遗鸥舌头微观结构研究

采用光学显微镜及电子扫描显微镜对遗鸥Larus relictus舌头微观结构进行研究。结果显示:遗鸥的舌头呈细长三角形,由舌尖、舌体、舌根3部分构成。舌尖分叉先端特化为角质的舌突起,舌尖表面有大量脱落的上皮细胞,细胞表面为指纹状;舌体表面光滑,上皮细胞为细长形,表面呈微嵴状;舌根表面有少量的唾液腺开口分布。从功能上分类,遗鸥舌头符合采集食物型舌头结构特征。舌乳突发育不完善,仅锥状乳突在舌体和舌根分界处及上颌表面呈列状分布,乳突末端指向口腔内部。舌黏膜内未见味蕾分布。遗鸥口腔结构的特点与部分鸥科Laridae鸟类区别明显,这可能与遗鸥栖息环境不断恶化、食物种类和数量匮乏有关。     

华鲮鳃表面形态结构扫描电镜观察

应用扫描电镜对华鲮Sinilabeor rendahli鳃耙、鳃弓、鳃丝和鳃小片的形态结构进行了观察.鳃耙和鳃弓表面凹凸不平,分布着大量丘突.鳃丝和鳃耙表面有大量粘液细胞分布,鳃丝上皮细胞表面密布微嵴,氯细胞附着在鳃丝表面和鳃小片侧表面.鳃小片薄、表面凹凸不平,垂直排列在鳃丝上.鳃丝和鳃小片的表面形态结构特征有助于提高鱼鳃的气体交换效率.     

溴乙酰胺对钉螺超微结构的影响

本文应用电子显微镜技术观察了正常钉螺及溴乙酰胺作用后的钉螺头足部软体组织及肝脏组织的超微结构。头足部软体组织有上皮层、上皮下层及肌层。上皮层有三种细胞:无纤毛上皮细胞、纤毛上皮细胞及含有大量粘性分泌颗粒的腺体细胞。上皮层细胞内含有丰富的线粒体、内质网及张力细丝。基底膜将上皮细胞与上皮下层分开,上皮下层有含色素颗粒的细胞。肌层为梭形细胞,核居中央,无横纹。溴乙酰胺作用24小时后,钉螺头足部的上皮细胞与肝脏腺管细胞肿胀,核增大;染色质凝集,线粒体肿胀、嵴断裂呈空泡状,粗面内质网变粗呈短管状,排列混乱,或呈同心圆指纹状排列。这些病变与生化代谢结合进行了讨论。     

松江鲈鱼皮肤的显微和亚显微结构观察

采用光学显微镜、扫描电镜和透射电镜,对松江鲈鱼（Trachidermus fasciatus）成体皮肤的显微结构和亚显微结构进行了观察。结果表明,松江鲈鱼体表不同部位皮肤的厚薄不一,但基本结构相似。皮肤由表皮和真皮层构成。松江鲈鱼的皮肤裸露无鳞,表皮层较薄,由约4～8层细胞构成,主要由复层上皮细胞和黏液细胞及基底细胞组成。表层细胞呈扁平、多边形, 细胞之间主要靠桥粒紧密连接,连接处形成增厚的边缘嵴状突起。表皮细胞游离面向内凹陷,表面形成指纹状微嵴。黏液细胞呈圆形或卵圆形,散布在上皮细胞之间。黏液细胞内的黏原颗粒具有椭圆颗粒状、均匀致密的块状和疏松丝状3种不同形态。真皮通过基膜与表皮相连,由稀疏层和致密层构成。真皮结缔组织在腹部较厚而在其他部位较薄。表皮与真皮连接处有色素层,头部、背部、尾柄和体侧皮肤色素细胞分布多,色素层明显,而腹部和颏部皮肤缺少色素。松江鲈鱼黄河群体真皮层中有角质棘状突起,而滦河群体则无。头部、体侧和尾柄处皮肤上还分布有侧线孔和表面神经丘等感觉器官。     

松江鲈鱼皮肤的显微和亚显微结构

采用光学显微镜、扫描电镜和透射电镜,对松江鲈鱼(Trachidermus fasciatus)成体皮肤的显微和亚显微结构进行了观察。结果表明,松江鲈鱼体表不同部位皮肤的厚薄不一,但基本结构相似。皮肤由表皮和真皮层构成。松江鲈鱼的皮肤裸露无鳞,表皮层较薄,由约4～8层细胞构成,主要由复层上皮细胞和黏液细胞及基底细胞组成。表层细胞呈扁平、多边形,细胞之间主要靠桥粒紧密连接,连接处形成增厚的边缘嵴状突起。表皮细胞游离面向内凹陷,表面形成指纹状微嵴。黏液细胞呈圆形或卵圆形,散布在上皮细胞之间。黏液细胞内的黏原颗粒具有椭圆颗粒状、均匀致密的块状和疏松丝状3种不同形态。真皮通过基膜与表皮相连,由稀疏层和致密层构成。真皮结缔组织在腹部较厚而在其他部位较薄。表皮与真皮连接处有色素层,头部、背部、尾柄和体侧皮肤色素细胞分布多,色素层明显,而腹部和颏部皮肤缺少色素。松江鲈鱼黄河群体真皮层中有角质棘状突起,而滦河群体则无。头部、体侧和尾柄处皮肤上还分布有侧线孔和表面神经丘等感觉器官。     

人工养殖稀有鮈鲫消化道组织学观察

采用活体解剖和显微技术对人工养殖的稀有鮈鲫消化道组织结构进行了详细观察,并描述了其形态结构。结果表明:稀有鮈鲫为杂食性无胃鱼,肠道系数0.64±0.06。消化道包括口咽腔、食道、肠和肛门。口咽腔和食道粘膜层为复层扁平上皮,内含较多杯状细胞、粘液细胞和少量味蕾;食道粗短,肌肉层发达。肠由前肠、中肠和后肠三部分组成。肠道由前到后,粘液细胞数量逐渐增多,粘膜皱褶数量逐渐减少,粘膜皱褶高度逐渐降低。     

花生成熟花粉的超微结构

花生（Arachis hypogaea L．）成熟花粉为二细胞型,具3个萌发沟,少数有4个。外壁呈蜂窝状。花粉壁由覆盖层、基粒棒、外壁内层及内壁构成。线粒体嵴密集、相互平行,脂体被粗面内质网包围。粗面内质网与外核膜相连,亦与线粒体相连。高尔基体甚少。营养核无核仁及染色质,与生殖细胞相连形成雄性生殖单位（male germ unit）。生殖细胞锤形、有壁,见一末端延伸成长尾状（长8μm）。细胞质含核糖体、线粒体、微管,未见体。在有些生殖细胞核内观察到具双层膜、少量嵴及深色内含物的球形结构,其米来源及本质尚不知,有待进一步研究确定。     

珠江口池养梭鱼鳃的光镜、扫描和透射电镜观察

应用光学显微镜、扫描电镜和透射电镜对珠江口池塘养殖梭鱼Liza haematocheila鳃的组织结构、表面形态特征及鳃小片超微结构进行了观察。结果表明梭鱼具有4对鳃,每个鳃由鳃弓、鳃丝、鳃小片和鳃耙组成。梭鱼鳃丝和鳃小片的表面结构和超微结构与其他硬骨鱼类的基本相似,鳃丝表面分布有众多规则或不规则的环形微嵴、沟、坑、孔等结构。鳃丝分为呼吸区和非呼吸区,呼吸区较为平滑,上皮细胞表面无微嵴,呈皱褶状;非呼吸区分布有沟、坑、孔等结构,上皮细胞有较规则的指纹状微嵴。鳃小片是最主要的呼吸场所,由基膜、上皮细胞、内皮细胞、柱细胞和毛细血管网组成。泌氯细胞主要分布在鳃小片基部,并有开口通往外界。本文还探讨了梭鱼鳃的结构与其功能的密切关系。     

瓦氏黄颡鱼的胚后发育观察

2002年5~6月,在四川省泸州市、合江县分数批收集到长江野生瓦氏黄颡鱼(Pelteobagrusvachelli)亲本,通过人工催产、人工授精获得受精卵,对其胚后发育过程进行了观察。瓦氏黄颡鱼的胚后发育过程可以分为卵黄囊仔鱼、晚期仔鱼和幼鱼3个阶段。初孵仔鱼淡黄色,肌节40对,平均全长5.2mm。水温20~22℃时,孵出后第3d口张开;第7d开始摄食;第9d卵黄吸尽,此时鱼苗平均全长12mm,卵黄囊仔鱼阶段结束。晚期仔鱼阶段的仔鱼,胸鳍、尾鳍、臀鳍、背鳍、腹鳍先后发育,至鳍褶消失时晚期仔鱼阶段结束。经过30d的生长和发育,进入幼鱼阶段;此时平均全长达37mm,其形态特征和生态习性均与成鱼相似。     

蟹累枝虫的光镜及电镜观察

利用活体观察、蛋白银染色及电镜技术对蟹累枝虫(Epistylis eriocheiri)的形态学、表膜下纤维及超微结构进行了较为系统的描述,研究发现:(1)光镜下该种群体双叉分支,活体时虫体表膜柔软,完全伸展时呈长筒状;大核马蹄形,呈横位;伸缩泡单个,斜卧口围缘下方。口围缘纤维上连细密的环状纤维,下接两端较为粗壮,中间细长的纵长纤维,构成了连续的表膜下纤维系。(2)电镜下该种表面具沟、嵴、横纹结构,沟嵴相互交错;口围纤毛花瓣状;虫体表膜层呈齿状,具嵴状突起、泡间微管、表膜孔,胞质层包括内含胞器单一的致密原生质层和富含胞器的疏松原生质层。研究对该种的上述特征在虫体的收缩机制及与其他相似种之间的关系等方面进行了讨论。       

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.