Establishment of basal cell carcinoma animal model in Chinese tree shrew (Tupaia belangeri chinensis)

Basal cell carcinoma (BCC) is the most common skin cancer worldwide,with incidence rates continuing to increase.Ultraviolet radiation is the major environmental risk factor and dysregulation of the Hedgehog (Hh) signaling pathway has been identified in most BCCs.The treatment of locally advancedand metastatic BBCs is still a challenge and requires a better animal model than the widely used rodents for drug development and testing.Chinese tree shrews (Tupaia belangeri chinensis) are closely related to primates,bearing many physiological and biochemical advantages over rodents for characterizing human diseases.Here,we successfully established a Chinese tree shrew BCC model by infecting tail skins with lentiviral SmoA1,an active form of Smoothened (Smo) used to constitutively activate the Hh signaling pathway.The pathological characteristics were verified by immunohistochemical analysis.Interestingly,BCC progress was greatly enhanced by the combined usage of lentiviral SmoA1 and shRNA targeting Chinese tree shrew p53.This work provides a useful animal model for further BCC studies and future drug discoveries.     

Positively selected genes of the Chinese tree shrew (Tupaia belangeri chinensis) locomotion system

While the recent release of the Chinese tree shrew(Tupaia belangeri chinensis) genome has made the tree shrew an increasingly viable experimental animal model for biomedical research, further study of the genome may facilitate new insights into the applicability of this model. For example, though the tree shrew has a rapid rate of speed and strong jumping ability, there are limited studies on its locomotion ability. In this study we used the available Chinese tree shrew genome information and compared the evolutionary pattern of 407 locomotion system related orthologs among five mammals(human, rhesus monkey, mouse, rat and dog) and the Chinese tree shrew. Our analyses identified 29 genes with significantly high ω(Ka/Ks ratio) values and 48 amino acid sites in 14 genes showed significant evidence of positive selection in the Chinese tree shrew. Some of these positively selected genes, e.g. HOXA6(homeobox A6) and AVP(arginine vasopressin), play important roles in muscle contraction or skeletal morphogenesis. These results provide important clues in understanding the genetic bases of locomotor adaptation in the Chinese tree shrew.     

Characterization of 12 polymorphic microsatellite markers in the Chinese tree shrew (Tupaia belangeri chinensis)

The Chinese tree shrew (Tupaia belangeri chinensis) is a small experimental animal with a close affinity to primates. This species has long been proposed to be an alternative experimental animal to primates in biomedical research. Despite decades of study, there is no pure breed for this animal, and the overall genetic diversity of wild tree shrews remains largely unknown. In order to obtain a set of genetic markers for evaluating the genetic diversity of tree shrew wild populations and tracing the lineages in inbreeding populations, we developed 12 polymorphic microsatellite markers from the genomic DNA of the tree shrew. An analysis of a wild population of 117 individuals collected from the suburb of Kunming, China, showed that these loci exhibited a highly expected heterozygosity (0.616). These 12 microsatellites were sufficient for individual identification and parentage analysis. The microsatellite markers developed in this study will be of use in evaluating genetic diversity and lineage tracing for the tree shrew.     

Tree shrew (Tupaia belangeri) as a novel laboratory disease animal model

The tree shrew (Tupaia belangen) is a promising laboratory animal that possesses a closer genetic relationship to primates than to rodents.In addition,advantages such as small size,easy breeding,and rapid reproduction make the tree shrew an ideal subject for the study of human disease.Numerous tree shrew disease models have been generated in biological and medical studies in recent years.Here we summarize current tree shrew disease models,including models of infectious diseases,cancers,depressive disorders,drug addiction,myopia,metabolic diseases,and immune-related diseases.With the success of tree shrew transgenic technology,this species will be increasingly used in biological and medical studies in the future.     

中缅树鼩精子形态特征及冷冻损伤

树鼩作为一种新型的、接近灵长类的实验动物,在医学生物学上的应用受到越来越多的重视。精子的结构特性研究及冷冻后结构的完整性分析是精子生物学的主要内容,也有助于树鼩的实验室快速繁殖。该研究采用人工饲养的中缅树鼩(Tupaia belangeri chinensis),结果显示其睾丸占总体重的(1.05±0.07)%,总体积为(1.12±0.10)mL。附睾尾及输精管精子总量估计在2.2×107～8.8×107,其运动度和顶体完整率分别为(68.8±3.9)%和(90.0±2.1)%。利用扫描电子显微镜和透射电子显微镜对树鼩附睾精子的超微结构进行的观察和分析显示精子头部呈圆形或卵圆形;头部长度、宽度平均分别为6.65和5.82μm;精子尾部中段、主段、尾段和精子总长度平均分别为13.39、52.35、65.74和73.05μm;尾部中段的线粒体螺旋数量为48个,其轴丝结构为典型的"9+9+2"结构。冷冻解冻后的精子主要表现在顶体与质膜不完整、精子断裂、尾部扭曲和膨大。上述结果提示树鼩精子与其他哺乳动物精子的结构特征相似,但是精子大小和线粒体螺旋数目有明显的差别,且超微结构改变仍是冷冻精子运动和受精能力下降的主要原因。     

Proteomic characteristics of the liver and skeletal muscle in the Chinese tree shrew (Tupaia belangeri chinensis)

Valid animal models are useful for studying the pathophysiology of specific disorders, such as neural disease, diabetes and cancer. Previous molecular phylogeny studies indicate that the tree shrew is in the same order as (or a close sister to) primates, and thus may be an ideal model in which to study human disease. In this study, the proteome of liver and muscle tissue in tree the shrew was identified by combining peptide fractionation and LC-MS/MS identification. In total, 2146 proteins were detected, including 1759 proteins in liver samples and 885 proteins in skeletal muscle samples from the tree shrew. Further sub-source analysis revealed that nearly half of the identified proteins (846 proteins and 418 proteins) were derived from human database. In this study, we are the first to describe the characteristics of the proteome from the liver and skeletal muscle of the tree shrew. Phylogenetic tree analysis based on these proteomic data showed that the tree shrew is closer to primates (human) than to glires (the mouse and rat).