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11.
Y Kimura T Hanami Y Tanaka MJ de Hoon T Soma M Harbers A Lezhava Y Hayashizaki K Usui 《Biochemistry》2012,51(31):6056-6067
Nucleic acid oligonucleotides are widely used in hybridization experiments for specific detection of complementary nucleic acid sequences. For design and application of oligonucleotides, an understanding of their thermodynamic properties is essential. Recently, exciton-controlled hybridization-sensitive fluorescent oligonucleotides (ECHOs) were developed as uniquely labeled DNA oligomers containing commonly one thymidine having two covalently linked thiazole orange dye moieties. The fluorescent signal of an ECHO is strictly hybridization-controlled, where the dye moieties have to intercalate into double-stranded DNA for signal generation. Here we analyzed the hybridization thermodynamics of ECHO/DNA duplexes, and thermodynamic parameters were obtained from melting curves of 64 ECHO/DNA duplexes measured by ultraviolet absorbance and fluorescence. Both methods demonstrated a substantial increase in duplex stability (ΔΔG°(37) ~ -2.6 ± 0.7 kcal mol(-1)) compared to that of DNA/DNA duplexes of the same sequence. With the exception of T·G mismatches, this increased stability was mostly unaffected by other mismatches in the position opposite the labeled nucleotide. A nearest neighbor model was constructed for predicting thermodynamic parameters for duplex stability. Evaluation of the nearest neighbor parameters by cross validation tests showed higher predictive reliability for the fluorescence-based than the absorbance-based parameters. Using our experimental data, a tool for predicting the thermodynamics of formation of ECHO/DNA duplexes was developed that is freely available at http://genome.gsc.riken.jp/echo/thermodynamics/ . It provides reliable thermodynamic data for using the unique features of ECHOs in fluorescence-based experiments. 相似文献
12.
Sang‐Sup SO Tae‐Hwan HWANG Waseem AKRAM Jhong‐Kyung CHOI Jong‐Jin LEE 《Entomological Research》2012,42(3):158-162
The present study relates to a methanol extract of the seed coat of Ginkgo biloba, and tested particularly on the third instar larvae of Spodoptera exigua. The extract was found to have an inhibitory effect on the growth of the larvae besides bringing a change in the nutrient reserves in the body of the insect. Topical application of five different doses of the methanol extract resulted in a mortal effect to third instar larvae of S. exigua that is very much dependent on the dose as well as duration of exposure. Lower doses revealed lower mortality after 24 h of application. At doses of 1.00, 2.00, 4.00, 8.00 and 16.00 ng/larva, mortalities were 9.25, 26.07, 50.32, 56.28 and 92.44%, respectively. The dose for 50% mortality (LD50) of methanol extracts by applied by a topical method with 1 µL of acetone solution was 1.92 ng/larva. Nutrient reserves like protein, glycogen and lipid are known to regulate pupation and adult emergence. These reserves have been found to be lower in treated larvae, indicating the insecticidal role of methanol extracts from G. biloba against third instar larvae of S. exigua. 相似文献
13.
RICLEF GROLLE MAY LING SO 《Botanical journal of the Linnean Society. Linnean Society of London》2003,142(2):229-235
Riccia fruticulosa O.F.Müll., 1782 from Norway is a valid name, referring to Riccardia palmata (Hedw.) Carruth. In 1785 Dickson misidentified British plants of a blue Metzgeria as R. fruticulosa . The European blue species of Metzgeria is conspecific with M. violacea (Ach.) Dumort., which replaces M. fruticulosa auct. The true origin of the type of Jungermannia violacea Ach., 1805 is probably Tierra del Fuego (rather than Dusky Bay, New Zealand), where the species is widespread. Reports from Australasia, Asia and Africa are all erroneous. The blue colour of Jungermanniales is found only in living plants and is derived from the oil-bodies. In contrast, that of Metzgeria appears only after death; its biological function is unknown. © 2003 The Linnean Society of London, Botanical Journal of the Linnean Society, 2003, 142 , 229−235. 相似文献
14.
Abstract. 1. Larval rearing densities of Hemipyrellia ligurriens (Wiedemann) (Diptera: Calliphoridae) in standardized carrion were manipulated in order to investigate changes in life-history parameters in response to larval competition for food.
2. Competition was of the typical scramble type. Survivorship remained high at densities up to 32 larvae g liver-1 but decreased rapidly as larval density increased further.
3. Emergent adults were undersized with reduced fecundity and longevity. Variations in adult body size apparently reduced the effects of competition on larval mortality.
4. Females of dry weight corresponding to only 10.4% of the potential maximum emerged at the highest rearing densities of 128 larvae g liver-1. However, these females had a nearly four-fold increase in reproductive investment (per unit weight) when compared to the largest individuals.
5. The duration of larval development declined when competition was intense (i.e. at high larval densities).
6. The short adult life of H.ligurriens, combined with the unpredictability of larval habitat availability, may reduce the value of long-range dispersal so that females 'do better' by maintaining reproductive investment despite a concomitant decline in dispersal ability. 相似文献
2. Competition was of the typical scramble type. Survivorship remained high at densities up to 32 larvae g liver
3. Emergent adults were undersized with reduced fecundity and longevity. Variations in adult body size apparently reduced the effects of competition on larval mortality.
4. Females of dry weight corresponding to only 10.4% of the potential maximum emerged at the highest rearing densities of 128 larvae g liver-1. However, these females had a nearly four-fold increase in reproductive investment (per unit weight) when compared to the largest individuals.
5. The duration of larval development declined when competition was intense (i.e. at high larval densities).
6. The short adult life of H.ligurriens, combined with the unpredictability of larval habitat availability, may reduce the value of long-range dispersal so that females 'do better' by maintaining reproductive investment despite a concomitant decline in dispersal ability. 相似文献
15.
Aminoacylation of fragment combinations from yeast tRNA phe 总被引:5,自引:0,他引:5
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17.
The ubiquitin-conjugating enzyme UbcM4 was previously shown to be necessary for normal mouse development. As a first step in identifying target proteins or proteins involved in the specificity of UbcM4-mediated ubiquitylation, we have isolated seven cDNAs encoding proteins that specifically interact with UbcM4 but with none of the other Ubcs tested. This interaction was observed in yeast as well as in mammalian cells. With one exception, all UbcM4-interacting proteins (UIPs) belong to a family of proteins that contain a RING finger motif. As they are structurally related to RING finger proteins that have recently been shown to play an essential role in protein ubiquitylation and degradation, the possibility is discussed that UIPs are involved in the specific recognition of substrate proteins of UbcM4. 相似文献
18.
Structure and chromosomal mapping of a highly polymorphic repetitive DNA sequence from the pseudoautosomal region of the mouse sex chromosomes 总被引:5,自引:0,他引:5
K Harbers U Francke P Soriano R Jaenisch U Müller 《Cytogenetics and cell genetics》1990,53(2-3):129-133
The pseudoautosomal region of the Mov15 mouse strain is marked by a Moloney murine leukemia provirus. The sequences flanking the Mov15 provirus were molecularly cloned and shown to consist of a tandemly repeated sequence of 31 nucleotides. Copy number variation of this repeat most likely accounts for the polymorphism in the mouse pseudoautosomal region detected with a probe from the flanking sequences. In situ hybridization to metaphase chromosomes showed heavy labeling of the pairing region of the X and Y chromosomes. The repetitive sequence was also found at the subtelomeric region of three autosomes. A similar level of amplification as the one seen on the sex chromosomes seems to be present on chromosomes 9 and 13. Lower copy number appear to be present on chromosome 4. 相似文献
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