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1.
MicroRNAs (miRNAs) are known to play an important role in regulating the cell proliferation, differentiation and organogenesis. Abnormal expression of miRNAs is associated with increased risk for various diseases, such as neural tube defects (NTD), which is a severe developmental disease as the result of closing the neural tube incompletely or too early. The present review summarizes some enriched miRNAs in the brain of mammals and their spatial temporal feature, and tries to elaborate the relationship between the aberrant expression of miRNAs and the pathogenesis of NTD.  相似文献   
2.
为了明确哺乳类和鸟类宿主隐孢子虫能否交叉感染,分别从鸡、兔、小白鼠、鸭、鹌鹑分离到隐孢子虫进行交叉感染。结果,从鸡分离的隐孢子虫卵囊能感染鸭、鹌鹑、麻雀,而不能感染鸽、大白鼠、小白鼠、兔,从鸭分离的卵囊能感染鸡,从兔、小白鼠分离的卵囊不能感染鸡、鹌鹑,从鹌鹑分离的卵囊不能感染兔、大白鼠、小白鼠和鸡。提示隐孢子虫在宿主纲水平上有宿主特异性。  相似文献   
3.
The marine mammals of Saudi Arabia, Bahrain, Qatar and the United Arab Emirates (UAE) were censussed by three strip-transect aerial surveys. The Arabian Gulf supports a population of ca. 5800 dugongs (Dugong dugon), which is the largest known outside Australia. The most important habitats occur (1) around Murawah Island (UAE), (2) between Qatar and Bahrain and (3) between Qatar and the UAE. Surveys of the UAE were repeated 13 years apart. The two estimates of the dugong population were not significantly different, suggesting a stable population of ca. 3000 between 1986 and 1999. In the region between Kuwait and Oman, the Indian Ocean bottlenose dolphin (Tursiops aduncus) is the most common cetacean (71% of groups and individuals), followed by the Indo-Pacific humpback dolphin (Sousa chinensis; 27%) and finless porpoise (Neophocaena phocaenoides; 2%). The estimates of cetacean abundance in the UAE differed significantly between 1986 and 1999 and indicate a population decline of 71%. At least two die-offs of marine mammals occurred between these surveys. The countries of the southern Gulf are developed and affluent and are well positioned to take a lead in marine conservation in the region. A coordinated series of protected areas could greatly enhance the long-term prospects for marine mammals and other components of biodiversity in the region.  相似文献   
4.
On islands in the Gulf of California, many species and subspecies of rodents are relict species, restricted to the islands, and now considered extinct or verging on extinction. From 1991 to 1999, each island was surveyed and an average of 15 work-nights were spent on each island, for a total of 15,000 trap-nights. A Fourier series was used to estimate population density. Five native taxa are now considered extinct (Chaetodipus baileyi fornicatus, Peromyscus guardia mejiae, P. g. harbinsoni, P. pembertoni, and Neotoma bunkeri). Two species are at risk of extinction (Dipodomys insularis and Neotoma albigula varia). The most probable cause for extinction is the introduction of nonnative species, specifically cats. We believe that the most vulnerable rodent populations of the islands in the Gulf of California to non-native species are Neotoma lepida latirostra on Danzante island and Neotoma lepida abbreviata on San Francisco island, both in the state of Baja California Sur.  相似文献   
5.
哺乳动物体内的钙代谢通常包括钙平衡和钙稳态。钙平衡是指体内总钙含量保持相对恒定的状态,钙稳态则指细胞内外的钙离子浓度保持稳定。肾脏、肠道、骨骼及雌性动物乳腺是动物体钙代谢的主要器官,其中存在着许多精细而复杂的调控网络。妊娠期钙代谢紊乱会严重影响母畜及胎儿的营养健康,维持体内钙代谢稳态对围产期哺乳动物尤为重要。本文综合近年来国内外妊娠期哺乳动物钙代谢相关研究,从不同组织器官钙代谢情况及钙代谢过程中重要的调节因子的调控作用进行综述,旨在为妊娠期哺乳动物钙代谢调控相关研究提供思路。  相似文献   
6.
主要阐述了哺乳动物体细胞克隆技术及克隆胚发育机制的研究现状和研究进展,并着重强调了体细胞克隆中一些亟待解决的问题。  相似文献   
7.
2006年7月至200g年9月,采用样线调查法、铁日法和网捕法对金佛山自然保护区兽类资源进行了调查。结合文献资料和社区访谈结果,金佛山自然保护区目前已知兽类69种,隶属于8目24科56属。金佛山自然保护区珍稀保护兽类资源较丰富,有国家一级保护动物3种,二级保护动物11种;被列入《濒危野生动植物种国际贸易公约》(CITES)附录Ⅰ的有4种,附录Ⅱ的有7种,附录Ⅲ的有4种。从动物区系成分来看,南方类型49种,占总种数的71.01%;北方类型有11种,占总种数的15.94%;季风型和广泛分布型9种,占总种数的13.05%。  相似文献   
8.
The aim of the present study was to analyse the occurrence of chlamydiae in several mammalian host species. Clinical samples that previously tested positive in a Chlamydiaceae-specific real-time PCR were retested using six species-specific real-time PCR assays to identify the chlamydial species involved. Chlamydophila (Cp.) abortus was the agent most frequently found in cattle, sheep, horses, goats, and pigs. Detection in cattle of Cp. psittaci (11% of samples) and Chlamydia (C.) suis (9%), as well as Cp. psittaci in a goat sample was somewhat unexpected. DNA of two different chlamydiae was identified in 56 (12.7%) of 440 samples tested. Cp. felis was the predominant species found in cats, while in guinea pigs and rabbits only Cp. caviae was detected. Interestingly, the latter two pathogens were also identified in samples from dogs. The data show that mixed chlamydial infections are not rare and suggest an extended host range of individual species.  相似文献   
9.
哺乳动物精子超微结构研究进展   总被引:1,自引:0,他引:1  
精子超微结构研究是检验精液品质,揭示精子发生机制,开展受精生物学研究的一项重要内容。从哺乳动物的精子形态结构出发,综述了不同情况下精子变化的特征,论述了国内近些年来在哺乳动物精子超策结构上的一些研究进展,以及开展哺乳动物精子超微结构研究的意义。  相似文献   
10.
对哺乳动物生精细胞进行显微授精这一新型体外授精技术的研究现状、技术方法、细胞周期及调控、基因印迹及其运用前景进行较系统全面的概述,旨在促进我国同类研究的快速发展,使该项技术早日在我国畜牧业和濒危动物保护方面发挥重大作用。  相似文献   
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