苜蓿体细胞胚胎发生过程中DNA、RNA和蛋白质的合成动态

苜蓿(Medicago sativa L.)下胚轴切段产生的愈伤组织经2,4-D短时间诱导后,在无激素液体培养基中可形成大量体细胞胚胎。经2,4-D诱导后的愈伤组织在转入无激素培养基1天后,其DNA、RNA和蛋白质的合成即进入活跃合成状态,并在体细胞胚胎发育过程中保持逐步升高的趋势。在苜蓿体细胞胚胎发生过程中,有些蛋白质组分含量减少或消失,但绝大部分蛋白质组分的含量明显增加,并且有若干新蛋白的出现,其中24 KD和46 KD蛋白质为体细胞胚胎发生早期所特有。     

体细胞胚胎发生的分子机制及生理生化研究进展

本文较详细地综述了近年来体细胞胚胎发生的分子机制及生理生化研究进展,这些研究包括：DNA、RNA和蛋白质的合成;特异性胚性蛋白的研究;内源多胺代谢的改变;内源游离氨基酸及还原性小分子物质含量的改变;内源激素的改变以及几种酶的同工酶酶谱的改变;并指出了当前体细胞胚胎发生机理及生理生化研究中存在的一些问题。     

体细胞胚胎发生的分子机制及生理生化研究进展

本文较详细地综述了近年来体细胞胚胎发生的分子机制及生理生化研究进展,这些研究色括:DNA、RNA和蛋白质的合成;特异性胚性蛋白的研究;内源多胺代谢的改变;内源游离氨基酸及还原性小分子物质含量的改变;内源激素的改变以及几种酶的同工酶酶谱的改变;并指出了当前体细胞胚眙发生机理及生理生化研究巾存在的一些问题。     

不同分化状态的白百利烟草愈伤组织在生长过程中核酸蛋白质的变化

本文报道了在正常分化芽和根、诱导芽或恨定向发生的白百利烟草(Nico-tiana tabacum Baibaili)愈伤组织在生长过程中DNA、RNA和蛋白质变化的结果。MS+0.2mg/1NAA+0.2mg/1 KT诱导白百利烟草愈伤组织正常分化出芽和根,MS+0.05mg/1NAA+2mg/1KT诱导愈防组织定向地芽发生,MS+0.5mg/1NAA+0.05mg/1KT诱导愈伤组织定向地根发生。在定向诱导芽或根发生愈伤组织里的RNA和蛋白质合成的第一个高峰出现,比正常发生芽和根的愈伤组织里DNA、RNA和蛋白质的第一个高峰迟5天,在芽发生的愈伤组织里DNA峰出现也迟5天,在根发生的愈伤组织里DNA蜂,则相同于正常分化的愈伤组织DNA峰出现。外源的植物生长物质诱导器官定向发生的作用表现在RNA水平上。在三种分化状态的愈伤组织里,蛋白质组成在第8天表现出明显的差异。41KD和46KD蛋白质在器官的定向发生中可能起着相当重要的作用。     

Changes in RNA/DNA ratio and growth of slime flounder, Microstomus achne, larvae until metamorphosis

Understanding the nutritional condition and survival of fish larvae is of primary importance in mass larva culture because intensive mortality is concentrated during the larval period. In order to estimate growth and nutritional status based on biochemical indices of slime flounder, Microstomus achne, larvae reared under starved and fed conditions in the hatchery for 58 days and the changes of RNA, DNA, and protein contents were described with the progress of growth and developmental. DNA contents increased gradually throughout the experimental period until 12 and 58 days post‐hatching (DPH) in starved and fed groups respectively. Although they fluctuated and decreased around 12 and 46 DPH, the RNA contents of the fed group increased gradually after hatching; however, in the starved group, they decreased after yolk absorption and 7 DPH. Subsequently, the RNA/DNA ratios in the starved group remained constant until 6 DPH and then decreased rapidly. In the fed group, this decreased slightly from hatching to 14 DPH, then increased gradually until the end of the experiment, except at the lower level of around 46 DPH. Namely, temperature shocks (around 14 DPH) and the dramatic changes in body shape (around 46 DPH) were accompanied by the decrease of the RNA/DNA ratios. Total protein/DNA in both groups decreased rapidly during yolk absorption 0–7 DPH, then decreased continuously until death in the starved group; in the fed group total protein/DNA increased again with feeding. It is suggested that the changes in these biochemical values reflect yolk absorption, feeding, morphogenetic changes, growth, and environmental conditions.     

Protein Turnover and Growth of the Rat Brain from the Foetus to Old Age

Growth of the rat brain was studied between 16 days of foetal life and old age (105 weeks). Developmental changes in cerebral RNA, DNA, and protein contents are described. The age-related decline in brain growth rates correlates with progressive decreases in the fractional rates of protein synthesis (from 58 to 6.8% per day) and breakdown (from 36.4 to 4.1% per day).     

莲胚发育与核酸,蛋白质含量的变化

莲胚发育达到最大鲜重(开花后21d)前,胚轴和子叶的DNA,RNA都持续增长。开花13d后,蛋白、淀粉等贮藏物质显著积累,核酸增长速度加快。成熟胚轴的DNA和RNA含量很高,而子叶中积累大量的淀粉、可溶性糖和蛋白质。发育前期胚乳的生长速度较快,开花后16d左右鲜重和物质积累达到高峰。胚生长后期胚乳逐渐败育,贮藏物质和结构物质都减少,膨大的子叶逐步取代了胚乳的地位。 莲胚生物大分子物质含量的模式属于双子叶植物类型。讨论了莲胚细胞多倍化的问题。     

平贝母体细胞胚胎发生中的核酸与蛋白质合成研究

在获得比较理想的平贝母体细胞胚胎发生体系的基础上,我们应用放射性同位素液体闪烁计数技术测定了平贝母体细胞胚胎发生过程中球形胚、心形胚、鱼雷胚、子叶胚和成熟胚等时期的DNA、RNA和蛋白质合成动态,实验表明,从球形胚到子叶胚,核酸与蛋白质的合成速度递增。在子叶胚前期RNA合成达到高峰,在子叶胚期蛋白质合成达到高峰,在子叶胚后期DNA合成达到高峰,核酸与蛋白质合成速度的变化与胚体细胞增殖及器官分化相关联。     

宁夏枸杞器官发生和体细胞胚胎发生过程中DNA,RNA和蛋白质合成动？…

After the calli originating from the leaf explant of Lycium barbarum L. were selected and proliferated, the yellowish calli with same origin, similar state were transferred to O medium or E medium and the regenerative systems of organogenesis and somatic embryogenesis might form. By these systems, a comparative study on the synthetic activities of DNA, RNA and protein in the two in vitro regeneration pathways was carried out. The results were as follows: (1) Before meristemoid and embryogenic cells were formed, the synthesis of RNA was activated firstly, followed with the increase of synthesis rates of DNA and protein. During the formation of globular embryo, the synthesis rate of DNA increased quickly and then the activities of syntheses of RNA and protein reached the peak, while it was the contrary during germination of adventitious bud. (2) Components of soluble protein changed regularly. A peptide (153.6 kD) appeared during the initiation of both organogenesis and somatic embryogenesis. Several peptides disappearing gradually in the early-stage of differentiation could regenerate with the formation of shoot primordium and globular embryo. Corresponding to morphogenesis, both regenerative systems had specific peptides (84.9 kD, 46.3 kD and 44 kD, 36.2 kD) as molecular markers of its own development. In addition, the relation and mechanism of the two regenerative systems were discussed.     

大蒜体细胞胚胎发生过程中抗氧化酶活性变化及某些生理特征

以大蒜的发芽叶基(鳞茎)为外植体诱导体细胞胚胎发生,研究大蒜体胚发生过程中SOD、POD和CAT 3种抗氧化酶的活性以及可溶性糖和可溶性蛋白质含量变化.结果表明:在大蒜体胚发生过程中,SOD、POD和CAT活性变化与胚性愈伤组织的诱导及体胚的发育密切相关,POD对体胚的诱导起主导作用,而SOD和CAT在体胚的发育和成熟中起主导作用.可溶性糖和可溶性蛋白质累积与大蒜体细胞胚胎发生密切相关.