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原卵黄目(Prolecithophora)柱口科(Cylindrostomidae)肠口涡虫属(Enterostomula)为海栖涡虫,全球记录3种,在中国未见报道。作者在广东省深圳市深圳湾海边(22°31'N,113°56'E)采集到一种海栖涡虫。本文对该种涡虫进行了较为详细的比较研究,鉴定为柱口科肠口涡虫属格氏肠口涡虫(E.graffi de Beauchamp,1913),为中国新纪录科新纪录属一新纪录种。该种涡虫多数个体背部具2条黑色横纹,部分个体背部花纹有明显变化。眼点2对。雌雄同体,精巢、卵巢各1个。受精囊位于卵巢与子宫之间;子宫位于体末端,后接一微小的外阴道。本文发现:①该涡虫的尾部腹面具有一个交配囊及一根雌性生殖管,交配囊是一个由肌肉层组成的袋状囊,同时与子宫、雌性生殖管相连;②雌性生殖管外围有明显的生殖腺包裹;③雌性生殖管孔、阴茎孔与口孔一起通往体外;④此种涡虫喜分泌黏液将微小杂质粘结呈半球状窝,虫体隐藏于窝内。 相似文献
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大口涡虫属所有物种均为雌雄同体,具一套交配器官。作者于2015年在广东省的两处淡水环境,首次发现2个具有双雄性交配器官的大口涡虫(Macrostomum sp.)标本。通过对活体、整装片、连续组织切片的显微镜观测,发现2只标本的两套交配器官呈左右排列;每套交配器官具备完整的假储精囊、储精囊、颗粒囊与交配刺;假储精囊与储精囊内具有精子;雄孔分别为1个与2个;交配刺的结构与中国已经记录的物种都不相同。本研究对其做了较为详细的描述,并初步探讨了大口涡虫多交配器官发生的原因。 相似文献
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中国涡虫一新纪录科(扁形动物门,单肠目,盲扁虫科)背睾涡虫属一新种 总被引:1,自引:0,他引:1
记述了中国涡虫单肠目1新纪录科背睾涡虫属1新种,即中国背睾涡虫Phaenocor asinensis sp.nov.。新种的主要鉴别特征是:外轮廓呈长子弹形,后缘呈刀切状;精巢长度占体长的2/3,位于卵黄腺的背部。阴茎表面小刺呈犬牙状,其内折部中段具4个矩形的粗刺。子宫有2个开口,一端连接卵巢,另一端连接生殖腔。卵黄腺呈条形,具短分支,左右卵黄腺无衔接。生活于淡水。标本保存在深圳大学生命科学学院形态学研究室。 相似文献
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《四川动物》2016,(1)
本文记述淡水涡虫类单肠目Rhabdocoela达氏科Dalyelliidae小达氏涡虫属Microdalyellia一新种,广东小达氏涡虫Microdelyellia guangdongensis Wang et Rong,sp.nov.,模式标本由卢彦宏于2013年6月9日采自广东省深圳市石岩水库(22°40'58″N,113°53'42″E);杰氏涡虫属Gieysztoria一新种,七星岩杰氏涡虫Gieysztoria qixingyanensis Wang et Rong,sp.nov.,模式标本由刘旭坤于2014年8月6日采自广东省肇庆市七星岩风景区(23°04'32″N,112°28'46″E)。对2个涡虫新种的形态特征作了详细描述,并分别与小达氏涡虫属和杰氏涡虫属近似物种进行了比较。所有标本保存于中国科学院国家动物博物馆。 相似文献
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《四川动物》2017,(1)
本文对分布于广东省深圳市侨城湿地(113°58'E,22°31'N)咸淡水的一种单肠目Rhabdocoel涡虫进行了形态、发育及18S r DNA与28S r DNA分子系统学的分析与比较。结果表明,此涡虫为达氏科Dalyelliidae铲形杰氏涡虫Gieysztoria knipovici Beklemischev,1953,为中国新纪录种。该物种模式标本分布于欧洲黑海近岸。本研究详细描述了其外部形态与内部结构特征,首次发现该涡虫精巢超长,前端达咽部,后端至腹侧,呈长条形(该属涡虫2个精巢呈球形或椭圆形,位于肠后腹侧);除了骨质阴茎之外还具有可再生的骨质阴茎鞘。阴茎鞘位于骨质阴茎外侧,半包裹骨质阴茎,呈长条形骨质结构。交配后的个体常在交配囊内发现阴茎鞘1~5个。鉴于该物种特殊的形态学特征,其分类地位还有待进一步研究。 相似文献
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运用常规组织学方法和NADPH-d组织化学方法,研究了薄背涡虫 Notoplana humilis 生殖系统的组织结构和一氧化氮合酶的分布.其雄性生殖系统包括精巢、储精囊、阴茎、雄性生殖孔,精巢壁由一薄层薄膜组成,每个精巢内都含有不同发育时期的雄性生殖细胞,且精子发育无明显同步性;储精囊呈螺旋状排列在雄性生殖孔附近,囊壁由单层扁平上皮组成;阴茎为粗大的球形,外壁由柱状上皮细胞和数层肌细胞组成.雌性生殖系统包括输卵管、生殖腔、雌性生殖孔和受精囊,但不形成集中的卵巢和卵黄腺.雌雄生殖孔、生殖腔、受精囊、阴茎等部位呈NADPH-d强阳性反应. 相似文献
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本研究报道单肠目Rhabdocoela斯库台科Scutariellidae斯库台涡虫属Scutariella新种:中国斯库台涡虫,新种Scutariella sinensis sp.nov.,对其进行了形态学、分子系统学等研究。新种的主要鉴别特征:(1)二支卵黄腺在背部两侧沿肠管分布,在近肠后部愈合,整体呈"U"型;(2)生殖孔位于肠前端腹侧;(3)咽腺丰富,位于咽肠交界处的两侧;(4)精巢、卵巢位于肠道前1/3腹侧。新种的18S rDNA和28S rDNA分子系统发生研究首次提供了切头类斯库台科的分子数据,确定切头亚目Temnocephalida的分类地位及该亚目与吸虫类的进化关系。 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