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Evgen'ev MB Zatsepina OG Garbuz D Lerman DN Velikodvorskaya V Zelentsova E Feder ME 《Chromosoma》2004,113(5):223-232
To investigate the genetic basis of differing thermotolerance in the closely related species Drosophila virilis and Drosophila lummei, which replace one another along a latitudinal cline, we characterized the hsp70 gene cluster in multiple strains of both species. In both species, all hsp70 copies cluster in a single chromosomal locus, 29C1, and each cluster includes two hsp70 genes arranged as an inverted pair, the ancestral condition. The total number of hsp70 copies is maximally seven in the more thermotolerant D. virilis and five in the less tolerant D. lummei, with some strains of each species exhibiting lower copy numbers. Thus, maximum hsp70 copy number corresponds to hsp70 mRNA and Hsp70 protein levels reported previously and the size of heat-induced puffs at 29C1. The nucleotide sequence and spacing of the hsp70 copies are consistent with tandem duplication of the hsp70 genes in a common ancestor of D. virilis and D. lummei followed by loss of hsp70 genes in D. lummei. These and other data for hsp70 in Drosophila suggest that evolutionary adaptation has repeatedly modified hsp70 copy number by several different genetic mechanisms. 相似文献
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We analyzed nucleotide variation in the hsp70 genes of Drosophila melanogaster (five genes) and D. simulans (four genes) to characterize the homogenizing and diversifying roles of gene conversion in their evolution. Gene conversion
within and between the 87A7 and 87C1 gene clusters homogenize the hsp70 coding regions; in both D. melanogaster and D. simulans, same-cluster paralogues are virtually identical, and large intercluster conversion tracts diminish 87A7/87C1 divergence.
Same-cluster paralogues share many polymorphisms, consistent with frequent intracluster conversion. Shared polymorphism is
highly biased toward silent variation; homogenizing conversion interacts with purifying selection. In contrast to the coding
regions, some hsp70 flanking regions show conversion-mediated diversification. Strong reductions of nucleotide variability and linkage disequilibria
among conversion-mediated sites in hsp70Ab and hsp70Bb alleles sampled from a single natural population are consistent with a selective sweep. Comparison of the D. melanogaster and D. simulans hsp70 genes reveals whole-family fixed differences, consistent with rapid propagation of novel mutations among duplicate genes.
These results suggest that the homogenizing and diversifying roles of conversion interact to drive dynamic concerted evolution
of the hsp70 genes.
Received: 25 June 2001 / Accepted: 10 October 2001 相似文献
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Adam Chen Elizabeth F. Kramer Lauren Purpura Jennifer L. Krill Troy Zars Ken Dawson-Scully 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》2011,197(12):1113-1118
Poikilothermic organisms such as insects have mechanisms to protect neural function under high temperature stress. Natural
variation at the foraging (for) locus of the fruit fly, Drosophila melanogaster, encoding a cGMP-dependent protein kinase (PKG), influences neural thermotolerance in Drosophila larvae. The current study re-examines thermotolerance of adult flies to account for inconsistencies in the documented role
of for during hyperthermia. We found that adult for
R
(rover) flies with high PKG activity were incapacitated faster under hyperthermic conditions of 39°C compared to their lower PKG
activity counterparts for
s
and for
s2
(sitters), but not at higher temperatures. This indicates that lowered PKG activity promotes tolerance to heat stress, and that the
for gene influences thermotolerance for a narrow range of temperatures in adult flies. 相似文献
6.
The cherry slugworm Caliroa cerasi is a significant destructive pest of sour cherries (Prunus cerasus) in Turkey. The potential of entomopathogenic fungi for controlling C. cerasi was evaluated. The effects of exposure methods and conidial concentrations (1 × 106, 1.5 × 106, 1 × 107 and 1.5 × 107 conidia/ml) on mature larvae of C. cerasi infected by Beauveria bassiana were investigated under laboratory conditions. Larvae sprayed directly with B. bassiana conidial suspensions and larvae exposed to B. bassiana-treated leaves resulted in 100% mortality within 2.90 and 2.77 days, respectively. The median lethal time (LT50) and days to mortality were highest in the 1.0 × 107 concentrations of conidia for both direct spray and leaf exposure. The present study suggests that B. bassiana has good potential for control of the cherry slugworm, C. cerasi. 相似文献
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Campoletis chlorideae Uchida (Hymenoptera: Ichneumonidae) is an important solitary larval endoparasitoid of the tomato fruit borer Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) in India. The interaction between Bacillus thuringiensis subspecies kurstaki (Btk) HD-1 and C. chlorideae was studied under laboratory condition to explore their compatibility in managing H. armigera. The results had indicated that the growth and development of H. armigera was affected in a dose-dependent manner upon feeding on sublethal doses of Btk HD-1-treated diets. There were no larval survivors in lethal doses of Btk HD-1 (LC70 and LC90). The growth and survival of the parasitoid were normal when the host larvae were fed with sublethal doses or subjected to
short time exposure to lethal doses of Btk HD-1. However, the parasitoid offsprings developed slowly and pupal as well as adult period, adult weight and adult emergence
rate were reduced significantly if the parasitoid was developing inside a severely Bt intoxicated host larvae. There were no evident differences in longevity of parasitoid adults that were fed on honey solution
containing different concentrations of Btk HD-1 as compared to adults fed only on honey solution. This indicates no direct adverse effect of Btk HD-1 on C. chlorideae. Further, the gravid female parasitoid did not discriminate Btk HD-1 intoxicated and normal H. armigera larvae for oviposition. The result implies that spore crystal formulation of Btk HD-1 can be effectively used in a synergistic manner along with existing natural or prereleased population of C. chlorideae in organic farming or as components in biointensive IPM module for managing H. armigera. 相似文献
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Twenty-three isolates of Metarhizium anisopliae (Metschnikoff) Sokorin and three isolates of Beauveria bassiana (Balsamo) Vuillemin (Ascomycota: Hypocreales: Clavicipitaceae) were assessed for their virulence against the two-spotted
spider mite, Tetranychus urticae Koch (Acari: Tetranychidae). Based on the screening results, nine isolates of M. anisopliae and two isolates of B. bassiana were tested for their virulence against young adult (1- to 2-day-old) female T. urticae at constant temperatures of 20, 25, 30 and 35°C. At all temperatures tested, all the fungal isolates were pathogenic to T. urticae but mortality varied with isolates and temperatures. Fungal isolates were more virulent at 25, 30 and 35°C than at 20°C.
The lethal time to 50% mortality (LT50) and lethal time to 90% mortality (LT90) values decreased with increased temperature. There were no significant differences in virulence between fungal isolates
at 30 and 35°C; however, significant differences were observed at 20 and 25°C. 相似文献
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Fawzeia H. Elmhalli Katinka Pålsson Jan Örberg Thomas G. T. Jaenson 《Experimental & applied acarology》2009,48(3):251-262
The toxicity of para-menthane-3,8-diol (PMD), the main arthropod-repellent compound in the oil of the lemon eucalyptus, Corymbia citriodora, was evaluated against nymphs of Ixodes ricinus using five methods (A–E) of a contact toxicity bioassay. Mortality rates were estimated by recording numbers of dead nymphs
at 30 min intervals during the first 5 h after the start of exposure and at longer intervals thereafter. The mortality rate
increased with increasing concentration of PMD and duration of exposure with a distinct effect after 3.5 h. From the results
obtained by methods A, C and E, the LC50 range was 0.035–0.037 mg PMD/cm2 and the LC95 range was 0.095–0.097 mg PMD/cm2 at 4 h of exposure; the LT50 range was 2.1–2.8 h and the LT95 range was 3.9–4.2 h at 0.1 mg PMD/cm2. To determine the duration of toxic activity of PMD, different concentrations (0.002, 0.01, 0.1 mg PMD/cm2) were tested and mortality was recorded at each concentration after 1 h; thereafter new ticks were tested. This test revealed
that the lethal activity of PMD remained for 24 h but appeared absent after 48 h. The overall results show that PMD is toxic
to nymphs of I. ricinus and may be useful for tick control. 相似文献
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L. N. Chuvakova F. S. Sharko A. V. Nedoluzhko A. A. Polilov E. B. Prokhorchuk K. G. Skryabin M. B. Evgen’ev 《Molecular Biology》2017,51(4):543-548
Miniaturization is an evolutionary process that is widely represented in both invertebrates and vertebrates. Miniaturization frequently affects not only the size of the organism and its constituent cells, but also changes the genome structure and functioning. The structure of the main heat shock genes (hsp70 and hsp83) was studied in one of the smallest insects, the Megaphragma amalphitanum (Hymenoptera: Trichogrammatidae) parasitic wasp, which is comparable in size with unicellular organisms. An analysis of the sequenced genome has detected six genes that relate to the hsp70 family, some of which are apparently induced upon heat shock. Both induced and constitutively expressed hsp70 genes contain a large number of introns, which is not typical for the genes of this family. Moreover, none of the found genes form clusters, and they are all very heterogeneous (individual copies are only 75–85% identical), which indicates the absence of gene conversion, which provides the identity of genes of this family in Drosophila and other organisms. Two hsp83 genes, one of which contains an intron, have also been found in the M. amalphitanum genome. 相似文献
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Analía Alvarez Eduardo G. Virla Licia M. Pera Mario D. Baigorí 《World journal of microbiology & biotechnology》2011,27(10):2343-2349
Two Bacillus thuringiensis strains isolated from diseased Spodoptera frugiperda larvae collected in the northwest of Argentina were molecularly and phenotypically characterized. Insecticidal activity against
Spodoptera frugiperda larvae was also determined. Both strains were highly toxic against first instar larvae. One strain (Bacillus thuringiensis LSM) was found to be even more toxic than the reference strain Bacillus thuringiensis var. kurstaki 4D1. This strong biological effect was represented by both a higher mortality which reached 90%, and a shorter LT50. Molecular characterization showed that Bacillus thuringiensis LSM carried a cry gene profile identical to that of Bacillus thuringiensis var. kurstaki 4D1. Evaluation of length polymorphism of the intergenic transcribed spacers between the 16S and 23S rDNA genes revealed
an identical pattern between native strains and Bacillus thuringiensis var. kurstaki 4D1. In contrast, phenotypic characterization allowed differentiation among the isolates by means of their extracellular
esterase profiles. Lytic activity that would contribute to Bacillus thuringiensis effectiveness was also studied in both strains. Analyses like those presented in the current study are essential to identify
the most toxic strains and to allow the exploitation of local biodiversity for its application in biological control programmes. 相似文献
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Seventeen isolates of Metarhizium anisopliae (Metschnikoff) Sorokin and two isolates of Beauveria bassiana (Balsamo) Vuillemin were evaluated for their pathogenicity against the tobacco spider mite, Tetranychus evansi Baker & Pritchard. In the laboratory all the fungal isolates were pathogenic to the adult female mites, causing mortality between 22.1 and 82.6%. Isolates causing more than 70% mortality were subjected to dose–response mortality bioassays. The lethal concentration causing 50% mortality (LC50) values ranged between 0.7×107 and 2.5×107 conidia ml−1. The lethal time to 50% mortality (LT50) values of the most active isolates of B. bassiana and M. anisopliae strains varied between 4.6 and 5.8 days. Potted tomato plants were artificially infested with T. evansi and treated with B. bassiana isolate GPK and M. anisopliae isolate ICIPE78. Both fungal isolates reduced the population density of mites as compared to untreated controls. However, conidia formulated in oil outperformed the ones formulated in water. This study demonstrates the prospects of pathogenic fungi for the management of T. evansi. 相似文献
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Healy TM Schulte PM 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》2012,182(1):49-62
We characterized the degree of plasticity in thermal tolerance (assessed as critical thermal maxima; CTMax) and the relationship
between thermal tolerance and underlying physiological and biochemical factors in two subspecies of a teleost fish, Fundulus heteroclitus. CTMax was not affected by repeated daily heat shock, but increased within a few days in response to warm acclimation. Loss
of tolerance with acclimation to lowered temperatures occurred more slowly. Exposure to hypoxia decreased CTMax, and hyperoxia
had no effect. CTMax showed a daily rhythm in both subspecies. Thermal acclimation changed the value of CTMax but did not
affect the amplitude of the rhythm. Exposure to altered photoperiod had complex effects with a summer photoperiod producing
a daily rhythm at higher CTMax than a spring photoperiod, and a winter photoperiod removing the rhythm. There was no daily
rhythm in routine metabolic rate in either subspecies. There was no relationship between CTMax and the protein levels of the
constitutive 70 and 90 kDa heat shock proteins (HSC70, HSP90β) in gill, or with mRNA levels of hsc70 in liver. There was a daily rhythm in the basal levels of the inducible hsp70-2 mRNA. Induction of hsp70-2 mRNA with mild heat shock occurred only in the evening and at night, and not during the day. These results demonstrate that
there is substantial plasticity of thermal tolerance in killifish, and that this plasticity does not differ between subspecies.
CTMax has a complex relationship with physiological and biochemical mechanisms that have been hypothesized to affect thermal
tolerance. 相似文献
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Li-Rong Yang Xiao Qiang Bao-Qin Zhang Mei-Jun Tang Chuan-Xi Zhang 《Journal of microbiology (Seoul, Korea)》2009,47(2):208-213
The tea slug moth Iragoidae fasciata (Lepidoptera, Eucleidae) is one of the main insect pests that attack tea bushes. A new nucleopolyhedrovirus (NPV) called
Iragoidae fasciata NPV (IrfaNPV) was recently isolated from diseased larvae. An 11,626 bp fragment of the viral genomic DNA containing the polyhedrin gene and other 12 genes was cloned and sequenced. Gene comparison and phylogenetic analysis showed that IrfaNPV is a member
of the Group I NPVs. However, the genomic organization of IrfaNPV is highly distinct. In addition, electron microscopy analysis
showed that IrfaNPV is a single nucleocapsid NPV (SNPV). An inoculation assay showed that IrfaNPV is semi-permissive in the
Trichoplusia ni cell line Tn-5Bl-4. Bioassays on lethal concentration (LC50) and lethal time (LT50) were conducted to test the susceptibility of I. fasciata larvae to the virus. 相似文献
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Keoagile W. Modisakeng Meesbah Jiwaji Eva-Rachele Pesce Jacques Robert Chris T. Amemiya Rosemary A. Dorrington Gregory L. Blatch 《Molecular genetics and genomics : MGG》2009,282(2):185-196
Molecular chaperones facilitate the correct folding of other proteins, and heat shock proteins form one of the major classes
of molecular chaperones. Heat shock protein 70 (Hsp70) has been extensively studied, and shown to be critically important
for cellular protein homeostasis in almost all prokaryotic and eukaryotic systems studied to date. Since there have been very
limited studies conducted on coelacanth chaperones, the main objective of this study was to genetically and biochemically
characterize a coelacanth Hsp70. We have successfully isolated an Indonesian coelacanth (L. menadoensis) hsp70 gene, Lmhsp70, and found that it contained an intronless coding region and a potential upstream regulatory region. Lmhsp70 encoded a typical Hsp70 based on conserved structural and functional features, and the predicted upstream regulatory region
was found to contain six potential promoter elements, and three potential heat shock elements (HSEs). The intronless nature
of the coding region and the presence of HSEs suggested that Lmhsp70 was stress-inducible. Phylogenetic analyses provided further evidence that Lmhsp70 was probably inducible, and that it branched as a clade intermediate between bony fish and tetrapods. Recombinant LmHsp70
was successfully overproduced, purified and found to be functional using ATPase activity assays. Taken together, these data
provide evidence for the first time that the coelacanth encodes a functional molecular chaperone system.
K. W. Modisakeng and M. Jiwaji contributed equally to this study. 相似文献
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In the yeast Saccharomyces cerevisiae, the molecular chaperone HSP26 has the remarkable ability to sense increases in temperature directly and can switch from
an inactive to a chaperone-active state. In this report, we analyzed the effect of expression of HSP26 in Arabidopsis thaliana plants and their response to high temperature stress. The hsp26 transgenic plants exhibited stronger growth than wild type plants at 45 °C for 16 h. The chlorophyll content and chlorophyll
fluorescence decreased much more in wild type than in transgenic plants. Moreover, the transgenic plants had higher proline
and soluble sugar contents, and lower relative electrical conductivity and malondialdehyde contents after high temperature
stress. Furthermore, we found that over-expression of HSP26 in Arabidopsis increased the amount of free proline, elevated the expression of proline biosynthetic pathway genes and therefore enhanced
Arabidopsis tolerance to heat stress. 相似文献
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Surface inoculation dose–response and time–response bioassays and detached fruit bioassays were conducted with a novel South
African isolate of the Cryptophlebia leucotreta granulovirus (CrleGV-SA) against Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Noctuidae) neonate larvae. LC50 and LC90 values were estimated to be 4.095 × 103 and 1.185 × 105 OBs ml−1, respectively. LT50 and LT90 values were estimated to be 4 days 22 h and 7 days 8 h, respectively, categorising the virus as a fast or type 2 granulovirus.
There was a conspicuous difference in behaviour between larvae on inoculated diet and untreated diet, resulting in a significant
reduction in penetration of diet. Bioassays on detached Navel oranges revealed LC50 and LC90 values of 9.310 × 107 and 1.515 × 109 OBs ml−1, when using data on numbers of larvae per fruit rather than on numbers of infested fruit. Field trials will be conducted. 相似文献
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A genetic variant of the entomopathogenic fungus Metarhizium
anisopliae var. anisopliae, isolated from a soil in Alberta, Canada, from a location with a history of severe grasshopper infestations, was evaluated
for pathogenicity in bioassays of living grasshoppers. Mortality in treated individuals drawn from a laboratory colony was
99% (LT50 = 6.7 days, LT90 = 9.6 days) at 12 days post-inoculation compared to 100% (LT50 = 4.1 days, LT90 = 5.8 days) mortality at 8 days in insects exposed to a commercial isolate of M. anisopliae var. acridum (IMI 330189). Experimental infection of field-collected grasshoppers under laboratory conditions with the native isolate
of M. anisopliae var. anisopliae resulted in 100% (LT50 = 4.4 days, LT90 = 5.4 days) mortality attained within 7 days compared to 100% (LT50 = 4.7 days, LT90 = 6.3 days) mortality in 9 days in insects treated with M. anisopliae var. acridum. Amplification of fungal genomic DNA from the indigenous isolate with primers for the specific detection of M. anisopliae var. anisopliae produced a product almost 300 bp larger than expected based on previously known isolates. This is the first demonstration
of a highly virulent, indigenous non-chemical control agent of grasshoppers in North America.
GenBank Accession Nos. DQ342236, DQ342237. 相似文献