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Wolbachia属共生菌的侵染是引起跳虫——白符虫兆孤雌生殖的原因。对带有正常沃尔巴克氏体菌群的白符虫兆卵和通过利福平处理剔除沃尔巴克氏体菌群的白符虫兆卵的胚胎发育进行实验观察。白符虫兆的活性卵产出3到4天后,卵体大小显著性地增大,并伴随卵体形状从球形到圆饼形的变化。这些变化在利福平处理的或者是7%自然失活的非活性卵中都没有出现。推测沃尔巴克氏体在白符虫兆卵产出后的3天之内或者3天之前的受精卵发育或胚胎发育中发挥着重要作用;同时根据目前已有的研究结果推断沃尔巴克氏体对白符虫兆卵发育可能的影响机制。 相似文献
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低旋巴蜗牛胚胎发育的初步研究 总被引:1,自引:0,他引:1
对低旋巴蜗牛( Bradybaena brevispira) 的胚胎发育过程进行了研究。在23—25 ℃气温下, 从卵产出到孵化需364 小时, 直径可增长20 倍。胚胎发育全过程可分为7 个时期: 卵裂期、囊胚期、原肠期、担轮幼虫期、面盘幼虫期、幼螺形成期和孵化期。对各期的外部特征进行了描述, 并绘制了各发育时期的形态特征图。 相似文献
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三疣梭子蟹胚胎发育早期的组织学研究 总被引:11,自引:4,他引:7
对三疣梭子蟹(Portunus trituberculatus)胚胎发育早期(卵裂至原肠胚期)进行了组织学观察。结果发现:卵排至体外约52h后开始卵裂,卵裂方式为表面卵裂,卵裂至256细胞时,胚胎发育进行了囊胚期。囊胚为实囊胚,囊胚后期,16个排成例嗽叭形的预定内胚层细胞与聚在其附近的其他细胞一起内陷形成原肠。预定内胚层细胞脱离原肠后,进行1次切向分裂,形成卵黄细胞和内胚层细胞,与此同时,胚工细胞不断分裂,产生视叶原基和胸腹原基,不久,2个胞腹原基逐渐愈合形成胸腹突。随胚胎发育,在似桥细胞带上出现大颚原基、大触角原基,随后大大触角原基与视叶原基之间的腹中线上发生口凹,在小触角原基产生后,胚肥发育进入卵内无节幼体期。 相似文献
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发头裸腹溞卵和胚胎发育形态研究 总被引:4,自引:0,他引:4
在实验室恒温条件下,观察了发头裸腹溞的卵和胚胎发育.结果表明,该种枝角类的卵是均等分裂的,并具有螺旋卵裂的特点。它的发育过程大致可分为4个阶段.其间可分若干小期。发头裸腹溞卵和胚胎发育所需时间与温度的关系十分密切,在10、20、30C时发育所需时间分别为150、47和23.5小时。对该种溞的卵的形态特点进行了讨论。 相似文献
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黑水虻作为近年来广受关注的资源昆虫,其规模化应用的基础理论研究成为热点。本文对其胚胎发育过程进行研究,利用显微镜对资源昆虫黑水虻卵孵化发育过程进行观察并拍照,对胚胎各个时期的发育时间和形态进行记录。试验发现,在32℃下,黑水虻卵的发育历期为51 h。黑水虻的胚胎发育经过卵裂期、胚盘胚带形成期、原肠形成期、胚体分节期、体壁形成期、器官形成期6个典型时期。试验对孵化过程中的15个具体发育时期的特征和发育时间进行记录,形成了一套虫卵镜检技术应用于实际生产。在生产上,通过镜检技术对每一批次待孵化虫卵进行镜检观察,可初步判定该批次待孵化虫卵所处的发育阶段和死亡率,预估虫卵孵化时间和孵化率,为规模化稳定培育黑水虻苗种提供理论依据。 相似文献
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通过对6种藓类植物,即褶叶青藓(Brachythecium salebrosum(Web.et Mohr.)B.S.G.)、湿地匐灯藓(Plagiomnium acutum(Lindb.)Kop.)、侧枝匐灯藓(Plagiomnium maximoviczii(Lindb.)Kop.)、大凤尾藓(Fissidensnobilis Griff.)、大羽藓(Thuidium cymbifolium(Doz.et Molk.)B.S.G.)和大灰藓(Hypnum plumaeforme Wils.)嫩茎和老茎的石蜡切片和显微观察发现,同一藓类植株的嫩茎和老茎,茎结构稳定,不同种藓类植物茎横切面具有不同特征.植物体茎横切面形状、表层细胞的层数、细胞大小和细胞壁厚薄、皮层细胞大小和形状、中轴的有无以及比例等特征可以作为藓类植物的分科分类依据之一. 相似文献
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The levels of endogenous phytohormones and respiratory rate in nine sorts of flowers such as Cymbidium faberi Rolfe, Nopalxochia ackermannii Kunth and others were investigated both at full bloom and senescence and meanwhile the effect of exogenous phytohormones on prolonging the blossoms and promoting ethylene production were tested. There is a high content of endogenous ethylene in all the long-lived flowere, about 3–16 folds higer than the short-lived ones. There is a high level of ABA at full blooming flowers of short-lived flowers, in which there is no or only some cytokinins in it, but the ratio of CTK (6BA+zeatin)/ABA is smaller(l.7). The endogenous ABA reached a much higher level at senescence in all nine sorts of flowers, so it is reasonable to consider that it is ABA which plays an important role of regulation in controlling flower's senescence. There is a much higher level of GA3 and zeatin in the long-lived flowers which is not demonstrated in the shortlived ones. The respiratory rate is one of the factors controtling the longevity of flowers, but it does not play a decided role. Application of 6BA and zeatin prolongs distinctly orchid’s longevity, however exogenous IAA through the promotive action on ethylene production, evidently extends the longevity of the flowers of the Nopalxochia ackermannii Kunth. 相似文献
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Seed germination of an aurea mutant of tomato ( Lycopersicon esculentum Mill.) is promoted by continuous irradiation with red, far-red or long-wavelength far-red (758 nm) light as well as by cyclic irradiations (5 min red or 5 min far-red/25 min darkness). Far-red light applied immediately after each red does not change the germination behaviour. Seed germination of the isogenic wild-type, cv. UC-105, is promoted by continuous and cyclic red light while it is inhibited by continuous and cyclic far-red light and by continious 758 nm irradiation. Far-red irradiation reverses almost completely the promoting effect of red light. The promoting effect (in the aurea mutant) and the inhibitory effect (in the wild-type) of continuous far-red light do not show photon fluence rate dependency above 20 nmol m−2 s−1 . It is concluded that phytochrome controls tomato seed germination throgh low energy responses in both the wild type and the au mutant. The promoting effect of continuous and cyclic far-red light in the au mutant can be attributed to a greater sensitivity to Pfr . 相似文献
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龙胆科药用植物化学成分的研究现状 总被引:16,自引:0,他引:16
龙胆科植物在我国的分布范围很广,且多数为药用植物,其多数种属的药用植物,至今其化学成分尚未被系统研究。综述了目前龙胆科药用植物的化学成分的研究现状及一般提取方法,对近年来发现的环烯醚萜及裂环烯醚萜类化合物进行了总结,为本科药用植物的更深入研究提供了参考。 相似文献
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Shinjiro Ogita Hamako Sasamoto Edward C. Yeung Trevor A. Thorpe 《In vitro cellular & developmental biology. Plant》2001,37(2):268-273
Summary Embryogenic tissues of sugi (Cryptomeria japonica) were induced on a modified Campbell and Durzan (CD) medium containing 1 μM 2,4-dichlorophenoxyacetic acid (2,4-D) and 600 mg l−1 glutamine, and subcultured in the medium of the same composition for over 1 yr. This resulted in a mixed culture of embryogenic
and non-embryogenic cells. When embryogenic cells were isolated and cultured independently, their capacity to form embryogenic
aggregates was lost. Thus, the non-embryogenic cells present within a mixed culture system were essential to the formation
of embryogenic aggregates. When embryogenic tissues were isolated and cultured independently on a high glutamine-containing
(2400 mg l−1) medium, dry weights and endogenous levels of glutamine increased, and the tissue could generate a large number of embryogenic
aggregates. Amino acid analysis of embryogenic and non-embryogenic cells from the maintenance culture indicated a higher level
of glutamine was present in the latter. The high endogenous level of glutamine in the non-embryogenic portion of mixed cell
masses may be the supplier of glutamine for maintaining the embryogenic property of the tissues. 相似文献
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E. V. Rozengart N. E. Basova A. A. Suvorov 《Journal of Evolutionary Biochemistry and Physiology》2009,45(1):27-36
The review deals with study of enzymologic properties of a novel highly specific acetylcholinesterase substrate, N-(β-acetoxyethyl) piperidinium iodomethylate (“piperidylcholine”), and its 30 derivatives that were tested as effectors of cholinesterases of mammals and various species of Pacific squids. It was proven for the first time that responsible for specificity of action was structure of cyclic ammonium grouping of the alcohol part of molecule of the ester substrate. Analysis of specificity is performed based on enzymatic hydrolysis parameters—activity of catalytic center of cholinesterases and bimolecular constant of the reaction rate that are determined at optimal and low substrate concentrations. Among the specially synthesized group of thioester compounds there is revealed one more highly specific acetylcholinesterase substrate—N-(β-acetoxyethyl) piperidinium. 相似文献
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M. V. Kozlov V. V. Urnysheva L. N. Shishkina 《Journal of Evolutionary Biochemistry and Physiology》2008,44(4):470-475
A complex analysis of seasonal fluctuations of the mean group parameters of the system of regulation of lipid peroxidation has been performed in liver of Balb/c mice. Association of lipid characteristics and morphophysiological parameters is studied in the Balb/c mouse liver. An inter-connection is revealed between the liver index and the amount of lysoforms of phospholipids, the scale and character of the interconnection differing essentially depending on proportion of phos-phatidylcholine in mouse liver phospholipids. 相似文献
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真菌类遗传学分析的知识结构教学 总被引:5,自引:2,他引:3
本文以认知结构理论为指导,讨论了真菌类遗传分析与高等动植物遗传分析的内在联系,认为利用这种内在联系进行教学可收到好的效果并说明了作者的具体教学过程。
Abstract:In the paper, the relationship between genetic analysis of Fungi and genetic analysis of high animal and plant was discussed.A good results were obtained when we adopted this method in the teaching. 相似文献