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991.
A rapid PCR-based method for genetically mapping ESTs 总被引:12,自引:0,他引:12
S. A. Cato R. C. Gardner J. Kent T. E. Richardson 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2001,102(2-3):296-306
A simple, semi-automatable procedure was developed for converting expressed sequence tags (ESTs) into mappable genetic markers.
The polymerase chain reaction is used to amplify regions immediately 5′ or 3′ to the coding regions of genes in order to maximise
sequence variability between alleles. Fragment length and nucleotide substitution polymorphisms among amplified alleles can
be detected using either ethidium bromide staining or automated laser-based fluorescence. A 6% non-denaturing acrylamide gel,
analysed with an ABI 377 DNA sequencer, proved capable of resolving homoduplexes and heteroduplexes formed between amplified
alleles containing nucleotide substitutions as well as resolving allelic length differences. With this approach 75% of 60
ESTs from a range of Pinus species could be genetically mapped in each of three pedigrees from P. radiata and P. taeda. Furthermore, three or four alleles were detected in each pedigree for 42% of the EST markers.
Received: 4 January 2000 / Accepted: 26 May 2000 相似文献
992.
A comparative study of molecular and morphological methods of describing relationships between perennial ryegrass (Lolium perenne L.) varieties 总被引:9,自引:0,他引:9
I. Roldán-Ruiz F.A. van Euwijk T. J. Gilliland P. Dubreuil C. Dillmann J. Lallemand M. De Loose C. P. Baril 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2001,103(8):1138-1150
A sample set of registered perennial ryegrass varieties was used to compare how morphological characterisation and AFLP® (AFLP® is a registered trademark of Keygene N.V.) and STS molecular markers described variety relationships. All the varieties were confirmed as morphologically distinct, and both the STS and AFLP markers exposed sufficient genetic diversity to differentiate these registered ryegrass varieties. Distances obtained by each of the approaches were compared, with special attention given to the coincidences and divergences between the methods. When correlations between morphological, AFLP and STS distances were calculated and the corresponding scatter-plots constructed, the variety relationships appeared to be rather inconsistent across the methods, especially between morphology and the molecular markers. However, some consistencies were found for closely related material. An implication could be that these molecular-marker techniques, while not yet suited to certain operations in the traditional registration of new varieties, could be suitable methods for investigating disputable distinctness situations or possible EDV (EDV= essentially derived variety. An EDV is a variety being clearly distinct from, but conforming in the expression of the essential characteristics of, an ’initial variety’ (IV) from which it is found to have been predominantly derived) relationships, subject to establishing standardised protocols and statistical techniques. Some suggestions for such a protocol, including a statistical test for distinctness, are given. 相似文献
993.
B. Heidenreich K. Mayer H. Sandermann Jr & D. Ernst 《Plant, cell & environment》2001,24(11):1227-1234
Mercuric‐ion‐induced gene expression was studied in Arabidopsis thaliana Columbia wild type. Rosettes of plants grown for 21 d on agar medium supplemented with 20, 30 and 40 µm HgCl2 were pooled and used to isolate cDNAs of induced genes by suppression subtractive hybridization. Of the 576 clones isolated initially, 31 turned out to be mercury‐induced by Northern hybridization. However, kinetic studies using cDNA arrays clearly showed that seven genes were exclusively mercuric‐ion‐induced, 14 were induced by mercury but also affected by a diurnal rhythm, and 10 clones were only modulated by the day–night cycle. The expression levels of the metal‐induced genes increased from 1·5‐fold to 10‐fold. Functional classification resulted in genes encoding proteins for the photosynthetic apparatus and for the antioxidative system. In addition, unexpected genes, whose connection to mercury ion stress is not evident, were identified. 相似文献
994.
Minoru S. H. Ko 《Trends in biotechnology》2001,19(12):511-518
Fundamental questions in developmental biology are: what genes are expressed, where and when they are expressed, what is the level of expression and how are these programs changed by the functional and structural alteration of genes? These questions have been addressed by studying one gene at a time, but a new research field that handles many genes in parallel is emerging. The methodology is at the interface of large-scale genomics approaches and developmental biology. Genomics needs developmental biology because one of the goals of genomics – collection and analysis of all genes in an organism – cannot be completed without working on embryonic tissues in which many genes are uniquely expressed. However, developmental biology needs genomics – the high-throughput approaches of genomics generate information about genes and pathways that can give an integrated view of complex processes. This article discusses these new approaches and their applications to mammalian developmental biology. 相似文献
995.
996.
997.
F. S. Vilim V. Alexeeva L. L. Moroz L. Li T. P. Moroz J. V. Sweedler K. R. Weiss 《Peptides》2001,22(12)
The cDNA sequence encoding the CP2 neuropeptide precursor is identified and encodes a single copy of the neuropeptide that is flanked by appropriate processing sites. The distribution of the CP2 precursor mRNA is described and matches the CP2-like immunoreactivity described previously. Single cell RT-PCR independently confirms the presence of CP2 precursor mRNA in selected neurons. MALDI-TOF MS is used to identify additional peptides derived from the CP2 precursor in neuronal somata and nerves, suggesting that the CP2 precursor may give rise to additional bioactive neuropeptides. 相似文献
998.
999.
家蝇cDNA文库的构建 总被引:10,自引:0,他引:10
自Boman小组 (Steiner ,1981)从惜古比天蚕(Hyalophoracecropia)中分离、纯化出第一种抗菌肽天蚕素以来 ,人们已在昆虫和其他无脊椎动物中发现了 170多种抗菌肽 (Lowenbergeretal ,1999)。目前 ,人们不仅搞清楚了多数抗菌肽的氨基酸序列、结构和功能特点 ,而且还对一些抗菌肽的基因进行了克隆 (陈留存和王金星 ,1999)。我们以家蝇为材料 ,分离、纯化出了抗菌肽 ,在此基础上 ,构建了经过诱导的家蝇cDNA文库 ,以克隆其基因。1 材料和方法1 1 实验材料家蝇 (Muscadomestica)… 相似文献
1000.
Gas Exchange and Epidermal Characteristics of Miscanthus Populations in Taiwan Varying with Habitats and Nitrogen Application 总被引:1,自引:0,他引:1
Seventeen clones of C4 grass Miscanthus spp. collected from different climatic regions and elevations of Taiwan were transplanted in pots. 15–16 months after collection the plants received 0, 1, and 2 g of nitrogen fertiliser (N0, N1, and N2, respectively) per pot. All the measurements were done 10–12 d after N application. The relationships between net photosynthetic rate (P
N) and photon flux density (PFD) showed a saturated curve, with PFD saturation at about 1 000 µmol m–2 s–1. The ranges of PFD saturated P
N (P
sat) for all the tested clones with N0, N1, and N2 were 8–16, 11–18, and 12–21 µmol m–2 s–1, respectively. The clones from southern Taiwan, a tropical region, showed the highest P
sat, followed by the clones from northern Taiwan, a subtropical region, while those from mountainous area showed the lowest P
sat. The clones collected from southern Taiwan showed the highest frequency of stomata on the adaxial surface, and those collected from the high mountainous area showed the lowest frequency. Also the adaxial surface of leaves from the higher mountainous area had more wax deposited than the leaves from the lowland. Thus the low P
sat in mountain clones is limited by both stomatal and non-stomatal factors. Further, the lower leaf conductance and different epidermal characteristics of mountain clones might prevent excessive loss of heat through transpiration and provide production against ultraviolet-B radiation. 相似文献