杂色山雀双亲差异性育雏策略

社会性单配制鸟类的配偶双方在抚育子代时常存在性别差异,不同鸟种的雌雄双亲往往采取不同的育雏策略。以杂色山雀(Sittiparus varius)为研究对象,2017年3—7月对繁殖巢箱进行录像监测,记录杂色山雀育雏期亲代投入情况。分析结果显示:1)双亲递食率在育雏前期(4—6日龄)无显著差异,而育雏后期(10—12日龄)雌性的递食率显著高于雄性。2)雌性亲鸟后期递食率较育雏前期显著增加;而雄性亲鸟育雏前期和后期递食率无显著差异。3)雌性递食率与自身喙宽呈极显著正相关,雄性递食率与双亲体征参数均无相关关系。总的来说,在育雏阶段,杂色山雀雌性亲鸟的递食率随着雏鸟的需求和自身身体质量发生调整,雌性在育雏后期递食率显著升高,而雄性亲鸟递食率无变化,这可能与育雏期双亲投入分工不同有关。     

繁殖期杂色山雀应激水平的皮质酮浓度 与繁殖投入的关系

皮质酮是鸟类重要的糖皮质激素,在其适应环境变化及压力应激反应中起重要的调节作用。非应激状态时,鸟类血浆皮质酮浓度处于基线水平,当鸟类面对应激刺激时,血浆皮质酮浓度迅速升高,应激水平的皮质酮对鸟类个体生存至关重要。然而,目前繁殖季鸟类血浆应激水平的皮质酮浓度变化及其与繁殖投入关系的研究结果存在种间差异,仍需在不同的物种中进行实验研究。本研究分析了繁殖季杂色山雀（Sittiparus varius）血浆应激水平的皮质酮浓度在繁殖阶段的变化,及育雏期亲鸟血浆应激水平的皮质酮浓度与繁殖参数和亲鸟育雏投入的关系。结果显示,与求偶期相比,育雏期杂色山雀亲鸟血浆应激水平的皮质酮浓度极显著升高（P < 0.001）,雌性与雄性亲鸟之间无显著性差异（P > 0.05）;雌性与雄性亲鸟血浆应激水平的皮质酮浓度与繁殖参数、亲鸟递食投入、巢防卫行为均无显著相关性（P > 0.05）。     

杂色山雀的繁殖成功率

2004～2006年的3～7月,在辽宁省白石砬子国家级自然保护区,对杂色山雀(Parus varius)的繁殖及繁殖成功率进行了初步研究。结果显示,杂色山雀主要营巢于海拔400～900m的阔叶杂木林、针叶林及林缘地带;繁殖期在3～7月,其洞巢种类多样,筑巢期约15d;巢为碗状,巢结构的2/3由苔藓构成;窝卵数为6～8枚,平均(6·92±0·92)枚(n=13);雌鸟单独孵卵,孵化期为(14·00±0·00)d(n=10);育雏由雌雄鸟共同承担,育雏期为(17·50±0·58)d(n=4)。杂色山雀繁殖成功率为50·95%,繁殖力为2·22。人为干扰是造成卵和雏鸟损失的主要原因,占总损失的74·19%。     

年龄对朱鹮繁殖成功率的影响

本文对陕西洋县16年间朱鹮(Nipponia nippon)年龄对繁殖成功率的影响进行了研究,结果表明:朱鹮首次参加繁殖的平均年龄为3.89±1.40年(n=73),雌雄分别为3.64±1.36年(n=37)和4.17±1.47年(n=36),差异不显著。2-3龄亲鸟的平均窝卵数、孵化率和出飞率显著低于4-10龄的繁殖个体;>10龄繁殖个体的产卵数和卵的受精率显著降低,但雏鸟成活率较高。三个年龄组之间的繁殖成功率无显著差异(F2,146=1.963,P=0.144)。随着雌雄亲鸟年龄的增长,幼鸟的出飞率显著增加。刚参加繁殖的2龄雌性产卵数很低(2.63±0.74,n=8),至5龄时达到最大值(3.2±0.92,n=10)。6-9龄的雌雄个体产卵数量处于相对的低峰,10龄左右有所恢复(3.0±0,n=3),此后维持一个相对较低的水平(2.55±0.99,n=20)。刚参加繁殖的雄性朱鹮(2年)形成的配对卵的孵化率较低(0.67±0.29,n=3),但在第二年迅速达到高峰,而且能维持5-6年的时间。9-10年时略有下降(0.88±0.18,n=2;0.93±0.17,n=3),10年以后维持在一个较低的水平上(0.56±0.51,n=19)。     

人工巢箱中大山雀和褐头山雀的繁殖比较

2009年3-7月,在北京小龙门森林公园悬挂人工巢箱,对大山雀(Parus major)和褐头山雀(P.montanus;)的繁殖进行比较研究.野外共悬挂100个巢箱,其中19巢(19.0%)被大山雀、11巢(11.0%)被褐头山雀进驻,总利用率为30.0%.同域繁殖的大山雀和褐头山雀在窝卵数、孵化期上有极显著差异(P＜0.01),其中大山雀的窝卵数(8.21枚±0.25枚,n=19)极显著大于褐头山雀(6.18枚±0.23枚,n=11),而褐头山雀的孵化期(14.22d±0.44d,n=10)极显著长于大山雀(13.17 d±O.83 d,n=12).两者在卵重、卵大小、出雏数、雏鸟出飞数上无显著差异(P＞0.05).大山雀的繁殖成功率(27.0%)和营巢成效(63.2%)均显著低于褐头山雀(54.5%和100%)(P＜0.01).表明大山雀可能采取高产卵数、低存活率的繁殖对策,而褐头山雀的繁殖策略则可能为低产卵数、高存活率.     

杂色山雀(Parus varius)亲代喂食与子代乞食间的行为交流

在育雏期,晚成鸟的子代一般都是由双亲共同来抚育,子代为了更好地存活,会用自己的方式竞争获得更多的食物和更好的生存空间,同时亲代也会通过子代的乞食信号来分配食物。2011年3月-7月采用针孔摄像技术录制了杂色山雀(Parus varius)育雏期巢内亲代与子代间的行为交流,统计了亲鸟站位、雏鸟站位、雏鸟乞食强度及亲鸟的喂食情况等数据。分析结果表明：(1)雌雄亲鸟在巢中的站位各有特点：雄鸟在整个育雏期都喜欢站在距离巢口较近的位置;雌鸟站位不太固定,前期离巢口相对较远,中期和后期离巢口相对较近;(2)雏鸟离亲鸟越近,乞食强度越大,获得食物的机会就越多;(3)杂色山雀主要是雌鸟担任育雏任务,喂食频率远大于雄鸟;(4)育雏期的不同阶段雏鸟乞食强度、亲鸟喂食频率变化很大：中期雏鸟乞食强度最大,亲鸟喂食频率最高,后期雏鸟乞食强度最弱;(5)整个育雏期雌性亲本没表现出明显的偏爱行为,但雄性亲本在中期表现出了偏爱大的雏鸟。     

大鵟繁殖期的行为及时间分配

2015年4～9月,采用焦点动物取样法,通过人工观察及监控设备记录,在青海省祁连县研究了2窝在人工巢中繁殖的大(鵟)(Buteo hemilasius)行为.构建了大(鵟)亲鸟及雏鸟在繁殖期的行为谱,将亲鸟繁殖期内的行为划分为12项30种,将雏鸟的行为划分为9项25种.研究发现,大(鵟)繁殖期开始于4月中下旬,持续至8月中旬结束,平均(112.0±2.0)d(n=2);将繁殖期划分为孵卵前期、孵卵期、育雏期及雏鸟成熟期.利用单因素方差分析(One-way ANOVA)比对了雌雄亲鸟之间,以及不同时期间亲鸟、雏鸟的行为时间分配.结果显示,(1)雌雄大(鵟)之间的行为时间分配在孵卵前期及孵卵期差异不显著(P＞0.05),在育雏期及雏鸟成熟期差异显著(P＜0.05).在这两个时期,雌性栖停行为所占比例显著高于雄性(P＜0.01),而捕食行为占比显著低于雄性(P＜ 0.01).(2)雌性大(鵟)行为时间分配在不同时期均变化显著(P＜ 0.05),雄性大(鵟)行为时间分配在育雏期与雏鸟成熟期间差异不显著,其余各个时期间差异显著(P＜ 0.05).(3)大(鵟)雏鸟行为时间分配在育雏期与成熟期之间差异显著(P＜0.05).     

大■繁殖期的行为及时间分配

2015年4~9月,采用焦点动物取样法,通过人工观察及监控设备记录,在青海省祁连县研究了2窝在人工巢中繁殖的大■(Buteo hemilasius)行为。构建了大■亲鸟及雏鸟在繁殖期的行为谱,将亲鸟繁殖期内的行为划分为12项30种,将雏鸟的行为划分为9项25种。研究发现,大■繁殖期开始于4月中下旬,持续至8月中旬结束,平均(112.0±2.0)d(n=2);将繁殖期划分为孵卵前期、孵卵期、育雏期及雏鸟成熟期。利用单因素方差分析(One-way ANOVA)比对了雌雄亲鸟之间,以及不同时期间亲鸟、雏鸟的行为时间分配。结果显示,(1)雌雄大■之间的行为时间分配在孵卵前期及孵卵期差异不显著(P0.05),在育雏期及雏鸟成熟期差异显著(P0.05)。在这两个时期,雌性栖停行为所占比例显著高于雄性(P0.01),而捕食行为占比显著低于雄性(P0.01)。(2)雌性大■行为时间分配在不同时期均变化显著(P0.05),雄性大■行为时间分配在育雏期与雏鸟成熟期间差异不显著,其余各个时期间差异显著(P0.05)。(3)大■雏鸟行为时间分配在育雏期与成熟期之间差异显著(P0.05)。     

杂色山雀亲代喂食与子代乞食间的行为

在育雏期,晚成鸟的子代一般都是由双亲共同来抚育,子代为了更好地存活,会用自己的方式竞争获得更多的食物和更好的生存空间,同时亲代也会根据子代的乞食信号来分配食物。2011年3～7月采用针孔摄像技术录制了杂色山雀(Parus varius)育雏期巢内亲代与子代间的行为,统计了亲鸟站位、雏鸟站位、雏鸟乞食强度及亲鸟的喂食情况等数据。分析结果表明:(1)雌雄亲鸟在巢中的站位各有特点,雄鸟在整个育雏期都喜欢站在距离巢口较近的位置;雌鸟站位不太固定,前期离巢口相对较远,中期和后期离巢口相对较近;(2)雏鸟离亲鸟越近,乞食强度越大,获得食物的机会就越多;离亲鸟越远的雏鸟越不爱乞食,所以站位对雏鸟的食物获得影响最大;(3)雌鸟承担主要的育雏任务,喂食频率远大于雄鸟;(4)育雏期的不同阶段雏鸟乞食强度、亲鸟喂食频率变化很大:中期雏鸟乞食强度最大,亲鸟喂食频率最高,后期雏鸟乞食强度最弱;(5)整个育雏期雌性亲本没有表现出明显的偏爱行为,但雄性亲本在中、后期更偏爱体型大的雏鸟。可见杂色山雀子代的行为和体型大小影响着亲代的食物分配,亲代也会根据雏鸟日龄调整站位和喂食行为。     

杂色山雀的繁殖生态

2004—2006年3—7月在辽宁省白石砬子国家级自然保护区对杂色山雀的繁殖生态进行了观察研究。结果表明:该鸟繁殖期为3—7月,筑巢地除了树洞之外,还见在墙缝、石缝、金腰燕旧巢及电柱孔洞中筑巢,筑巢主要由雌鸟完成,雄鸟从旁协助;产卵期为5～8d,日产1枚,窝卵数为(6.92±0.92)枚(n=13);产满窝卵数后即开始孵化;孵化由雌鸟单独完成,孵化期(14.00±0.00)d(n=10),坐巢时间(570.00±11.02)min.d-1(n=9)(不含夜间),平均坐巢时间(57.00±6.75)min.次-1(n=9),雄鸟担任警卫任务,孵化期较为敏感,受到干扰易弃巢;育雏期(17.50±0.58)d(n=4),由雌雄鸟共同喂雏,雏鸟出飞后先是在亲鸟的带领下在巢周活动,之后活动范围逐渐扩展,2～3d后基本离开巢区。     

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.