雄性麋鹿的交配机会、社会等级和皮质醇水平

我们在北京麋鹿苑研究了发情期雄性麋鹿的社会行为、社会等级和血清皮质醇水平,并分析了三者间的相互关系。按照雄性麋鹿的行为,将雄性麋鹿分为优势群和从属群。优势群包括群主和挑战者,从属群包括单身汉和被淘汰群主。使用SJ—Ⅰ型事件记录器进行常规行为取样,用放射免疫分析法测定血清皮质醇含量。发现：(1)优势雄鹿的发情行为频次明显高于从属雄鹿;(2)攻击行为的发生频次在两组间无显著差异;(3)血清皮质醇含量在两组间也无显著差异。由此我们认为,发情期雄性麋鹿的社会等级序位影响许多行为的表达,优势雄鹿成功交配的机会比从属雄鹿多。而攻击行为和肾上腺皮质醇的分泌与社群等级无明显相关,可能是麋鹿在圈养状态下的一种适应策略,这将有利于缓解发情期雄鹿的紧张,从而允许更多的能量投放在发情交配上。     

雄性麋鹿的吼叫行为、序位等级与成功繁殖

为探讨雄性麋鹿（Elaphurus davidianus）的吼叫行为与序位等级的关系,以及这种关系在成功繁殖中的作用。2000年7－8月,在北京麋鹿苑选定12头成体雄鹿,用目标取样法观察记录每头鹿的吼叫、圈群和交配行为的发生频次。用有效比值[被雌鹿接受的频次／雄鹿圈群（或交配）的总频次]来衡量雄鹿圈群行为（或交配行为）的有效性。依据雄鹿在发情期的表现状态,把雄鹿归为3类：占有雌鹿群的“群主”（4头）、未占有雌鹿群而挑战“群主”的“挑战者”（5头）和远离繁殖群的“单身汉”（3头）。不同序位等级雄鹿的吼叫频次、圈群（或交配）行为频次、圈群行为（或交配行为）的有效值存在显著差异（P＜0.05）。对吼叫行为的分析表明：“群主”吼叫频次最高,“单身汉”吼叫频次最低。“群主”的有效值最高,“单身汉”的有效值最低。据此认为雄性麋鹿的吼叫行为与其序位等级密切相关,而序位等级又决定了雄鹿参与繁殖的机会。此外,还记录到占群雄鹿的警戒吼叫,这是对Wemmer et al.(1983)警戒吼叫行为仅见于雌鹿的观察结果的补充。     

不同密度下和不同发情期时段中雄性麋鹿的繁殖计策

从1998年到2001年,我们研究了密度、发情期与雄性麋鹿繁殖计策的关系。我们选择了江苏大丰麋鹿保护区的两个麋鹿群体和北京麋鹿苑的一个麋鹿群体,观察记录了发情期前期、中期和后期中实验麋鹿种群参数、围栏大小、群体中雄鹿的繁殖计策、群主变更情况、后宫数目以及后宫雌鹿数。尽管不同种群和不同发情期的雄鹿繁殖计策有差异,但是各个群体中雄性麋鹿都有占群、偷袭交配和求偶集会3种繁殖计策。利用因子分析提取了两个主成分:主成分1主要代表实验围栏、麋鹿存栏数和密度等因子的影响,主成分2主要代表发情期时段因子的影响。这两个主成分解释了全部因素效应的90.72%。用Spearman相关分析发现,占群计策与主成分2呈极显著负相关,求偶集会计策与主成分1呈显著正相关,最大后宫雌鹿个体数与主成分1极显著正相关,而偷袭交配计策和后宫数目与主成分1和2均无显著相关。据此推测,占群和求偶集会繁殖计策分别受密度和发情期时段的影响,而偷袭交配行为对密度和发情期时段不敏感。我们还探讨了麋鹿发情行为计策的环境适应性,从行为学角度为麋鹿保护提供了新思路。     

半野生麋鹿集群行为的初步研究

麋鹿在半野生状态下喜集群活动,不同月份集群的大小以及各种组群出现的频率均有所变化。半野生麋鹿有５种组群类型：雄鹿群、母仔群、混合群、雄仔群和仔鹿群。其中混合群出现频率最高,集群最大,是其主要的组群类型,雄鹿群最为稳定,母仔群中采食组群所占比例和组群大小都大于非采食活动的组群,雄仔群和仔鹿群出现频次较少。麋鹿发情期与非发情的集群有明显差异,不同生境内的集群也有所不同。     

"占群"还是"挑战"?不同时间限制条件下麋鹿个体的交配计策

在麋鹿的发情交配季节 ,雄性麋鹿可区分为 3种类型 :“群主”、“挑战者”和“单身汉”。“群主”是一头圈占并控制雌鹿活动的优势雄性。“挑战者”不占有雌性繁殖群 ,但在发情场附近地点展示炫耀。当雌性繁殖群的雌鹿外出采食靠近“挑战者”的展示炫耀地点时 ,“挑战者”会积极地寻求机会与之交配。“单身汉”在繁殖季节不表现发情行为。他们像非繁殖季节一样采食 ,采食后蹲在水塘中休息。我们对何种因素决定麋鹿个体的发情交配计策感兴趣。 1996至 1998年夏天 ,我们在北京麋鹿苑观察麋鹿发情交配行为以分析导致这些行为差异的原因。结果发现 ,“群主”、“挑战者”和“单身汉”用于维持生命的时间预算与用于发情的时间预算成反比 ,并且 ,“群主”、“挑战者”和“单身汉”用于维持生命的时间预算与用于发情的时间预算差异显著。“群主”的绝大部分时间用于发情占群 ,而用于采食、饮水的时间很少 ,所以 ,“群主”在发情期间基本上处于禁食状态 ,靠消耗体内脂肪维持生命。“单身汉”则相反 ,绝大部分时间用于采食、休息和反刍 ,基本上没有发情行为。“挑战者”在发情行为与维持生命行为之间的时间则居于“群主”与“单身汉”之间。交配次数是偏态分布的 ,与雄性发情时间呈正比。“群主”的交配概率最高     

麋鹿繁殖行为和粪样激素水平变化的关系

１９９７年７－９月和１９９８年３－７月间,在江苏大麋鹿保护区共观察到麋鹿的２７种繁殖行为,雄鹿有１７种,雌鹿有１０种,在１９９８年３－７月间,利用放射免疫分析法（ＲＩＡ）测定了鹿麋样中的性激素水平,包括雄鹿的睾酮,雌鹿的酮,雌鹿的孕酮、雌二醇和雌三醇。实验结果表明：１许多繁殖行为的发生频次和持续时间表现出明显的季节变化（Ｐ〈０．０５）,如雄鹿的求偶行为、标记行为和性行为及雌鹿的性行为等在发情期有一     

麇鹿幼仔的活动同步性与同性聚群倾向

哺乳动物幼体从出生到性成熟这段时间存在生理和行为上的巨大变化。麋鹿幼仔出生1周内,与成鹿和其它仔鹿呈隔离状态,且藏卧于隐蔽处,母鹿哺乳是引起幼仔活动的主要因素。本文旨在探讨麋鹿雌雄幼仔之间的聚群倾向和活动同步性指数。现报道如下。1　材料与方法1 1　研究地点和对象本研究在北京麋鹿苑内进行。麋鹿苑面积60hm2,1999年有麋鹿近160头。植被优势种类为蟋蟀草(Eleusineindica),画眉草(Eragrostiscilia nensis),马塘(Digitariasangunalis)和狗尾草(Se tariaviridis)等。年均气温13 1℃,1月平均气温-3 4℃,7月平均气温26 4℃。年…     

雄性麋鹿胆量和侵犯耦合与等级序位变化的关系

发情期的雄性麋鹿根据序位分为群主、挑战者和单身汉3个等级,序位变化是雄性麋鹿应对环境压力的直 观体现。本文利用胆量和侵犯2个行为指标在麋鹿生活史不同阶段的耦合强弱,来解释幼体时麋鹿序位发育、亚 成体时雄性序位定型及发情期时挑战者对群体序位的扰动。行为取样采用焦点取样法和扫描取样法相结合;分 析个体间行为样本流的非同步化水平,以同类型行为中较早发生、同步化率较低的判断为胆大;侵犯则结合攻 击行为和取胜指数来判定;粪样睾酮水平测定采用放射免疫分析法。结果显示雄性麋鹿幼体胆量和侵犯耦合与 等级序位呈负相关(r=-0.111 8,P=0.018 3);成体胆量和侵犯耦合与等级序位的波动呈正相关(r=0.917 9,P= 0.002 6)。从亚成体到成体:4头雄性麋鹿序位上升(胆量和侵犯耦合r=0.852 3,P=0.000 3),其中1头成为鹿 王;4头序位未发生改变(胆量和侵犯耦合r=0.482 9,P=0.006 3);3头序位下降(胆量和侵犯耦合r=0.251 7, P=0.003 5)。雄性麋鹿幼体睾酮水平与等级序位呈正相关(r=0.860 7,P=0.005 5);亚成体睾酮水平与等级序 位呈正相关(r=0.845 7,P=0.004 4);成体睾酮水平与等级序位呈正相关(r=0.954 6,P=0.001 8)。结果表明雄 性麋鹿发情期胆量和侵犯耦合强度与等级序位波动呈正相关;等级序位上升与睾酮水平升高有关。     

半野生糜鹿集群行为的初步研究

糜鹿在半野生状态下喜集群括动,不同月份集群的大小以及各种组群出现的频率均有所变化。半野生糜鹿有5种组群类型：雄鹿群、母仔群、混合群、雄仔群和仔鹿群。其中混合群出现频率最高,集群最大,是其主要的组群类型,雄鹿群最为稳定,母仔群中采食组群所占比例和组群大小都大于非采食括动的组群,雄仔群和仔鹿群出现频次较少。麋鹿发情期与非发情的集群有明显差异,不同生境内的集群也有所不同。     

大熊猫粪便样本处理与激素萃取方法比较

通过测定圈养动物粪便中的激素水平,监测其发情与怀孕状态和评估其福利状况是目前普遍采用的一种实验手段。然而,现有研究对于圈养野生动物粪便样本的处理及其激素萃取方法存在很大分歧,研究结果也不尽一致。本研究采集了10只(雌∶雄=1∶1)圈养大熊猫(Ailuropoda melanoleuca)的粪便样本,分别采用冷冻干燥-研筛法和冷冻干燥-粉碎法处理粪便样本,然后分别使用80%甲醇、90%乙醇和95%乙醇3种萃取剂进行激素萃取,最后比较2种粪便处理方法和3种溶剂萃取方法所获得的粪便样本中孕酮、雌二醇、睾酮和皮质醇的浓度。结果表明,冷冻干燥-研筛法结合80%甲醇溶液萃取处理的样本中雌二醇和孕酮检测值最高,冷冻干燥-粉碎法结合80%甲醇溶液萃取处理的样本中睾酮检测值最高。冷冻干燥-粉碎法结合90%乙醇溶液萃取处理的样本与冷冻干燥-研筛法结合80%甲醇溶液萃取处理的样本中皮质醇检测值更高,且2种方法的检测结果差异不显著。综合粪便处理难易程度和萃取溶剂性质,建议雌二醇、孕酮和睾酮激素检测根据最高检测浓度的方法进行粪便前处理,皮质醇激素检测使用冷冻干燥-粉碎法结合90%乙醇溶液萃取方法进行粪便前处理。...     

A Unique Protease Cleavage Site Predicted in the Spike Protein of the Novel Pneumonia Coronavirus (2019-nCoV) Potentially Related to Viral Transmissibility

正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.     

Comparative morphology of the carpel in the Liliaceae: Hewardieae, Petrosavieae, and Tricyrteae

The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.     

Enterovirus 71 3C proteolytically processes the histone H3 N-terminal tail during infection

Highlights
1. The N-terminal tail of histone H3 is specifically cleaved during EV71 infection.
2. Viral protease 3C is identified as a protease responsible for proteolytically processing the N-terminal H3 tail.
3. Our finding reveals a new epigenetic regulatory mechanism for Enterovirus 71 in virus-host interactions.     

Detection of EBV and HHV6 in the Brain Tissue of Patients with Rasmussen’s Encephalitis

Rasmussen’s encephalitis (RE) is a rare pediatric neurological disorder, and the exact etiology is not clear. Viral infection may be involved in the pathogenesis of RE, but conflicting results have reported. In this study, we evaluated the expression of both Epstein-Barr virus (EBV) and human herpes virus (HHV) 6 antigens in brain sections from 30 patients with RE and 16 control individuals by immunohistochemistry. In the RE group, EBV and HHV6 antigens were detected in 56.7% (17/30) and 50% (15/30) of individuals, respectively. In contrast, no detectable EBV and HHV6 antigen expression was found in brain tissues of the control group. The co-expression of EBV and HHV6 was detected in 20.0% (6/30) of individuals. In particular, a 4-year-old boy had a typical clinical course, including a medical history of viral encephalitis, intractable epilepsy, and hemispheric atrophy. The co-expression of EBV and HHV6 was detected in neurons and astrocytes in the brain tissue, accompanied by a high frequency of CD8⁺ T cells. Our results suggest that EBV and HHV6 infection and the activation of CD8⁺ T cells are involved in the pathogenesis of RE.     

Perinatal Vertical Transmission of Chikungunya Virus in Ruili,a Town on the Border between China and Myanmar

正Dear Editor,Chikungunya virus (CHIKV), an arbovirus in the family of Togaviridae, genus Alphavirus, is transmitted by the A.aegyptii or A. albopictus mosquito, and causes disease in humans characterized by fever, rash, and arthralgia (Silva and Dermody 2017; Suhrbier 2019). It was first reported in 1953 in Tanzania, and caused only a few outbreaks and sporadic cases in Africa and Asia in last century. However, in the epidemic in 2004, CHIKV acquired mutations that conferred enhanced transmission by the A. albopictus mosquito(Schuffenecker et al. 2006). Since then, it has successively caused outbreaks in Africa, the Indian Ocean, South East Asia, the South America, and Europe (Zeller et al. 2016).     

Development of a Novel Reverse Transcription Loop-Mediated Isothermal Amplification Method for Rapid Detection of SARS-CoV-2

In conclusion, the novel visual RT-LAMP assay is a simple, rapid, and sensitive approach for detection of SARS-CoV-2, and it is ready for application in primary care and community hospitals or health care centers, and even patients' own houses in response to the current SARS-CoV-2 epidemic because the assay does not require sophisticated equipment and skilled personnel. Furthermore, it is also ready to be used in fields for screening samples from wild animals and environments to facilitate the identification of potential intermediate hosts that mediate the cross-species transmission of SARS-CoV-2 from bats to humans.