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1.
蝗虫染色体分带技术的研究   总被引:2,自引:0,他引:2  
马恩波  姚爱玉 《遗传》1999,21(3):28-30
本文对采自长沙岳麓山的中华稻蝗〔Oxya chinensis (Thunberg)〕和采自杭州的小稻蝗〔Oxya hyla intricata (Stal) 〕进行了染色体C带、R带、N带和A带的处理研究。结果表明,C带显示结构异染色质,其位置在不同分裂相中较为稳定;R带即G带的反带,带纹较C带丰富,在粗线期最为明显,本文观察到不同的温育条件可影响R带产生的效果;N带和Ag带可相互参照比较,从而为NOR的准确定位提供依据;A带即荧光带,本文对其显带程序作了一定的改进。 Abstract:In this paperOxya chinensis (Thunberg) collected from the Yuelu Mountains in Changsha, Hunan Province andOxya hyla intricata (Stal) collected from Hangzhou, Zhejiang province were analysed by chromosomal C-banding、R-banding、N-banding、Ag-banding and A-banding. The results showed that the constitutive heterochromatin was stained in C-banding, and it relatively stable; R-banding was the reverse of G-banding, its bands were relatively obvious at the pachytene and abundent, it may be because of the selective extracts that cause the bands evident, the different effects were surveyed under the various incubation conditions; Both N-banding and Ag-banding can stain the nucleolar organizer and the two were compared in this paper; The A-banding was a little improved in the light of the banding process.  相似文献   

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We evaluate comparative toxicity of malathion in the two populations of the grasshopper Oxya chinensis, collected from Daixian and Fanshi of Shanxi province, China. General esterases and acetylcholinesterase (ACHE) from the two populations were characterized and compared. LD50 of the Daixian population (7.58 μg/g body weight) was 2.02-fold higher than that of the Fanshi population (3.75μg/g body weight). General esterase-specific activities in the Daixian population were 1.91,130 and 1.85-fold higher than those in the Fanshi population, when α-NA, α-NB and β-NA were used as a substrate, respectively. Kinetic studies of general esterase showed that Vmax values of general esterases hydrolyzing α-NA,α-NB and β-NA in the Daixian population were 2.15-, 1.12-, and 1.47-fold, respectively, higher than those in the Fanshi population. The AChE activity of the Fanshi population was 1.54-fold higher than that of the Daixian population. Kinetic analysis of AChE showed that significant differences were presented between the two populations in the Km values; and the Vmax value in the Fanshi population was higher than that in the Daixian population. Inhibition studies of AChE indicated that AChE from the Daixian population was 2.56-, 2.80-, and 2.29-fold less sensitive to inhibition by paraoxon, chlorpyrifos-oxon, and demeton-S-methyl, respectively, than that from the Fanshi population. These biochemical characterizations of general esterases and AChE were consistent with malathion bioassay in the two populations. It is inferred that the reduced sensitivity of altered AChE and increased general esterase activities play an important role in the differences of insusceptibility of Oxya chinensis to malathion between the two populations.  相似文献   

3.
在黄鳝二价染色体上, 运用地高辛配基标记的随机引物原位DNA合成技术诱导出了明暗相间、基本稳定且类似于R带的带状结构。本文对该结果进行了较详细的分析和讨论。 Abstract:The dark bands alternating with light bands,relatively stable and R-band-like structure was showed on the pachytene bivalents of Rics-field eel(Monopterus albus Zuiew)by using the random-primed in situ digoxigenin-labelled DNA synthesis technique,and the results were analysed and discussed in detail.  相似文献   

4.
李奎  余其兴  赵则春  余梅  周荣家 《遗传》1996,18(4):32-35
在黄鳝二价染色体上, 运用地高辛配基标记的随机引物原位DNA合成技术诱导出了明暗相间、基本稳定且类似于R带的带状结构。本文对该结果进行了较详细的分析和讨论。 Abstract:The dark bands alternating with light bands,relatively stable and R-band-like structure was showed on the pachytene bivalents of Rics-field eel(Monopterus albus Zuiew)by using the random-primed in situ digoxigenin-labelled DNA synthesis technique,and the results were analysed and discussed in detail.  相似文献   

5.
中国稻蝗属细胞分类学研究(英文)   总被引:4,自引:0,他引:4  
本文对分布于中国境内11省区,27个采集地点的八种稻蝗进行了染色体C带核型比较研究。结果表明:中华稻蝗Oxya chinensis,上海稻蝗O.shanghaiensis,无齿稻蝗O.adentata C带分布型式相似,但染色体分组型式、交叉定位数据以及异染色质含量具有差异;山稻蝗O.agauisa具有本身独特的带纹结构,与本属其它种类迥异;双带稻蝗O.bicingula染色体带型结构相似于山稻蝗及中华稻蝗类群,表明三者在进化历程中有一定联系。小稻蝗O.hyla intricata中一个亲缘种团(Sibling species group),体现在种内的形态差异及染色体带型结构的不同。显示该种近期内分化速率较高。据此,本文讨论了稻蝗属内八个种相互间的亲缘关系和分类地位,本文认为稻蝗属内务物种进化速率是不均衡的,这种状态应归因于各物种的遗传背景和环境因素的影响。  相似文献   

6.
Leaves of 407 individuals of Reaumuria soongorica (Pall.) Maxim. collected from the major distribution areas were measured to investigate the distribution characteristics of the stable carbon isotope in this desert plant, as well as correlations between δ13C values and environmental factors. Results showed that δ13C values in R. soongorica ranged from-22.77‰. to-29.85‰. and that the mean δ13C value (-26.52‰)was higher than a previously reported δ13C value for a different desert ecosystem. This indicates that R.soongorica belongs to the C3 photosynthetic pathway and has higher water use efficiency than other species. The correlations between δ13C values and environmental factors demonstrated that the foliar δ13C values in R. soongorica increased significantly with decreasing mean annual precipitation and mean relative humidity, and decreased with decreasing duration of sunshine and evaporation. The spatial distribution trend of δ13C values in R. soongorica was not obvious and there was no significant correlation between the δ13C values and mean annual temperature. We conclude that different distribution trends in δ13C values for R. soongorica were likely caused by stomatal limitation rather than by nutrient-related changes in photosynthetic efficiency and that precipitation played an important role in the wide distribution range of R.soongorica. This pattern of δ13C values for R. soongorica reinforced that it is a super-xerophil in terms of its adaptive strategies to a desert environment.  相似文献   

7.
山稻蝗不同地域和种群染色体C带核型研究   总被引:4,自引:1,他引:3  
对我国分布的山稻蝗Oxya agavisa Tsai不同种群进行了染色体C带核型研究,并对山稻蝗武夷山种群染色体C带核型进行了深入探讨,分析了其带型特殊性及该种群与其它山稻蝗种群染色体C带核型的区别与联系。同时通过对山稻蝗与中华稻蝗Oxya chinensis(Thunberg)日本稻蝗Oxya japonica(Thunberg)的形态,分布及染色体C带核型等方面的比较,探讨了该3个种之间的进化关系,认为作稻蝗属中的大型种类,上述3个种之间有着较近的亲缘关系。染色体带型的实验结果表明,中华稻蝗为较原始的种类,而日本稻蝗和山稻蝗则可能是由原始中华稻蝗进化而来,其中日本稻蝗L2染色体的形成是由于原始中华稻蝗该染色体常染色质部分异染色质化的结果,山稻蝗L2染色体则可能是由于原始中华稻蝗该染色体近端部的臂间倒位所致。通过对武夷山山稻蝗的研究,对日本稻蝗和山稻蝗之间的近缘关系进行了分析和讨论。  相似文献   

8.
Leaves of 407 individuals of Reaumuria soongorica (Pall.) Maxim. collected from the major distribution areas were measured to investigate the distribution characteristics of the stable carbon isotope in this desert plant, as well as correlations between δ^13C values and environmental factors. Results showed that δ^13C values in R. soongorica ranged from -22.77‰ to -29.85‰ and that the mean δ^13C value (-26.52‰) was higher than a previously reported δ^13C value for a different desert ecosystem. This indicates that R. soongorica belongs to the C3 photosynthetic pathway and has higher water use efficiency than other species. The correlations between δ^13C values and environmental factors demonstrated that the foliar δ^13C values in R. soongorica increased significantly with decreasing mean annual precipitation and mean relative humidity, and decreased with decreasing duration of sunshine and evaporation. The spatial distribution trend of δ^13C values in R. soongorica was not obvious and there was no significant correlation between the δ^13C values and mean annual temperature. We conclude that different distribution trends in δ^13C values for R. soongorica were likely caused by stomatal limitation rather than by nutrient-related changes in photosynthetic efficiency and that precipitation played an important role in the wide distribution range of R. soongorica. This pattern of δ^13C values for R. soongorica reinforced that it is a super-xerophil in terms of its adaptive strategies to a desert environment.  相似文献   

9.
The characteristics of serial cross-sections of hairs collected from an adult male Japanese monkey were investigated. Cross-sections were made of five to eight pieces per hair. The shapes of the cross-sections were elliptical or rounded on the whole. The fibre indices of the sections ranged from 83 to 100. In particular, those of proximal (basal) sections were close to 100. The hair diameter was 86.4 μ at maximum and 27.2 μ at minimum. A tendency was observed for the longer hairs to have thicker diameters. The changes in thickness along the fibre shaft were slightly different in relation to hair length. The thickest point was at around the middle of the fibre in the intermediate hair, somewhat towards the top of the central part in the long hair, and somewhat towards the base in the short hair. The hair of the Japanese monkey, however, was considered to be scanty in changes along the fibre shaft in comparison with many other animals. Medullae could scarcely be seen in the short hair and in the terminal and proximal sections of all hairs. Their shapes in cross-section were not uniform and rough at the margins. The fibre-medulla indices were generally less than 30 and smaller than those of many other mammals. Pigmentary granules were observed in all sections examined. The granules were black-grey in sections of the black-grey coloured part and yellow in the yellowish sections. They were dense in distal sections and scarce in sections close to the base. The cross-sectional appearance of the thickest part of the long hair was considered to be useful for hair identification, since it was good in pigmentation and medullation and relatively small fibre index.  相似文献   

10.
栽培大麦,纤毛鹅观草,属间杂种,酯酶,过氧化物酶 ISOZYME ANALYSIS OF F5 AND BCiF4 FROM CULTIVATED BARLEY ( HORDEUM VULGARE ) ~ ROEGNERIA CILIARIS LI Wan-Ji LI Yi-Ping L1U Fang Abstract Esterase and peroxidase isozymes were analysed in the variants including 4 types, 16 lines of Fs, BC1F4 and the parents derived from cultivated barley ( Hordeum vulgare cv. Arupo) x Roegneria ciliaris (Trin.) Nevski in young roots, shoots, spikes and seeds. The zymogram patterns of esterase and peroxidase demonstrated that the 16 lines of F5 and BC1F4 had all or most bands of the cultivated barley parent cv. "Arupo", 1 to 3 bands from the male R. ciliaris, and new hybrid isozyme bands in various amount. Some bands of parent "Arupo" were lost. It suggested that the genetic substances come from R. ciliaris were stably inherited to the progenies of selfing and backcrossing, and there were some variations among the lines. There was certain relationship between isozyme variance and plant characters. Thus, in identifying the translocation lines by isozyme analysis, it would be preferable to study the various organ-specific isozymes or to trace one type of isozyme pattern in consequence.  相似文献   

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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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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   

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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   

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