in an economic game. The finding that the same gene contributing to social bonding in lower animals also appears to operate similarly in human behavior suggests a common evolutionary mechanism.