全文获取类型
收费全文 | 133篇 |
免费 | 9篇 |
国内免费 | 3篇 |
专业分类
系统科学 | 1篇 |
丛书文集 | 4篇 |
教育与普及 | 3篇 |
现状及发展 | 50篇 |
综合类 | 84篇 |
自然研究 | 3篇 |
出版年
2023年 | 3篇 |
2021年 | 1篇 |
2020年 | 3篇 |
2019年 | 1篇 |
2017年 | 2篇 |
2016年 | 2篇 |
2015年 | 1篇 |
2014年 | 3篇 |
2013年 | 2篇 |
2012年 | 6篇 |
2011年 | 4篇 |
2010年 | 1篇 |
2009年 | 7篇 |
2008年 | 1篇 |
2007年 | 4篇 |
2006年 | 9篇 |
2005年 | 7篇 |
2004年 | 4篇 |
2003年 | 2篇 |
2002年 | 4篇 |
2001年 | 2篇 |
2000年 | 9篇 |
1999年 | 4篇 |
1998年 | 4篇 |
1995年 | 7篇 |
1994年 | 4篇 |
1993年 | 9篇 |
1992年 | 4篇 |
1990年 | 4篇 |
1989年 | 3篇 |
1988年 | 4篇 |
1987年 | 1篇 |
1986年 | 4篇 |
1985年 | 17篇 |
1984年 | 2篇 |
排序方式: 共有145条查询结果,搜索用时 296 毫秒
1.
The use of anti-5-methylcytosine antibodies in affinity columns allowed the identification of methylated sequences in the
genome of Drosophila melanogaster adults. In view of the presence of transposable elements amongst the identified sequences, it has been suggested that DNA
methylation is involved in transposon control in the fly genome. On the contrary, a reanalysis of these data furnishes several
intriguing elements that could raise new questions about the role that DNA methylation plays in the fly genome. The aim of
the present paper is to discuss some features that emerge from the analysis of the identified methylated sequences.
Received 26 January 2006; received after revision 8 May 2006; accepted 2 June 2006 相似文献
2.
实验采用电生理微电极胞内记录技术,研究了果蝇三龄幼虫腹纵肌细胞的静息电位与微兴奋性接点电位、神经-肌肉兴奋性接点电位的特点。研究结果显示:1、果蝇三龄幼虫的静息电位为-53±5mV2.微兴奋性接点电位的波形与正常兴奋性接点电位相同,平均值为0.6mV.3.兴奋性接点电位在不同的刺激强度下有不同的值。 相似文献
3.
U. Graf 《Cellular and molecular life sciences : CMLS》1995,51(2):168-173
The relationship between the induction of mutant clones and the time of mutagen treatment was studied in the somatic mutation and recombination test (SMART) in wing cells ofDrosophila melanogaster. Larvae trans-heterozygous for the recessive marker mutations multiple wing hairs (mwh) and flare (flr) were produced. Batches of these larvae were then treated with mutagen at different ages spanning all three larval instars. Methyl methanesulfonate was fed acutely for 2 h by immersing the larvae in a solution of the mutagen mixed with powdered cellulose. Wings of the surviving adult flies were mounted and scored for the presence of spots. The frequency and size of single and twin spots were recorded separately. Twin spots are produced exclusively by mitotic recombination, whereas single spots can results from various types of mutational and exchange events. There exists a clear correlation between time of induction and frequency as well as size of the single spots. In young larvae only few but very large spots are induced, whereas in older larvae the frequencies are considerably increased but the sizes are smaller. The twin spots show a different relationship. Practically no twin spots are found in very young and in very old larvae. The results demonstrate that in the wing spot test the optimal age of the larvae for mutagen treatment is 72 h. 相似文献
4.
李祥龙 《河北科技师范学院学报》1993,(3)
本文以果蝇的红白眼色为遗传标记性状,利用红眼雄蝇与白眼雌蝇杂交的方法,研究了乙烯雌酚影响果蝇性比的机制。研究结果表明,在本试验浓度条件下,乙烯雌酚未能使y类型的合子发生性反转,而是对其存在致死作用或是降低了含y染色体的精子的受精机会。 相似文献
5.
Sexual isolation betweenDrosophila melanogaster females andD. simulans males. Male mating propensities versus success in hybridization 总被引:1,自引:0,他引:1
J. A. Jamart M. C. Carracedo P. Casares 《Cellular and molecular life sciences : CMLS》1993,49(6-7):596-598
Genetic variation has been found in males of aD. simulans population for their eagerness to hybridize withD. melanogaster females. In a search for traits involved in this hybridization, males ofD. simulans were tested for mating speed and sexual vigour. Between-male differences were detected in both sexual traits, but no relationship was noticed between them, nor with the frequency of hybridization. Thus male mating propensities appear to be unrelated to the breakdown of sexual isolation between these sibling species. 相似文献
6.
L. A. García-Alonso 《Cellular and molecular life sciences : CMLS》1999,55(11):1386-1398
The peripheral sensory system of the Drosophila adult has been used for the genetic analysis of axon guidance because of its accessibility for experimental manipulation
and mutant screens. Wing, leg, antenna, or eye sensory axons are able to pathfind normally under different perturbations,
indicating that sensory axon guidance is a highly canalized process. Similarly to other model systems, sensory growth cones
seem to use multiple, simultaneous cues for guidance. In addition, sensory axons from peripheral structures seem to be capable
of using alternative substrates for pathfinding. Developmental regulation could account for the high stability of axon guidance
under experimental and natural perturbation conditions. Despite this flexibility, functional characterization of genes involved
in sensory axon guidance is being carried out in situations where there appears to be less system redundancy. 相似文献
7.
Summary Supernumerary chromosomes have been detected in the karyotype ofD.n. albomicana. Their number varies from one to three. They are the smallest elements in the karyotype. Karyotypes ofD.n. albomicana with and without supernumerary chromosomes have been presented. 相似文献
8.
H. Engeln J. Krause E. Wachmann W. Köhler 《Cellular and molecular life sciences : CMLS》1985,41(5):611-612
Summary The ultrastructure of the compound eyes of several photonegative selection lines and their unselected photopositive controls of five species of themelanogaster subgroup was analyzed. A qualitative phenotypic change concerning the rhabdomeres in one of the photonegative selection lines ofD. mauritiana could be detected. It was proved that this structural aberration of the rhabdomeres is caused by a parallel mutation of the mutantora (outer rhabdomeres absent) ofD. melanogaster. 相似文献
9.
Summary Recently discovered individuals in New Zealand of the North American speciesDrosophila pseudoobscura were analyzed for any divergence in mating behavior. Cultures collected from five localities in North American were mated with a stock from Rotorua, New Zealand. No significant divergence was obtained in any of the within North Americ, and more importantly, between North American and New Zealand mating experiments. Further analyses also showed no development of sterility between recently caught New Zealand and North American flies. We discuss our results in relation to others of this type.Publication No. 5 from the Evolutionary Genetics Laboratory, University of Auckland.Acknowledgements. We thank the University Grants Committee, grant No. 140Z88, for financial assistance. We thank D.G. Futch., L. Barr, A. Beckenach and H. Spencer for their kind assistance in sending us wild caught cultures. 相似文献
10.
通过低温(18℃)培养方法,成功地建立了黑腹果蝇DNA修复功能缺陷型细胞系。该细胞系的特点是只能进行开放培养而不能进行封闭培养,为研究真核生物细胞DNA修复机理提供了一个有用的实验材料。 相似文献