小气候对东北林蛙生长发育和繁殖的影响

于2009年5月—2010年5月,通过分组实验,研究了在大棚增温环境和围栏常温模拟林下环境条件下东北林蛙(Rana dybowskii)的生长发育情况。结果表明:与围栏常温模拟林下条件相比,大棚圈舍内平均气温、地温和湿度显著升高,有效积温增加;林蛙发育历期缩短,性成熟提前,二龄雌蛙性成熟比例增加,大棚圈舍的雌蛙的繁殖率为93.1%,围栏圈舍雌蛙的繁殖率为76.0%;在大棚中林蛙生长速度加快,饲养的一、二龄林蛙体重分别达到(6.30±2.62)g和(36.55±11.79)g,较围栏中体重提高了85.5%和56.6%;在大棚里林蛙出蛰时间、进食时间提前,停食时间、入蛰时间延后,生长期间延长,每窝平均产卵量增加,林蛙体重与产卵量呈显著的正相关(r=0.921,P<0.01)。     

放牧对若尔盖高原湿地CH4排放的影响

湿地是大气甲烷(CH_4)的主要排放源,而有关放牧对湿地CH_4排放的影响特征仍未得到足够的报道。因此,通过静态箱法,研究了放牧对四川省若尔盖高原湿地CH_4排放的影响,CH_4气体通过快速温室气体分析仪测量。结果表明:放牧样地和围栏内样地生长季CH_4排放量为(31.32±19.57)g/m~2和(30.31±23.46)g/m~2,它们之间无差异显著;但是集中放牧期间(7—9月),放牧样地(21.01±12.35)g/m~2较围栏内样地显著增加了CH_4排放量为54.3%。2014年生长季期间通过刈割植物模拟放牧表明两种刈割强度CH_4排放量为(5.01±5.37)g/m~2和(4.69±5.99)g/m~2,较未刈割样地(1.15±1.89)g/m~2增加了335.9%和308.0%,其原因可能是放牧或者刈割减少地表植物生物量,降低植物高度,缩短了CH_4排放的路径距离。该结果可为我国高原湿地保护与管理决策提供基础数据支撑。     

东北林蛙发育早期TLR2的表达及免疫应答特征

旨在研究东北林蛙发育早期TLR2的表达特征及其针对不同PAMPs的免疫应答特征。免疫组化染色及RT-PCR对11期至42期东北林蛙TLR2进行定位和定量检测;29期蝌蚪0.5μg/m L的LTA,LPS,Zymo A,Poly I∶C急性腹腔注射,RT-PCR检测24 h内TLR2 m RNA相对表达量变化。结果显示,TLR2在东北林蛙发育早期的组织中分布广泛,11期TLR2 m RNA相对表达量0.187±0.021,25期升至0.373±0.031后,42期降至0.170±0.020。24 h内未检测到LPS组和Zymo A组TLR2 m RNA相对表达量显著性变化(P0.05),LTA组在4 h与12 h出现两次极显著性升高(P0.01);Poly I∶C组于8 h至峰值(P0.01)。东北林蛙发育早期TLR2的时空表达特征与其发育阶段的生境变化相适应,29期东北林蛙的TLR2对4种PAMPs识别和应答兼具了鱼类和哺乳动物的特征,体现了免疫系统在进化上的演变。     

围栏条件下花鼠找寻种子的途径和方式

2009年8月和2010年8月,在黑龙江省带岭区东方红林场半天然围栏内研究了花鼠(Eutamias sibiricus)对地表放置和埋藏种子的发现过程,摸清围栏条件下花鼠找寻种子信号的途径和方式.实验步骤如下:第1天在花鼠巢区对角每释放点地表放置1粒标记种子,共30粒;第2天在巢区对角每释放点埋藏1粒标记种子,共30粒...     

密度对中国林蛙蝌蚪生长发育的影响

将中国林蛙（Rana chensinensis）蝌蚪分别饲养在40只／L、80只／L、120只／L、160只／L、200只／L和240只／L6个不同的密度条件下,通过定时定量喂食及测量其全长、尾长、体宽、体重和死亡率的变化,分析密度对中国林蛙蝌蚪生长发育的影响。实验结果表明：（1）饲养密度和生长发育时间及两者的交互作用对中国林蛙蝌蚪的生长发育影响都极其显著;（2）在40只／L的密度下,中国林蛙蝌蚪的全长、尾长、体宽、体重的增长速率最快,在240只／L的密度下,中国林蛙蝌蚪的全长、尾长、体宽、体重的增长速率最慢;（3）在相同时间内,40只／L的密度条件下中国林蛙蝌蚪的存活率最高,在240只／L的密度条件下中国林蛙蝌蚪的存活率最低;（4）中国林蛙蝌蚪的生长发育速度随饲养密度的升高而减慢。     

短期围栏封育对荒漠草原沙化灰钙土有机碳组分及物理稳定性的影响

以宁夏盐池县荒漠草原5年围栏封育草地(围栏内)和自由放牧草地(围栏外)为对象,分析0～ 40 cm土层土壤有机碳、易氧化有机碳和颗粒有机碳含量以及土壤粒径组成,研究围栏封育早期沙化灰钙土有机碳组分及物理稳定性的变化规律.结果表明:围栏内外土壤有机碳含量和颗粒组成差异不显著;围栏内外0～40 cm土层土壤有机碳含量平均为3.25g·kg-1,沙粒、粉粒、黏粒的相对比重平均为72％、16％、12％,土壤物理稳定性指数为1.30％～1.31％.土壤活性有机碳的显著变化集中在10～20 cm土层,围栏内易氧化有机碳含量达0.80 g·kg-1,显著高于围栏外的0.62 g·kg-1,围栏内颗粒有机碳的分配比例为50.9％,显著高于围栏外的31.7％.随土层深度的增加,围栏内0～ 40 cm土壤质地由沙性土向沙壤土转变,各层间土质差异显著,易氧化有机碳含量逐渐升高;而围栏外土壤质地的垂直变化相对平缓,基本为沙性土质.退化荒漠草原短期围栏封育条件下,沙化灰钙土土壤有机碳尚处于一个消耗与积累的平衡阶段,土壤质地状况相对稳定,土壤物理稳定性变化较小.10～20 cm土层土壤活性有机碳含量及其相对分配比例可作为围栏封育早期土壤质量变化的指示指标.     

自然孵育下大紫胸鹦鹉生长发育的观察

对自然孵育条件下3只大紫胸鹦鹉的生长发育情况进行了观察与分析,表明大紫胸鹦鹉的平均出壳重为(13.80±2.79)g,60日龄平均体重为(265.33±39.03)g。体重与日龄的关系为W=8.55 5.61×D(0～50日龄);出壳时嘴峰短于嘴裂,45日龄时嘴峰长度超过嘴裂,60日龄时嘴峰嘴裂的平均长度分别为(27.00±1.00)mm和(24.00±0.87)mm。在育雏过程中,雏鸟的羽色变化明显。     

种内及种间干扰对围栏内花鼠分散贮藏行为的影响

2009年9月在黑龙江省带岭区东方红林场10 m×10 m半天然围栏内模拟花鼠种内(不同性别)和种间(大林姬鼠)干扰竞争对花鼠分散埋藏红松种子行为的影响.实验分四个处理两个批次进行,依次为单只花鼠对照实验(雄性7只,雌性9只)、种内同性干扰竞争、种内异性干扰竞争和种间干扰竞争.结果表明:(1)花鼠雌性个体的分散埋藏强度...     

中国林蛙的分子系统关系

测定了 6种林蛙和用作外群的 2种侧褶蛙和 1种陆蛙的线粒体 12SrRNA基因序列 393bp。序列两两对位比较表明内外群间的位点替换率是 7 3%到 2 3 1% ,内群中物种间则为 0 0 %到 9 2 %。依据上述DNA序列 ,用距离法和最大简约法的系统发育分析表明 :①研究的 6种林蛙聚为一支 ,构成单系群 ,并有高的BPs值(90 %以上 )支持 ;② 6种林蛙可以分成 2个姐妹群 ,即中国林蛙、黑龙江林蛙和桓仁林蛙为一组 (BPs >94% ) ,峨眉林蛙、昭觉林蛙和镇海林蛙为一组 (BPs >5 0 % ) ;③昭觉林蛙与镇海林蛙有较近的亲缘关系 ;④中国林蛙的榆中种群与牡丹江种群间的遗传分化似乎达到了种级分化水平。     

模拟增温对青藏高原高寒草甸根系生物量的影响

在青藏高原高寒草甸布设模拟增温实验样地,采用土钻法于2012—2013年植被生长季获取5个土层的根系生物量,探讨增温处理下根系生物量在生长季不同月份、不同土壤深度的变化趋势及其与相应土层土壤水分、温度的关系。结果表明:(1)根系生物量在2012年随月份呈增加趋势,其中7—9月较大,其平均值在对照、增温处理下分别为3810.88 g/m~2和4468.08 g/m~2;在2013年随月份呈减小趋势,其中5—6月较大,其平均值在对照、增温处理下分别为4175.39 g/m~2和4141.6 g/m~2。增温处理下的总根系生物量高出对照处理293.97 g/m~2,而各月份总根系生物量在处理间的差值均未达到显著水平。表明在增温处理下根系生物量略有增加,但在生长季不同月份其增加的程度不同,致使年际间的增幅出现差异。(2)根系生物量主要分布在0—10 cm深度,所占百分比为50.61%。在增温处理下,0—10 cm深度的根系生物量减少,减幅为8.38%;10—50 cm深度的根系生物量增加,增幅为2.1%。相对于对照处理,增温处理下0—30 cm深度的根系生物量向深层增加,30—50 cm深度的根系生物量增加趋势略有减缓。可见,在增温处理下根系生物量的增幅趋向于土壤深层。(3)根系生物量与土壤水分呈极显著的递减关系,在增温处理下线性关系减弱;与土壤温度呈极显著的递增关系,在增温处理下线性关系增强。表明土壤水分、温度都可极显著影响根系生物量,但在增温处理下土壤温度对根系生物量的影响较土壤水分更为敏感而迅速。     

Entwicklungsgeschichte und Ultrastruktur von Pollenkitt und Exine bei nahe verwandten entomophilen und anemophilen Angiospermensippen derAlismataceae,Liliaceae, Juncaceae,Cyperaceae, Poaceae undAraceae

Some closely related members of the monocotyledonous familiesAlismataceae, Liliaceae, Juncaceae, Cyperaceae, Poaceae andAraceae with variable modes of pollination (insect- and wind-pollination) were studied in relation to the ultrastructure of pollenkitt and exine (amount, consistency and distribution of pollenkitt on the surface of pollen grains). The character syndromes of pollen cementing in entomophilous, anemophilous and intermediate (ambophilous or amphiphilous) monocotyledons are the same in principal as in dicotyledons. Comparing present with former results one can summarize: 1) The pollenkitt is always produced in the same manner by the anther tapetum in all angiosperm sub-classes. 2) The variable stickiness of entomophilous and anemophilous pollen always depends on the particular distribution and consistency of the pollenkitt, but not its amount on the pollen surface. 3) The mostly dry and powdery pollen of anemophilous plants always contains a variable amount of inactive pollenkitt in its exine cavities. 4) A step-by step change of the pollen cementing syndrome can be observed from entomophily towards anemophily. 5) From the omnipresence of pollenkitt in all wind-pollinated angiosperms studied one can conclude that the ancestors of anemophilous angiosperms probably have been zoophilous (i.e. entomophilous) throughout.

     

Identification and Characterization of the First Equine Parainfluenza Virus 5

正Dear Editor,Parainfluenza virus 5 (PIV5), known as canine parainfluenza virus in the veterinary field, is a negative-sense,nonsegmented, single-stranded RNA virus belonging to the Paramyxoviridae family (Chen 2018). The virus was first reported in primary monkey kidney cells in 1954 (Hsiung1972), then it has been frequently discovered in various     

Pathogenic Characterization and Full Length Genome Sequence of a Reassortant Infectious Bursal Disease Virus Newly Isolated in Pakistan

<正>Dear Editor,Infectious bursal disease (IBD) is one of the most important diseases of the poultry. The IBD virus (IBDV), a nonenveloped virus belonging to the Birnaviridae family with a genome consisting of two segments of double-stranded RNA (segments A and B), targets B lymphocytes of bursa of Fabricious leading to immunosuppression. In Pakistan,poultry farming is the second biggest industry and IBD is the second biggest disease threating the poultry sector.However, there is limited genome information of IBDV     

Mink Circovirus Can Infect Minks,Foxes and Raccoon Dogs

正Dear Editor,Mink circovirus (MiCV), which is clustered in the genus Circovirus of the family Circoviridae, was first described in minks from farms in Dalian, China in 2013 (Lian et al.2014). The complete single-stranded circular genome of the virus is 1,753 nucleotides long and contains two major open reading frames (ORFs), designated ORF1 (Rep gene)and ORF2 (Cap gene)(Lian et al. 2014; Ge et al. 2018).Sequence analysis has shown that MiCV is most closely     

CypA Regulates AIP4-Mediated M1 Ubiquitination of Influenza A Virus

Cyclophilin A (CypA) is a peptidyl-prolyl cis/trans isomerase that interacts with the matrix protein (M1) of influenza A virus (IAV) and restricts virus replication by regulating the ubiquitin–proteasome-mediated degradation of M1. However,the mechanism by which CypA regulates M1 ubiquitination remains unknown. In this study, we reported that E3 ubiquitin ligase AIP4 promoted K48-linked ubiquitination of M1 at K102 and K104, and accelerated ubiquitin–proteasome-mediated degradation of M1. The recombinant IAV with mutant M1 (K102 R/K104 R) could not be rescued, suggesting that the ubiquitination of M1 at K102/K104 was essential for IAV replication. Furthermore, CypA inhibited AIP4-mediated M1 ubiquitination by impairing the interaction between AIP4 and M1. More importantly, both the mutations of M1 (K102 R/K104 R) and CypA inhibited the nuclear export of M1, indicating that CypA regulates the cellular localization of M1 via inhibition of AIP4-mediated M1 ubiquitination at K102 and K104, which results in the reduced replication of IAV.Collectively, our findings reveal a novel ubiquitination-based mechanism by which CypA regulates the replication of IAV.