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作者对钩刺亚册虫的纤毛器的形态结构做了光镜和电镜水平的研究,结果表明:口侧动基索均为单动基列结构,其中PK1仅后行至胞口后方;背触毛含约10对紧密排列的毛基体,后端不与其它体动基列相联;射出体除沿胞口分布外,在虫体顶端丛集成盾;虫体前部自右向左扭转约180^o。 相似文献
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钩刺斜管虫无性生殖期间的口纤毛器及细胞发生研究(原生动物:纤毛虫) 总被引:1,自引:0,他引:1
钩刺斜管虫口和体纤毛器演化模式是研究该类动物个体发生的优秀模型。通过跟踪研究,澄清了后仔虫口器发生以及体纤毛器起源上的几点疑问,并证实:体左侧二列片段动基列为同源再造而非来自老结构的分裂或复制;三列围口纤毛均为双动基列构造;后仔虫口原基场的构建系由5列体动基列共同参与完成的,其中最左侧两列短的原基片段与原基1整合为一体,从而发展成营养期虫体的外围口动基列;后仔虫背触毛原基为独立发生。 相似文献
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对采自湖北省洪湖地区的泽蛙(Fejervarya limnocharis)肠道内寄生的泽蛙原蛙片虫进行了形态学再描述, 包括活体形态、固定染色标本形态及扫描电镜下超微结构。样本形态特征参数值与Nie(倪达书)首次发现并命名时所记述标本参数值颇为相符(包括体长、体宽, 核长、核宽)。此外, 本文对2个重要的分类特征进行了补充和修正: (1)缝线位于虫体顶端, 贯穿背腹侧; 所有体动基列均从缝线两侧发出。(2)胞核分裂时在两新核间产生的连接细丝, 在虫体整个生活周期一直存在。并针对这2点特征与其他已知的原蛙片虫属种类进行了比较和讨论: 认为缝线结构是较为稳定的分类特征之一, 体动基列均由此处生发并与虫体纵轴平行延伸; 推测泽蛙原蛙片虫子代虫体中的2个胞核均来自于母体中同一个核, 而其2核间的连接细丝可能是胞核分裂进化历程中比较原始的残迹。 相似文献
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利用蛋白银染色技术对采自青岛沿海砂隙的寡毛类纤毛虫Strombidium kielum进行了形态学重描述,发现该种在寡毛类纤毛虫中具有独一无二的纤毛下器模式,因此为其建立了1新属Varistrombidium,特征为具有5条斜穿虫体的体动基列,其中体动基列1和2延伸到虫体背部,终止于虫体尾端。对Varistrombidium kielum(Maeda&Carey,1985)nov.comb.的小亚基RNA序列分析表明,该种位于Strombidiidae科内,与其形态学相近种Omegastrombidium elegans聚在一起。同时对其小亚基RNA序列可变区2的二级结构进行了预测并与其形态学相似种进行了比较。还对Apostrombidium pseudokielum Xuet al.,2009进行了补充性描述。 相似文献
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尖前口虫的口器发生研究(纤毛门, 膜口目) 总被引:1,自引:0,他引:1
研究了咽膜类纤毛虫尖前口虫无性生殖期的核器及口器的演化.其发生特征为;1)新的口原基形成于原前庭动基列与口侧膜间,表观为原口侧膜分裂而致;2)随着形态发生的进行,由口原基依次演化出后仔虫的三片咽膜、口侧膜和三条前庭动基列;3)原口器完全被前仔虫所继承;4)体纤毛器在整个形态发生过程中一直保持双动基列结构.
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对采自山东、广东和香港沿海的八种盾纤类纤毛虫: 冠帆口虫、维亚可夫帆口虫、蠕形康纤虫、贪食迈阿密虫、异海洋尾丝虫、中华后阿脑虫和两种蟹栖异阿脑虫相似种进行了形态学研究。其中, 中国南海新记录种维亚可夫帆口虫种群与Wang, et al.所描述种群以及中华后阿脑虫新种群与Song Wilbert记述的青岛种群和南极种群相比, 在个体大小和体动基列数目上均有所差异; 贪食迈阿密虫潍坊种群的体动基列恒为12列, 与Song Wilbert的报道有较大差异。两种异阿脑虫与蟹栖异阿脑虫在口纤毛器结构和体形上完全相似, 但在体动基列数目上有明显差异, 因数据不足, 暂定为蟹栖异阿脑虫相似种。
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(四)纤毛虫的细胞小器和胞器复合 1.纤毛、动胞器(kinetid)和动胞器列(kinety)纤毛的超微结构与鞭毛的基本相同,其基部的一段名动体,是由9组三联体微管围成的短圆柱状体。动体可成双存在,也可成单或多个聚集存在。动体和与它相联的纤维加上围绕这一动体单元的表膜结构合称为动胞器。许多动胞器前后相联成行,叫做动胞器列。与动体相联的各种纤维及微管可能具有传导或支持作用。另有可发射刺丝的刺丝泡。高等纤毛虫有的纤毛发生合并形成棘毛,有的棘毛含数十根纤毛,形如毛笔。棘毛又称复动胞器(polykinetid)。 2.口旁膜(paroral membrane)和小膜(membranelle)属于口纤毛器的一部分。口 相似文献
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本文对人工感染获得的纤细背孔吸虫Notocotylus attenuatus(Rud.,1809)成虫的体被进行了扫描电镜观察。发现虫体不同部位的体被有着不同的被式。口吸盘处为放射状条索;虫体腹面口吸盘后至中列第一腹腺前为无棘区,呈石板条块状,其余部分均为银杏叶和尖叶形体棘所覆盖。虫体背面边缘一圈为有棘区,其圈内为珠状突起结构。 相似文献
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作者从卵圆鲳鲹Trachinotus blochii分离了一株刺激隐核虫Cryptocaryon irritans,再经人工感染的方法收集各期虫体,制成电镜样品,对虫体的胞口超微结构进行了观察.同时,用银染和免疫荧光染色以及共聚焦显微镜对虫体的胞口周围及内部的纤维和微管进行了观察.结果表明刺激隐核虫的胞口结构与前口类纤毛虫(Prostome)的胞口结构有诸多相似之处,而与归属于膜口类Ophryoglenina小瓜虫差异较大,因此,作者认为刺激隐核虫的分类更适合归属于前口类Prostome,而不是膜口类Ophryoglenina. 相似文献
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借助活体观察和银染法对6种淡水纤毛虫(纵长板壳虫Coleps elongatus、瓜形原膜袋虫Protocyclidiumcitrullus、亨氏累枝虫Epistylis hentscheli、钟形钟虫Vorticella campanula、长柄球吸管虫Metacineta macrocaulis、四分锤吸管虫Tokophrya quadripatita)的形态和纤毛图式进行了详尽研究。本工作首次描述了亨氏累枝虫、四分锤吸管虫、纵长板壳虫的中国种群,同时揭示了亨氏累枝虫长期未知的纤毛图式特征并给出该种类的新定义: 虫体高钟形,活体大小约(100-130) m(60-65) m; 伸缩泡1个,腹位; 大小核各1枚,大核C型; 群体为规则对称二叉分枝; 口区三片小膜均由三列动基列组成,第三小膜由三列等长的动基列组成,其终止处高于第一小膜下端; 虫体前端到反口纤毛环间的银线约71-74条,反口纤毛环到帚胚间的银线约35-47条; 淡水生境。此外,本研究对长柄球吸管虫、钟形钟虫、瓜形原膜袋虫进行了重新描述,补充了显微照片。 相似文献
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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. 相似文献
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RICHARD E. NORRIS 《Botanical journal of the Linnean Society. Linnean Society of London》1991,106(1):1-40
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. 相似文献
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JOAN VALUÈS MONTSERRAT TORRELL NÚRIA GARCIA JACAS 《Botanical journal of the Linnean Society. Linnean Society of London》2001,137(4):399-407
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. 相似文献
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肝癌中HBV和HCV基因和抗原的分布及意义 总被引:1,自引:0,他引:1
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 相似文献
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H.-R. GREGORIUS 《Biological journal of the Linnean Society. Linnean Society of London》1984,23(2-3):157-165
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. 相似文献
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. 相似文献