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New molecular resources regarding the so-called “non-standard models” in biology extend the present knowledge and are essential for molecular evolution and diversity studies (especially during the development) and evolutionary inferences about these zoological groups, or more practically for their fruitful management. Sepia officinalis, an economically important cephalopod species, is emerging as a new lophotrochozoan developmental model. We developed a large set of expressed sequence tags (ESTs) from embryonic stages of S. officinalis, yielding 19,780 non-redundant sequences (NRS). Around 75% of these sequences have no homologs in existing available databases. This set is the first developmental ESTs library in cephalopods. By exploring these NRS for tubulin, a generic protein family, and reflectin, a cephalopod specific protein family,we point out for both families a striking molecular diversity in S. officinalis. 相似文献
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Clark MS Worland MR 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》2008,178(8):917-933
Insects vary considerably in their ability to survive low temperatures. The tractability of these organisms to experimentation
has lead to considerable physiology-based work investigating both the variability between species and the actual mechanisms
themselves. This has highlighted a range of strategies including freeze tolerance, freeze avoidance, protective dehydration
and rapid cold hardening, which are often associated with the production of specific chemicals such as antifreezes and polyol
cryoprotectants. But we are still far from identifying the critical elements behind over-wintering success and how some species
can regularly survive temperatures below −20°C. Molecular biology is the most recent tool to be added to the insect physiologist’s
armoury. With the public availability of the genome sequence of model insects such as Drosophila and the production of custom-made molecular resources, such as EST libraries and microarrays, we are now in a position to
start dissecting the molecular mechanisms behind some of these well-characterised physiological responses. This review aims
to provide a state-of-the-art snapshot of the molecular work currently being conducted into insect cold tolerance and the
very interesting preliminary results from such studies, which provide great promise for the future. 相似文献
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在构建内蒙古阿尔巴斯白绒山羊次级毛囊兴盛期皮肤组织cDNA文库的基础上,随机挑取636个克隆从5’端开始测序,对序列进行特征分析。分析结果表明有41个ESTs与绵羊KAP6-1基因同源性大于95%,且期望值小于1e-10,进一步分析可被分为6个Qusters。从每个Cluster中挑取一个全长cDNA序列,其核苷酸序列和预测编码的蛋白质序列表明AY310753与绵羊KAP6-1最为相似、AY310750差别最大,AY310751和AY310752在编码区分别缺少36个的核苷酸或12个的氨基酸。 相似文献
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T. C. Fischer J. T. Klattig A. Gierl 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2001,103(6-7):1014-1021
The investigation of plant cytochrome P450 genes and enzymes is a field of growing interest. Apparently, an even greater diversity
of cytochrome P450 genes exists in plants in comparison to other eukaryotes. This may be due to their role in the biosynthesis
of secondary metabolites that are present in plants in an enormous variety. Most cloning approaches are hampered by the large
sequence diversity of plant cytochrome P450 genes. We present a method to clone divergent cytochrome P450 ESTs by a nested
RT-PCR-strategy. These ESTs were used for the subsequent cloning of the corresponding full-size cDNAs of divergent families
via cDNA-library screening. Sixteen cytochrome P450 genes belonging to different cytochrome P450-families have been identified
in this way, proving the efficacy of the strategy.
Received: 1 December 2000 / Accepted: 26 February 2001 相似文献
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L. S. Lima K. P. Gramacho A. S. Gesteira U. V. Lopes F. A. Gaiotto H. A. Zaidan J. L. Pires J. C. M. Cascardo F. Micheli 《Molecular breeding : new strategies in plant improvement》2008,22(2):315-318
Theobroma cacao L.–Moniliophthora perniciosa expressed sequence tags (ESTs) were converted into useful satellite markers for population analysis and genetic mapping.
Forty-nine flanking primer pairs from TSH1188 (a resistant genotype) and Catongo (a susceptible genotype) ESTs were designed
and screened for polymorphism analysis. Eleven were polymorphic, with an average of 3.81 alleles per locus and a total of
42 alleles. The satellite markers were tested on 21 cacao accessions and two bulked DNAs generated from 6 resistant and 6
susceptible plants from a segregating F2 (SCA6 × ICS1) population for witches’ broom resistance. These results show that EST-derived microsatellites (short sequence
repeats, SSRs) in Theobroma cacao have many potential applications in linkage mapping and the planning of crosses. 相似文献
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Yazawa R Yasuike M Leong J von Schalburg KR Cooper GA Beetz-Sargent M Robb A Davidson WS Jones SR Koop BF 《Marine biotechnology (New York, N.Y.)》2008,10(6):741-749
Nuclear deoxyribonucleic acid sequences from approximately 15,000 salmon louse expressed sequence tags (ESTs), the complete
mitochondrial genome (16,148bp) of salmon louse, and 16S ribosomal ribonucleic acid (rRNA) and cytochrome oxidase subunit
I (COI) genes from 68 salmon lice collected from Japan, Alaska, and western Canada support a Pacific lineage of Lepeophtheirus salmonis that is distinct from that occurring in the Atlantic Ocean. On average, nuclear genes are 3.2% different, the complete mitochondrial
genome is 7.1% different, and 16S rRNA and COI genes are 4.2% and 6.1% different, respectively. Reduced genetic diversity within the Pacific form of L. salmonis is consistent with an introduction into the Pacific from the Atlantic Ocean. The level of divergence is consistent with the
hypothesis that the Pacific form of L. salmonis coevolved with Pacific salmon (Onchorhynchus spp.) and the Atlantic form coevolved with Atlantic salmonids (Salmo spp.) independently for the last 2.5–11 million years. The level of genetic divergence coincides with the opportunity for
migration of fish between the Atlantic and Pacific Ocean basins via the Arctic Ocean with the opening of the Bering Strait,
approximately 5 million years ago. The genetic differences may help explain apparent differences in pathogenicity and environmental
sensitivity documented for the Atlantic and Pacific forms of L. salmonis.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献