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。     

麋鹿“妻妾”成群

在浅水和陆地的交汇处,一只雄性麋鹿头上顶着一对漂亮的角,体格健壮,威风凛凛,守护着几百平米范围里的雌鹿群。它不停地来回巡视着,驱逐试图进入自己领地的其他雄鹿,有时还能见到一头雌鹿用脸和头在雄鹿的身上亲昵摩擦着。每当炎热的夏季来临,这样的     

圈养雄性麋鹿血清睾酮和皮质醇含量在发情期的变化

2000年7-8月在北京麋鹿苑采集不同繁殖状态雄鹿（发情前3头、发情3头和发情后4头）血液样品,用放射免疫分析法测定血清睾酮和皮质醇含量。结果显示发情雄鹿的睾酮浓度显著高于发情前、后,而3种状态雄鹿的皮质醇浓度无差异,并且与睾酮浓度无关。本苑麋鹿睾酮水平的变化与同类野生动物一致。     

麋鹿发情期主要活动的时间分配及行为研究

本文报道麋鹿在白天主要处于休息状态,早晨、黄昏是它们的摄食时间;成年雌体中的各项活动频率未显示出有明显差异;但雄鹿与雌鹿之间在活动时间分配上有明显差异,而且,雄鹿中的统治者与被统治者之间也表现出有所不同。在攻击行为方面,群内表现出有不同的特权形式;而在交往行为中,发现较多的频次出现于相同性别、年龄和同一阶层中。     

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。     

发情期小灵猫行为的研究

本文对笼养小灵猫发情期的繁殖行为进行了观察。结果表明：小灵猫一年有两次发情期,绝大部分的小灵猫在春季（２－４月）发情,少数个体在秋季（８月底至９月）出现第２次发情。发情期雄性小灵猫频繁地发出求偶叫声和增加擦香次数。雄猫的擦香行为和求偶叫声可促使雌猫的发情,发情期一系列性行为对雌雄交配的成功与否有重要的意义。     

麋鹿人工授精技术初步研究

为了为麋鹿的人工繁殖提供理论基础,2007年7月～2009年6月对麋鹿人工授精技术进行了研究.2007年7月,对5只雄性麋鹿进行了6次电刺激采精试验,成功率100%(6/6),采得的精液品质优良,采精量为0.7～4.0 mL,平均采精量(1.7±1.3)mL,平均精子密度(14.25±2.88)亿/mL,精子活力为50%～80%.2007年,应用孕激素类药物(CIDR)对6只雌鹿进行同期发情处理,采用定时1次人工输精,鲜精输精6只,受胎1只,受胎率为16.7%;2008年,5只雌鹿发情采用雄鹿试情,冻精输精5只,受胎1只,受胎率20%.这两只麋鹿孕期分别为288 d和268 d.     

麋鹿的配偶制度、交配计策与有效种群

模拟分析了繁殖群体大小、繁殖偏倚和占群优势雄性数目对麋鹿的有效种群大小的影响.发现麋鹿占群优势雄性数目越少,其有效种群越小.麋鹿的繁殖计策对遗传多样性的保存的作用十分有限.雄性繁殖后代数目的方差越大,繁殖群体的有效群体越小.近交系数在封闭繁育种群中会上升.麋鹿有效种群越大,近交系数上升越快.根据分析结果,为了保存麋鹿种群中现有的遗传多样性,应当采取如下措施：（1）建立麋鹿繁殖群的遗传谱系档案,检测参加繁殖的麋鹿的遗传结构,记录繁殖的麋鹿的谱系;（2）每个麋鹿繁育基地应建立两个以上的繁殖群,组成繁殖群时,应隔离亲缘关系近的繁殖公鹿和雌鹿;（3）由于麋鹿的繁殖系统是后宫制,组成的每个麋鹿繁殖群不宜太大,繁殖公鹿和雌鹿数目应尽可能相等;（4）组成迁地保护的奠基群体时,根据应根据麋鹿繁殖群的遗传谱系档案注意保留原种群的遗传多样性以及奠基群体的遗传代表性.     

四川梅花鹿繁殖行为

2006年4—12月和2007年3—11月在四川省铁布自然保护区观察和统计了野生梅花鹿的繁殖行为,包括发情交配、产仔、发情吼叫、爬跨及其昼夜节律行为等。结果表明,四川梅花鹿为季节性发情动物,发情交配行为发生在9月上旬至12月中旬,集中在10—11月(占(86.99±3.24)%)。四川梅花鹿发情交配日期最早见于9月8日,最晚为12月16日,跨度约90—100 d(±6 d,n=90)。雌鹿交配日期与其繁殖经历具有低度正相关性(Kendall's tau-b和Spearman's rho,0.3r0.5,P0.05),成体雌鹿交配日期稍微早于初次配种雌鹿。雄鹿发情吼叫和爬跨行为具有明显的昼夜节律性,各有2个高峰期(05:00—08:00和18:00—21:00),夜间有小节律的发情吼叫和爬跨时期。U-test检验表明发情吼叫频次和爬跨频率在昼夜间有极显著差异(P0.01)。雄鹿吼叫行为与其交配行为具有高度正相关性(Kendall's tau-b和Spearman's rho,0.8r1.0,P0.05),主雄、次雄和群外单身雄鹿的昼夜吼叫次数有极显著差异(P0.01)。雌鹿产仔期从4月下旬开始到7月下旬结束,集中在5—6月(占(91.51±4.96)%),产仔日期最早见于4月29日,最晚为7月28日,跨度约80—90 d(±5 d,n=130)。梅花鹿产仔日期与其分娩经历具有低度正相关性(Kendall's tau-b和Spearman's rho,0.3r0.5,P0.05),成体雌鹿产仔日期早于初次繁殖雌鹿。雌鹿每胎产1—2个幼仔,单双胎率分别为98.86%(±6.96%,n=129)和1.01%(±0.07%,n=1)。妊娠期和哺乳期梅花鹿采食行为分配占较大比率,其次是卧息和移动,哺乳期采食行为分配低于妊娠期,这与妊娠期正逢冬季,食物资源相对匮乏有关,而哺乳期恰逢夏季,植物生长旺盛,食物资源相对丰富。     

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.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.     

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.     

肝癌中HBV和HCV基因和抗原的分布及意义

采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细