峨眉鱊的生物学资料及个体发育的观察

2004年9月~2005年10月对峨眉(Acheilognathus omeiensis)的生物学特性及个体发育进行了初步研究。峨眉为杂食性,栖息于水流较缓的水体中,其适宜的生活温度为4~28℃。1龄即性成熟;婚姻色和第二性征8月下旬开始出现,10月下旬更为明显,此时雌雄性腺均处于Ⅲ期;产卵期为翌年2月上旬至5月上旬,此时输卵管的长度为6.68~22.54 mm(12.539±4.810mm,n=50)。分批产卵,成熟卵量为26~219粒,平均为115粒;非成熟卵量为121~709粒,平均为243粒。产卵时对蚌有明显的选择性,仅将卵产于杜氏珠蚌(Unio douglasiae)的鳃瓣中。峨眉的个体发育分为蚌中发育和出蚌后发育两个时期,依其发育的形态特点,进一步将其生活史粗略地分为胚胎期、仔鱼期、稚鱼期、幼鱼期和成鱼期5个时期,分别记述了各期外部形态和内部器官的变化。     

连翘的二型花柱

报道了连翘中的二型花柱(长花柱和短花柱)。长花柱的柱头和雄蕊高度分别为6.12±0.05 mm和2.35±0.04mm,短花柱则为2.23±0.04mm和6.02±0.06mm。短花柱花的花冠大小明显超过长花柱。开放授粉条件下,长短花柱花的座果率分别为9.11 %±0.04%和8.93 %±0.07%。人工异交的座果率在长-短(36.8%±0.04%)与短-长(36.2%±0.07%)组合间无明显差异(F(1,39)=1 .38,P=0.14)。人工异交实验表明,传粉者限制可能发生在生长于中国东北部的人工连翘种群中,这可能是因为该地区早春的低温和多风气候条件影响传粉者的种类和活动。     

袁河花个体繁殖力研究

对采自江西省袁河的68尾花个体繁殖力及其与生物学指标的关系进行了研究。结果表明,体长在11.0～28.5cm、体重在27.3～418g的个体,绝对繁殖力(F)为540～47477.06粒,相对体长繁殖力(FL)和相对体重繁殖力(FW)分别为31.40～1683.96粒/cm、5.82～249.17粒/g,F、FL与年龄、体长、体重、体长×体重、净体重、卵巢重和成熟系数显著相关,FW与卵巢重和成熟系数显著相关;个体绝对生殖力与各指标逐步回归方程为:F=20062.53+604.307Wg+244.982W-1365.731L-134.223W0-4183.265K(R2=0.935,n=68),经卵径分布频数图初步推断,袁河花为一次产卵鱼。     

厚颌鲂(Megalobrama pellegrini)的繁殖生物学特征

从长江上游一级支流龙溪河收集了1382尾厚颌鲂开展繁殖生物学研究。结果表明,厚颌鲂繁殖期为4～7月份,盛期为4～5月份,在繁殖季节可借第二性征辨别性别。繁殖群体主要由2、3龄个体组成,总性比♀∶♂＝1∶1.83。厚颌鲂2龄初次性成熟（♀∶75%;♂∶94.7%）,3龄个体全部成熟。最小性成熟雌性全长189.0mm,体长158.0mm,体重72.1g,成熟系数2.7%;雄性全长179.0mm,体长149.0mm,体重57.1g,成熟系数2.2%。厚颌鲂绝对怀卵量为(59587.22±59018)粒,相对怀卵量为(212.64±89.50)粒/g或(230.96±137.63)粒/mm,绝对怀卵量和相对怀卵量均在5龄大幅增长。比较繁殖力以3龄组最高,2、4、5龄组相近。集群繁殖需要18℃以上水温和其他一些生态因子刺激,亲鱼追逐约1h左右产卵。     

切尾拟鲿的个体生殖力

于2013年4～5月在长江上游岷江河口区域采集63尾性腺发育至Ⅳ期的切尾拟鲿(Pseudobagrus truncatus)雌性个体,所有样本均测量其体长(L)、体重(M)、净体重(W)和性腺重(Wa)等生物学指标。取耳石鉴定年龄,测量卵径,用重量法计数个体绝对生殖力(F),并对体长相对生殖力(FL)、体重相对生殖力(FW)进行计算,用5种数学模型及多元逐步回归方程拟合个体生殖力与生物学指标的关系。结果显示,调查样本由2+～5+龄组成,个体绝对生殖力(F)为566～6758粒,平均为3056粒;体长相对生殖力(FL)68～469粒/cm,平均为234粒/cm;体重相对生殖力(FW)为45～349粒/g,平均为145粒/g。个体绝对生殖力(F)和体长相对生殖力(FL)与体长(L)、体重(M)和成熟系数(GSI)均呈幂函数相关;而体重相对生殖力(FW)仅与成熟系数(GSI)呈幂函数相关,和其他形态指标的相关性不显著。多元逐步回归分析结果表明,长江上游切尾拟鲿个体绝对生殖力(F)与体重(M)和成熟系数(GSI)密切相关,相关式为:F=16370.714+3284.028 GSI+58.361M(n=63,R2=0.973,P0.01);体长相对生殖力(FL)与体重(M)、净体重(W)和成熟系数(GSI)密切相关,相关式为:FL=251.749+18.961 M+684.273 W+3 268.421 GSI(n=63,R2=0.852,P0.01);而体重相对生殖力(FW)仅与成熟系数(GSI)相关:FW=138.590+837.641 GSI(n=63,R2=0.539,P0.01)。依据卵径频数分布结果推测,切尾拟鲿属于一次性产卵鱼类。     

陕西佛坪黑喉歌鸲的巢址特征和繁殖生态

2013年4～7月,采用样方法和直接观察法,在陕西佛坪分别对黑喉歌鸲的巢址特征和繁殖生态进行了初步研究。结果发现：黑喉歌鸲更倾向选择向阳、林冠稀疏、距水源较近的针阔混交林或针叶林下,秦岭箭竹丛林缘陡坡上的天然土洞内筑巢;巢口向上呈杯状,由竹叶、枯草、苔藓等编制而成,内无铺垫物。巢外底部垫有枯叶、干草等。巢外径长(100.37±4.00)mm,巢外径宽,(97.08±5.22)mm,巢高(48.18±2.24)mm。巢内径长(68.62±1.69)mm,巢内径宽(64.81±0.74)mm,巢深(36.07±0.30)mm。窝卵数(5±0.00)枚,卵重(1.91±0.05)g,卵长径(18.37±0.08)mm,卵短径(13.95±0.15)mm。孵化期12 d～13 d,孵化率为60%(n= 10),巢雏成活率为50%(n= 6),育雏期11 d。雏鸟的体重、体长的生长符合Logistic曲线方程拟合。天敌的捕食是影响黑喉歌鸲繁殖成功率的主要因素。关键词：黑喉歌鸲;繁殖生态;巢址特征;陕西佛坪     

利用甘蔗饲养红棕象甲的技术

介绍一种以甘蔗为饲料饲养红棕象甲Rhynchophorus ferrugineus Fab.的方法。将新鲜甘蔗切成段,置于培养皿中,放入恒温培养箱内,设置温度:(26±1)℃,RH:80%±10%,光周期:L∶D=0∶24。利用该方法饲养的红棕象甲世代历期130.80d,老熟幼虫平均体重5.51g,成虫单雌产卵量144.42粒,世代存活率21.67%。甘蔗饲养红棕象甲成本低,生物学特性恒定,可作为替代寄主扩繁虫源。     

广东北江马口鱼个体生殖力研究

于2009年3、4月,从北江中随机采集成熟度为Ⅳ期的马口鱼雌性个体55尾,测量体长(L)、体重(W)、净体重(Wn)和性腺重(Wo)等形态学指标,并用鳞片鉴定年龄,用重量法计数绝对生殖力(F),计算出体长相对生殖力(FL)、体重相对生殖力(FW)、成熟系数(GSI)和丰满度(K),并用5种数学模型及多元逐步回归方程拟合了马口鱼绝对生殖力与生物学指标的关系.结果表明,用于统计生殖力的马口鱼样本由1+～3+龄3个龄组组成;绝对生殖力在1486.29～12 025.78粒之间,平均为4842.42粒;体长相对生殖力在163.33～856.27粒/cm之间,平均为437.30粒/cm;体重相对生殖力在99.77～470.27粒/g之间,平均为207.29粒/g.绝对生殖力与体长、体重、净体重、性腺重、年龄呈抛物线相关,与成熟系数呈幂函数相关,与丰满度的关系不显著.多元逐步回归分析表明,绝对生殖力与体重和成熟系数密切相关,相关式为:F=-312.129+137.765W+108.715GSI(R2=0.719,n=55,F=57.089, P<0.001).     

杭州湾北部安氏白虾的繁殖生物学特征

采用2017年4月至2018年3月张网逐月采样数据分析杭州湾北部安氏白虾（Palaemon annandalei）的繁殖生物学特征。结果显示,安氏白虾体平均体长（32.0 ± 5.4）mm（14 ~ 51 mm,n = 3 210）,抱卵群体平均体长（36.3 ± 3.4）mm（27 ~ 51 mm,n = 375）。体重分布范围为0.016 ~ 1.700 g,n = 3 210,平均体重（0.565 ± 0.282）g,抱卵群体体重分布范围为0.400 ~ 1.700 g,n = 375,平均体重（0.868 ± 0.225）g。雌、雄个体间平均体长和平均体重都具有显著性差异（P < 0.01）;雌雄性比为1.27︰1,雌性个体数显著多于雄性个体数（P < 0.01）。繁殖期从4月下旬一直持续至10月下旬,6月和8月为两个繁殖旺期,抱卵率（B）和性比（S）具有显著线性相关关系（P < 0.05）,关系式为B = 41.80S﹣21.06（R2 = 73.9）。绝对繁殖力为17 ~ 179粒,平均绝对繁殖力（60 ± 26）粒,平均相对繁殖力（70 ± 24）粒/g,n = 375。绝对繁殖力（FA,单位粒）与体长（L,单位mm）、体重（W,单位g）均呈二次函数显著相关（P < 0.01）,关系式分别为FA = 0.29L2﹣18.52L + 342.67（R2 = 76.8）和FA = 97.32W2 ﹣100.75W + 71.66（R2 = 94.5）。卵长径分布范围为1.090 ~ 2.688 mm,平均长径（1.599 ± 0.158）mm,短径分布范围0.807 ~ 1.992 mm,平均短径（1.141 ± 0.118）mm,n = 2 787。研究表明,与20世纪80年代相比,安氏白虾个体朝小型化方向发展,繁殖周期延长,繁殖旺期由单峰型变为双峰型,这可能是生态环境持续恶化和高强度捕捞压力所致。     

钱塘江口弹涂鱼繁殖特征及早期发育

对采自钱塘江口沿岸滩涂(E 30°15',N 121°27')的弹涂鱼(Periophthalmus modestus)进行了繁殖特征和早期发育研究。弹涂鱼的个体绝对繁殖力(F)为1 432～2 978粒,平均1 998粒;体长相对繁殖力(FL)为36～62粒/mm,平均45粒/mm;体重相对繁殖力(FW)为528～1 530粒/g,平均864粒/g(n=83)。雌鱼性体指标(GSI)为8.47%～25.39%,平均14.49%(n=83);雄鱼GSI为0.10%～0.57%,平均0.25%(n=76)。弹涂鱼的成熟卵为沉性黏着性卵,有黏着丝,卵径(0.42±0.01)mm(n=500);受精卵椭球形,长径(0.75±0.02)mm,短径(0.56±0.03)mm,长短径比例0.74±0.03(n=300);受精卵为端黄卵,胚盘形成于动物极,作盘状卵裂。胚胎发育可划分为29个发育时相,在(27±0.5)℃、盐度10和pH 7.8±0.3条件下,经历124.13 h孵出仔鱼,所需的积温达3 351.34 h.℃。初孵仔鱼全长(2.17±0.09)mm(n=9),器官发育完善,胸鳍和鳔等器官已形成,眼睛有大量黑色素沉积,心率达(154.33±5.87)次/min(n=20)。实验条件下,初孵仔鱼投喂褶皱臂尾轮虫(Brachionus plicatilis)培育至23 d。3～4 d龄卵黄囊已完全吸收,进入后期仔鱼;7 d龄,脊椎骨开始弯曲,消化管呈折型;11 d龄,尾鳍开始分化,尾椎骨开始上翘,上颌出现牙齿;15 d龄,下颌出现牙齿;23 d龄,尾鳍鳍条发育完整,除第一背鳍外,其他各鳍已形成。幼鱼在培育过程中出现了两个死亡高峰期,第一个高峰出现在仔鱼孵化后5～7 d龄的开口期,第二个高峰则出现在20～23 d龄的变态期。     

Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis

It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.     

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.     

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     

Selection with two alleles and complete dominance

For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.