首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 640 毫秒
1.
本文通过对丽突鼻蝗RhinotmethispulchrisXietZheng、景泰突颜蝗EotmethisjintaiensisXietZheng、友谊华癞蝗SinotmethisamicusB.-Bienkot和短翅华癞蝗SinotmethisbrachypterusZhengetXi精子的比较研究,发现它们的精子的线粒体衍生体超微形态结构及精子发生过程中第7、8两期精细胞线粒体衍生体周围微管排数十分相似,而在精子的外形长度、中心粒侧体超微形态结构及线粒体衍生体的大小等项特征方面存在着一定差异,这些差异只是在种间精子的鉴别方面有一定的意义,而不具有属级水平的鉴别意义。  相似文献   

2.
蝗总科染色体研究及科级综合比较(直翅目)   总被引:13,自引:0,他引:13  
对国际范围内蝗总科染色体研究简史及细胞分类学研究概况进行了回顾,并对我国蝗总科细胞分类学研究进展作了简要介绍。在此基础上,本文根据染色体数目、形态、染色体分组型式、性染色体位置、C带结构特征及异染色质总含量值等多方面特征对蝗总科8个科细胞分类学相互关系进行了综合比较。结果表明:癞蝗科染色体特点明显,进化位置独特;锥头蝗科与瘤锥蝗科相互近缘;斑腿蝗科与斑翅蝗科较为相近,网翅蝗科与槌角蝗科在染色体多项  相似文献   

3.
蝗总科部分种类Cyt b基因序列及系统进化研究   总被引:41,自引:5,他引:36  
蝗总科8个科10个种的线粒体DNA细胞色素b(Cyt b)基因部分序列被测定分析,比较同源性,计算核苷酸使用频率并构建NJ分子系统树。在获得的432bp的序列中,A T约占70.4%,其中177个核苷酸位点存在变异(约占41.0%),DNA一级序列数据显示,该8科蝗虫间DNA序列变异丰富。用日本蚱作外群构建的NJ树表明:瘤锥蝗科较为原始,而癞蝗科与槌角蝗科关系较近,为比较进化的类群,蝗总科8科的起源关系为:瘤锥蝗科→班翅蝗科和锥头蝗科→斑腿蝗科→剑角蝗科→网翅蝗科→槌角蝗科和癞蝗科,上述研究结果与传统形态分类学结论不完全一致,并就此进行了讨论。  相似文献   

4.
本文通过对日本黄脊蝗Patangajapoinca(I.Bd),短角直斑腿蝗StenocatantopsmistshenkoiWill和霍山蹦蝗SinopodismahoushanaHuang精子的比较,发现了它们的精子的线粒体衍生体和中心粒侧体的超微形态结构十分相似,在精子发生过程中7、8两期精细胞线粒体衍生体周围微管的排数相一致,这3个种精子间的差异主要反映在外形头和尾的长度,线粒体衍生体的大  相似文献   

5.
为蝗虫预测与综合防治提供参考,应用五点取样法、昆虫分类学和相关动物地理学方法对通辽各地蝗虫物种多样性及其分布进行研究。通辽共分布蝗总科7科12亚科37种,以斑翅蝗科Oedipodidae物种最多(14种),其次为网翅蝗科Arcypteridae(10种)。多样性分析表明扎鲁特旗具有最高的Shannon-Wiener多样性指数和丰富度指数,但均匀度最低;开鲁县具有最低的Shannon-Wiener多样性指数和丰富度指数。从科的分布范围看,剑角蝗科Acrididae、斑腿蝗科Catantopidae和斑翅蝗科在通辽各地均有分布;而癞蝗科Pamphagidae仅在扎鲁特旗有分布。从物种分布看,黄胫小车蝗Oedaleus infernalis Saussure和短星翅蝗Calliptamus abbreviatus Ikonnikov分布最广,其次为亚洲小车蝗Oedaleus decorus asiaticus B.-Bienko。从分布地区看,扎鲁特旗为物种最丰富(34种)。研究结果显示通辽市蝗虫物种多样性及分布特点与各地的草地面积和类型密切相关。  相似文献   

6.
本文通过对癞短鼻蝗Filchnerella pamphagides karny、青海短鼻蝗F.kukunoris B.-Bienko和肃南短鼻蝗F.sunanensis Liu精子的比较,发现它们的精子在外形头和尾的长度、线粒体衍生体的大小及中心粒侧体超微形态结构方面存在着一定的差异,而精子发生过程中七、八两期精细胞线粒体周围微管的排数和精子的线粒体衍生体超微形态结构十分相似。  相似文献   

7.
蝗总科昆虫雌性下生殖板及系统发育关系研究(直翅目)   总被引:13,自引:0,他引:13  
在对蝗总科103种蝗虫雌性下生殖板进行形态学研究的基础上,对蝗总科8个科以及斑腿蝗科的稻蝗属,伪稻蝗属,拟凹背蝗属,卵翅蝗属和剑角蝗科的卡蝗属,选择导卵器正面观形态等15个性状,以蚱总科为外群确定性状的极性和状态,用Henning86V1.5软件对它们的系统发育关系进行地序分类研究。结果支持刘举鹏在1991年依蝗卵结构所提出的蝗总科分类系统,同时结果也表明蝗属,伪稻蝗属,拟凹背蝗属,卵翅蝗属和卡蝗  相似文献   

8.
基于核内核糖体小亚基序列的蝗总科系统发育关系分析   总被引:6,自引:3,他引:6  
用核糖体SSURdna全序列对蝗总科(Acridoidea)进行了分子系统学研究。依据测定的8种蝗虫的SSU Rdna全序列 (平均 1.844 bp),并从GenBank中选取了6种内群种类和2种外群种类的SSU Rdna同源序列,进行序列分析。利用Clustal、MEGA 和 PHYLIP 软件构建分子系统树(距离邻接法Neighbor-Joining,NJ;最小进化法 Minimum Evolution)。结果显示: (1) 蝗总科是一个单系类群;(2) 锥头蝗科(Chrotogonidae)和瘤锥蝗科(Pyrgomorphidea)亲缘关系较近,为蝗总科最原始的类群;(3) 网翅蝗科(Arcypteridae)和槌角蝗科(Gomphoceridae)有较近的亲缘关系; (4) 斑翅蝗科 (Oedipodidae)为最进化的类群; (5) SSU Rdna序列保守性强,转换transition)取代的速率大于或接近颠换(transversion)取代的速率;(6) 在系统树中,总科首先分离,大多数同科不同属的类群以高置信度聚合在一起,说明SSU Rdna序列适合用于蝗总科的系统发育关系分析。  相似文献   

9.
陕西汉中地区蝗虫种类及区系特点   总被引:3,自引:0,他引:3  
张宏杰  霍科科 《昆虫知识》2005,42(5):562-565
汉中地区的蝗总科昆虫有5科33属51种,锥头蝗科Pyrgomorphidae1属2种,斑腿蝗科Catantopidae9属19种,网翅蝗科Arcypteridae5属12种,斑翅蝗科Oedipodidae12属13种,剑角蝗科Acrididae5属5种。汉中地区蝗总科的昆虫以东洋界为主,共23种,占45.1%,其次为汉中地区特有种类10种,占19.6%,古北界和两界共有种类均为9种,均占17.6%。物种数量在各县区分布不均匀。  相似文献   

10.
蝗总科部分种类16S rDNA的分子系统发育关系   总被引:20,自引:0,他引:20  
将自测的我国直翅目蝗总科8科8个种和从互联网GenBank中检索到相关物种的线粒体基因组:16S rDNA序列片段进行同源性比较,计算核苷酸使用频率,并构建分子系统树。在获得的480bp的序列中。A T约占70.7%,G C为29.3%,颠换取代(transversion)的速率大于或接近转换取代(transition)的速率,其中188个核苷酸位点存在变异。研究结果表明:在直翅目蝗总科有差异的188bp中,属内种间的碱基序列差异仅为1.5%,科内属间为3.5%~3.6%,科间差异为4.8%~15.8%,亚目间差异达到15.2%~25.6%。分子系统树表明:科内的属和属内的种均优先聚在一起;蝗总科8科的起源关系为:锥头蝗科→瘤锥蝗科→癞蝗科→斑翅蝗科→剑角蝗科→网翅蝗科和槌角蝗科→斑腿蝗科;锥头蝗科与瘤锥蝗科关系较近,是蝗总科内最原始的类群;槌角蝗科和网翅蝗科互为姐妹群,与最进化的斑腿蝗科关系较近;蚤蝼科为独立的一支,最先分出,似为一个亚目,与现用的分类系统有明显差别;哈螽科(螽嘶总科)和蟋蟀科聚在一起为剑瓣亚目(Ensifera),蚱科和蝗总科的8科组成短瓣亚目(Caehfera),同现用的分类系统。  相似文献   

11.
12.
13.
14.
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   

15.
16.
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   

17.
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   

18.
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   

19.
20.
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   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号