树鼩的动物福利措施探讨

树鼩在生物学特性、生理生化、新陈代谢和基因组等方面近似于人类,被广泛应用于生理学、病理学、病毒学、免疫学、药理学及遗传学等多个领域。迄今为止用于生物医学研究的树鼩大部分来自野生,实验树鼩尚无国家质量控制标准。为了保证树鼩引种、驯化、饲养、繁殖、质量控制及福利的规范化和科学化,提高树鼩繁殖率和成活率,本文从兽医公共卫生及实验动物科学的角度,对野生树鼩的捕捉、运输、检疫、饲养及繁育等方面的基本原则及技术操作和福利要求作一简述,为从事树鼩工作的有关人员及树鼩实验动物化研究提供参考。     

Serum cholesterol of Malayan tree shrews

Subspecific differences were found in total and esterified cholesterol of Malayan tree shrews. Thirty-twoT. glis sordida (Tioman Island) had mean levels of 73.4 mg% total cholesterol and 50.6 mg% esterified cholesterol. Mean levels of 57.3 mg% total cholesterol and 38.2 mg% cholesterol esters were found in 25T. g. ferruginea from the Malayan mainland. Other factors such as sex, pregnancy, and perhaps stress as related to diet and density of population, appeared to contribute to the variance of cholesterol level between insular and mainland forms.     

Sexual dimorphism of sublingual glands in tree shrews

On the basis of histochemical characteristics it was possible to demostrate a sexual dimorphism of the tree shrew sublingual gland. Although numerous staining methods for the demonstration of mucosubstances were used in this study, only methods for the demonstration of sulfated glycoproteins (sulfomucins) were effective in demonstrating the sexual dimorphism. Numerous sulfomucin-laden cells occurred in the mucous tubules and acini of female sublingual glands, but only rarely were such cells observed in sublingual glands of male animals. Neither duct cells nor demilune cells of secretory endpieces were involved in the sexual dimorphism. No morphological sexual dimorphism was noted in tree shrew sublingual glands.     

Comparative cytogenetic studies in tree shrews (Tupaia).

Through use of BrdU replication, RBA-banded karyotypes of Tupaia belangeri, T. chinensis, and T. glis were obtained. A chromosome number of 2n = 62 for T. belangeri is described here for the first time and is confirmed for T. chinensis. All chromosomes between these two phenotypically different species appear to have identical RBA banding patterns; in addition, there is no difference between T. belangeri and T. chinensis in the number and position of nucleolus organizer regions (NORs). The reduced chromosome number of 2n = 60 in T. glis can be explained by a Robertsonian translocation between two acrocentric chromosome pairs, Nos. 10 and 13, of T. belangeri and/or T. chinensis, resulting in the metacentric chromosome pair 1 of T. glis. Furthermore, two chromosome pairs each of T. glis and T. belangeri and/or T. chinensis are not homoeologous, as judged by their RBA patterns. Differences were also found in the number and position of NORs; whereas T. glis displays eight positively stained NORs after AgNO3 staining, there are only four silver-stained NORs in both T. belangeri and T. chinensis. The possibility of geographical isolation as an explanation for the lack of chromosomal differentiation between T. belangeri and T. chinensis is discussed.     

Social system and independence of offspring in tree shrews

Field observations on 117 tree shrews (Tupaia glis) were conducted over a period of six months in Singapore. Of 19 groups (pairs or harems, with or without offspring), nine changed their composition mainly through the disappearance of juveniles. Juvenile males tended to disappear earlier than juvenile females. The areas used by the groups remained stable throughout their disappearance and membership changes. The onset of mating was observed in December, and the synchronous disappearance of offspring of the preceding reproduction typically occurred in late January. However, in one group, two litters coexisted. Offspring were usually excluded from their group presumably by the adult member of the same sex. Males disappeared at the timing of oestrus in their mothers, while females probably disappeared during the later stages of pregnancy of their mothers.     

Cystathionine in the brains of tree shrews and other mammals

The amino acid cystathionine is reported to show higher concentrations in the brains of man as compared to those of other species. Two-dimensional separation by electrophoresis-chromatography and densitometric analysis of amino acids showed that the brains of tree shrews had levels of cystathionine intermediate between those of man and other mammals such as tamarins, hedgehogs, and rats. Cystathionine may be involved in the circadian rhythms ofTupaiidae. In man a 10 fold variation in cerebral cystathionine is related to pathological conditions. Greater concentrations in white matter as compared to grey matter and other regional differences in brain tissue support the findings from inherited disorders that cystathionine plays an important role in the normal as well as the abnormal functioning of the brain.     

Jugulo-sternal-gland tumors in male tree shrews (Tupaia belangeri).

Adenocarcinomas of the jugulo-sternal glands were observed in seven adult male tree shrews (Tupaia belangeri) at biopsy or necrospy. Five of these tumors were classified as carcinomas of the sebaceous gland compartment; one was diagnosed as a papilliform adenoma of apocrine (monoptychic) sweat glands; and one was of a mixed sebaceous gland/apocrine sweat gland structure. Four sebaceous gland carcinomas had histologic evidence of vascular invasion; one had metastasized to the regional lymph nodes and lungs and had also invaded the thoracic muscles.     

树鼩解剖数据的测定与分析

解剖数据是实验动物主要的生物学特性指标。该文对实验室驯养树鼩(7～9月龄)的体尺、骨骼、乳头、肠道及脏器重量与系数等解剖学数据进行了测定与分析。31项解剖数据测量结果显示雌、雄个体间体高、右耳宽、回肠及结肠差异显著(P<0.05),体斜长、胸深、躯干长、左右两前肢长、右后肢长、左右两侧耳长、左耳宽、龙骨长、左右两侧胫长、十二指肠及空肠长等差异极显著(P<0.01)。以体长为因变量,尾长、躯干长、左前肢长、右前肢长、左后肢长及右后肢长等为自变量作逐步回归分析,回归方程为:体长=13.90+尾长×0.16。37项脏器及系数测定结果:雌雄间比较,体重、心、肺、脾、左肾、右肾、膀胱、左海马、右海马、左颌下腺、左甲状腺、右甲状腺重量差异极显著(P<0.01)。小肠、右颌下腺、左肾上腺之间差异显著(P<0.05);心、肺、胃、膀胱、小肠、大肠、脑、右海马、左肾上腺系数雌雄间差异极显著(P<0.01)。右肾、左海马、左颌下腺、右肾上腺、左右两侧甲状腺系数之间达到了显著性水平(P<0.05)。以动物体重为因变量,以主要脏器指标:心脏、肺、肝、脾、左肾、右肾、脑为自变量,作逐步回归分析,回归方程为:体重=62.73+左肾×79.213+心脏×24.09。实验室驯养树鼩不同性别对体尺、脏器及系数、肠道等解剖数据有一定影响,为树鼩实验动物化及人类疾病动物模型研究提供基础数据。     

Common tree shrews and primates share leukocyte membrane antigens

Monoclonal antibodies reactive with human peripheral blood lymphocyte and myeloid cell surface antigens were utilized to study the phylogeny of the common tree shrew. Blood cells from the common tree shrew, but not the bat or short-tailed shrew, react with certain of these antibodies. These data strengthen the argument that the Tupaiidae are primitive primates rather than insectivores. They also indicate that this approach should be useful for further work in taxonomic systemization.     

树鼩进化分类地位的分子证据

树鼩隶属攀鼩目,广泛分布于东南亚、南亚和中国南部等地区。由于其独特的特点,如体型小、脑-体重比例高、生殖周期短、寿命短和饲养成本低等,在生物医学研究中被认为是可望替代灵长类动物的新型实验动物。然而,关于树鼩与灵长类动物的亲缘关系一直存在争议。明确树鼩的分类地位是创建实验动物的重要研究基础。该文介绍了近年来关于树鼩分类地位探讨的分子证据。在现有的研究中,大部分核DNA序列研究,包括近期树鼩全基因组序列分析,都支持树鼩是灵长动物的近缘旁系群,然而绝大部分基于线粒体DNA序列的研究却显示树鼩与啮齿动物的亲缘关系更为接近。这样的分歧主要是由于线粒体序列和核基因数据的差异以及不同的算法导致。综合现有不同DNA数据的研究结果,作者认为树鼩作为灵长类的近亲这一结论应该成为共识。     

Louse infestations of tree shrews (Tupaia glis)

Nine adult tree shrews, Tupaia glis, recently imported from West Malaysia were visually examined for ectoparasites while under general anesthesia. Three shrews were infested by the sucking louse, Sathrax durus , and six shrews had louse ova belonging to this species; two shrews had neither lice nor ova. A total of 20 adult female, 10 adult male, and three third instar nymphal lice was collected. Lice were located on the head, flanks, and dorsal body of shrews while ova were recorded mainly from the anterior flanks but also from some adjacent host sites. The tree shrews appeared to tolerate the lice well although louse vector capacity was not assessed. The last date that lice were recorded from shrews was 22 days after colony set-up, and the last date on which seemingly viable ova were recorded was 64 days after set-up showing that the infestations were ultimately lost.     

树鼩血压和心率的无创测定

目的建立健康树鼩的心率、血压正常值参考范围,并探讨不同来源、不同性别、不同年龄树鼩心率、血压的差异。方法随机挑选实验树鼩180只,按来源分为野生成年组、F1代自繁成年组和青幼年组三个组,每组雌雄各半,共60只。采用智能无创血压计（鼠仪）逐只测定HR（心率）、SBP（收缩压）、DBP（舒张压）和MBP（平均动脉压）。结果野生成年树鼩、自繁成年树鼩和青幼年树鼩心率分别为394.33±37.74 BPM、351.61±72.76 BPM和378.19±69.04 BPM,野生和自繁成年树鼩组差异有显著性（P〈0.05）。自繁成年树鼩收缩压、舒张压和平均动脉压均明显低于青幼年树鼩,差异有极显著性（P〈0.01）。野生成年树鼩和自繁成年树鼩相比,收缩压、舒张压和平均动脉压差异均无显著性（P〉0.05）。结论大鼠无创血压计适合于树鼩的血压、心率的测量。通过测定,获得了野生成年树鼩、F1代自繁成年树鼩和青幼年树鼩的心率和血压参考值范围,丰富了树鼩基础生理数据,可为相关研究提供科学参考。     

Cryopreservation of epididymal sperm in tree shrews (Tupaia belangeri)

Cryopreservation of sperm from tree shrews, which are considered primitive primates, would enhance genetic management and breeding programs. Epididymal sperm were surgically harvested from male tree shrews, cryopreserved in two Tes-Tris-based cryodiluents, and used in four experiments. In Experiment 1, there were no significant differences in motility and acrosome integrity among five concentrations of egg yolk in TTE after cooling to 4 °C. However, sperm frozen in TTE containing 20% egg yolk at −172 °C/min had better (P < 0.05) post-thaw motility and acrosome integrity. In Experiment 2, sperm held for 10 min prior to storage in liquid nitrogen had greater motility than those held for 5 or 15 min (P < 0.05), but acrosome integrity was not different (P > 0.05) among treatments. In Experiment 3, sperm frozen in TTE diluent had higher (P < 0.05) motility and acrosome integrity than those in TEST diluent. In Experiment 4, there were no differences (P > 0.05) in the fertilization rate of oocytes and the proportion of tree shrews yielding fertilized oocytes, following AI with fresh versus frozen sperm. In conclusion, tree shrew epididymal sperm were successfully cryopreserved, as assessed by post-thaw motility, acrosome integrity, and fertilizing ability.     

社会竞争失败病因学的抑郁症树鼩模型

抑郁症是一种常见精神疾病,主要表现为持续两周以上的情绪低落。世界卫生组织预测在2030年抑郁症的疾病负担将高居所有疾病、伤残总负担的榜首。抑郁症面临三大难题:1)发病机理不完全清楚,因而缺乏有效的预测预防途径和生物学诊断;2)现有单胺类抗抑郁症药物起效慢,也可能导致患者自杀风险增加;3)缺乏副作用小的非单胺类快速起效抗抑郁症药物。针对这三大难题,长期以来,应用抑郁症啮齿类模型的众多研究并未取得实质性进展,至少部分因素归咎于啮齿类与人类大脑功能的极大种属差异。树鼩是灵长类近亲,具有更接近于人类的大脑功能。本文针对抑郁症发病机理假说、临床表象和抗抑郁症药物疗效等内容,综述了社会竞争失败病因学的抑郁症树鼩模型可能会具有更好的疾病同源性、表象一致性和药物预见性。这一被长期忽视的抑郁症树鼩模型尽管还需要进一步完善,但对其进一步深入研究可能为解决抑郁症的三大难题提供了一条新途径。