Protein and Ribonucleic Acid Synthesis by Plant Mitochondrial Systems

The incorporation of ¹⁴C-labelled phenylalanine into proteins of the mitochondrial systems obtained from 48-h germinating seeds of Vigna sinensis (L.) Savi can be stimulated by polyuridylic acid [poly (U)] and depressed by rifampicin, which is, however, ineffective if poly (U) is allowed to interact with the incorporating system before the antibiotic has access to it. A system consisting of a mitochondrial S-100 fraction and ribosomes from the same source with other cofactors can bring about polymerization of phenylalanine. The incorporation of ¹⁴C-labelled uracil into RNA by the plant mitochondria is greatly dependent on the exogenous addition of adenine, guanine, cytosine and also on 5-phosphoribosyl-l-pyrophosphate (5-PRPP). It is greatly suppressed by rifampicin and ethidium bromide.     

Gene flow in malaria vector Anopheles stephensi (Diptera: Culicidae) across the Aravalli Hills in North-west India

The population structure of An. stephensi in North-west India was studied to assess the impact of the Aravalli Hills, as a barrier to gene flow using microsatellite markers. Large and significant genetic differentiation was found along the sides of, as well as across, the Aravalli Hills as the mean F_ST and R_ST on west vs. east of the Aravalli Hills were 0.213, 0.112 and 0.179, 0.056, respectively. Similarly, across the hills, mean values of F_ST and R_ST were 0.100 and 0.094, respectively. Genetic diversity on both sides did not vary significantly. The F_ST values were more sensitive than R_ST values, indicating that genetic drift might have caused genetic differentiation between populations. A positive correlation (r = 0.0149 and 0.157, respective to F_ST and R_ST) was found between genetic differentiations and geographic distances irrespective of the hills. Low level of gene flow was found along both sides (Nm = 0.92 and 0.14; west vs. east of Aravalli Hills, respectively) as compared to across the Aravalli Hills (Nm = 2.25). It was found that the Aravalli Hills are not working as an effective barrier to gene flow for An. Stephensi, maybe because of the low average height and discontinuous hills, however, the distance is playing a major role for differentiation between populations due to active mode of dispersal of An. stephensi mosquitoes which have a short flight range. All this information should help draw the strategies for genetic control of mosquitoes using transgenic mosquitoes.     

基于微卫星标记的印度中部Madhya Pradesh地区疟疾强化控制和非强化控制区的斯氏按蚊基因流和种群遗传结构分析

[目的]斯氏按蚊Anopheles stephensi是亚洲东南部城市人体疟疾的主要媒介,印度12％的疟疾病例由其引起.本实验研究了印度中部Madhya Pradesh地区东北部的疟疾强化控制(EMCP)区和非强化控制(非EMCP)区斯氏按蚊的基因流.在EMCP区,由于采用了各种疟疾防控措施因而疟疾病例首先降低,但是很快回升,说明总的疟疾风险维持稳定.[方法]应用7个微卫星位点,对印度中部Madhya Pradesh地区东北部的4个EMCP区和非EMCP区采集的斯氏按蚊进行基因分型,以分析各种群参数.[结果]发现各标记在所有种群中表现出高度的多态性.在两区间未发现很大的遗传多样性.观察到EMCP区的东部种群(FST=0.0485,RST =0.1112)比非EMCP区的北部种群(FST=0.020,RST =0.0145)具有较高的遗传分化,在EMCP区和非EMCP区之间观察到较高的基因流(12.90,6.16,5.06和2.38).RST的灵敏度高于FST,说明分化可能是由于突变而非遗传漂变引起的.[结论]本研究表明,在EMCP区和非EMCP区内以及EMCP区和非EMCP区之间存在很高的基因流.基因流水平高以及抗虫性的发展似乎是EMCP区和非EMCP区疟疾病例发生增加的重要原因.     

Antifungal and Insect-Repellent Activity of Essential Oil of Zanthoxylum alatum

The essential oil of fruits of Zanthoxylum alatum (Rutaceae)proved repellent to the insect Allacophora foveicollis and fungistaticto 24 fungi, including aflatoxin-produting strains of Aspergillusflavus and A. parasiticus at a minimum dose of 2.0 x 10³ µll^–1.The fungistatic property of the oil was not affected by hightemperature, prolonged storage and increased inoculum. Essential oil, Zanthoxylum, antifungal, insect repellent     

Trifluoperazine-Sensitive Step during Sea Urchin, Echiuroid and Pelecypod Egg Activation

Trifluoperazine, a calmodulin-antagonist, is shown to inhibit egg activation by ionophore A 23187 in sea urchin (I₅₀: 43 μM), by trypsin in echiufoids (I₅₀: 22 μM) and by KCl in bivalves (I₅₀: 34 μM). In each case the inhibition could be reversed by washing the eggs and the trifluoperazine-sensitive period was clearly limited. In Barnea and Urechis , trifluoperazine inhibits calcium uptake. A common trifluoperazine-sensitive step, possibly involving calmodulin, may thus be shared by a variety of animal groups during egg activation.     

Inhibition of Anthocyanin Synthesis by Cobaltous Ions in the First Internode of Sorghum bicolor L. Moench

Cobaltous ions (Co²⁺) inhibited light-mediated anthocyanin synthesisin excised first internodes of Sorghum bicolor (L.) Moench.Studies with precursors/intermediates of the anthocyanin biosyntheticpathway, such as acetate, phenylalanine, t-cinnamic acid, tyrosine,and p-coumaric acid were undertaken to identify the metabolicsite at which Co²⁺ ions inhibit anthocyanin synthesis. p-Coumaricacid partially restored anthocyanin synthesis. No other intermediatewas effective in bringing about recovery. It is suggested thatCo²⁺ might interfere with process/es which leads to the formationof p-coumaric acid, an intermediate of the anthocyanin biosyntheticpathway. Key words: Sorghum bicolor (L.) Moench, anthocyanin, cobaltous ions, phenylalanine ammonia-lyase     

Synthesis of Mouse Haemoglobin and Globin mRNA in Leukaemic Cell Cultures

FRIEND virus infected leukaemic spleen cells, if maintained under tissue culture conditions, differentiate into erythroblasts that incorporate iron and synthesize haem^1,2. Addition of dimethyl sulphoxide (DMSO) to these tissue culture cells stimulates their differentiation along the erythrocytic line much further and results in an increased production of haemoglobin³.     

Proteins of Mitochondrial Synthesis

Proteins synthesized in vitro by mitochondria isolated from 48-h germinating seeds of Vigna sinensis (L.) Savi and incubated in the presence of ¹⁴C-labelled amino acids from Chlorella protein hydrolysate, have been found associated with nine products separable by acrylamide gel electrophoresis in the presence of sodium dodecyl sulphate. Cytoplasmic contribution to these products was practically eliminated by the use of cycloheximide. Most of the radioactivity was incorporated into proteins having molecular weights between 10,000 and 65,000 as determined by comparing their electrophoretic mobilities with those of standard, reference proteins.     

基于微卫星标记的印度中部Madhya Pradesh地区疟疾强化控制和非强化控制区的斯氏按蚊基因流和种群遗传结构分析（英文）

【目的】斯氏按蚊Anopheles stephensi是亚洲东南部城市人体疟疾的主要媒介,印度12%的疟疾病例由其引起。本实验研究了印度中部Madhya Pradesh地区东北部的疟疾强化控制(EMCP)区和非强化控制(非EMCP)区斯氏按蚊的基因流。在EMCP区,由于采用了各种疟疾防控措施因而疟疾病例首先降低,但是很快回升,说明总的疟疾风险维持稳定。【方法】应用7个微卫星位点,对印度中部Madhya Pradesh地区东北部的4个EMCP区和非EMCP区采集的斯氏按蚊进行基因分型,以分析各种群参数。【结果】发现各标记在所有种群中表现出高度的多态性。在两区间未发现很大的遗传多样性。观察到EMCP区的东部种群(FST=0.0485,RST=0.1112)比非EMCP区的北部种群(FST=0.020,RST=0.0145)具有较高的遗传分化,在EMCP区和非EMCP区之间观察到较高的基因流(12.90,6.16,5.06和2.38)。RST的灵敏度高于FST,说明分化可能是由于突变而非遗传漂变引起的。【结论】本研究表明,在EMCP区和非EMCP区内以及EMCP区和非EMCP区之间存在很高的基因流。基因流水平高以及抗虫性的发展似乎是EMCP区和非EMCP区疟疾病例发生增加的重要原因。