Disruption of segmentation in a short germ insect embryo

Development ◽  
1986 ◽  
Vol 96 (1) ◽  
pp. 245-266
Author(s):  
Jane E. Mee ◽  
Vernon French
Keyword(s):  
Heat Shock ◽  
Schistocerca Gregaria ◽  
Constant Number ◽  
Segment Pattern ◽  
Different Parts

The effect of heat shock (15 min at 48 °C) on segmentation has been investigated in the short germ embryo of the locust (Schistocerca gregaria). Prior to formation of the germ anlage and at the disc stage heat shock considerably reduced the survival of eggs but appeared to have little effect upon segmentation. At later stages heat shock had no effect on survival but resulted in disruptions of the segmental pattern. The location of abnormal segments depended upon the stage at heat shock and the number affected depended on its severity. A constant number of normal segments developed between the last segment visible at the time of heat shock and the first abnormal segment. These results are similar to the disruptions observed in amphibian somites following heat shock. However, different parts of the segment pattern varied in their response; the head segments were very rarely affected, and disrupted regions rarely started in the middle abdomen (segments A5 and A6). The results are discussed in relation to two models (the clock and wavefront and progress zone models) that have been proposed as an explanation for the specification of the somite pattern in amphibians.

Disruption of segmentation in a short germ insect embryo

Development ◽  
1986 ◽  
Vol 96 (1) ◽  
pp. 267-294
Author(s):  
Jane E. Mee ◽  
Vernon French
Keyword(s):  
Heat Shock ◽  
Schistocerca Gregaria ◽  
Intercalary Regeneration ◽  
Early Embryos ◽  
Pattern Regulation ◽  
Segment Pattern

A heat shock (of 15min at 48° C) given to early embryos of the locust, Schistocerca gregaria, results in localized abnormalities in the segment pattern subsequently formed. Most defects involve two consecutive segments of the thorax or abdomen, and these are analysed in detail. The abdominal defects fall into three main classes each of which involves the absence of a particular region of the segment pair and, in one class, duplication of the region which remains. The thoracic defects similarly involve absence of parts of the segments and the formation of a single limb base from which one, two, or three limbs develop. Heat shock may result in the absence of parts of segments in two distinct ways. It may interfere with the process of segmentation or it may delete parts of already formed segment primordia. These possibilities are discussed although, at present, neither can be excluded. The duplication observed in some abdominal disruptions and the formation of triple limbs indicates that the absence of parts of embryonic segments is followed by pattern regulation similar to that occurring in regeneration studies on larval segments and appendages of other insects. Two out of the three classes of abnormality can be explained in terms of intercalary regeneration restoring pattern continuity, but it is possible that discontinuities persist in the remaining class.

FMRFamide-like peptides in the locust: distribution, partial characterization and bioactivity

1990 ◽  
Vol 149 (1) ◽  
pp. 335-360 ◽  
Author(s):  
S. Robb ◽  
P. D. Evans
Keyword(s):  
High Pressure ◽  
Nervous System ◽  
Liquid Chromatography ◽  
Nervous Tissue ◽  
Schistocerca Gregaria ◽  
Quantitative Distribution ◽  
Putative Target ◽  
Target Sites ◽  
Neuromuscular Preparation ◽  
Different Parts

The quantitative distribution of FMRFamide-like peptides in the nervous system and in their putative target sites in the locust Schistocerca gregaria is described using radioimmunoassay techniques. The nature of the immunoreactive material has been characterized by high-pressure liquid chromatography. At least six peaks of FMRFamide-like immunoreactivity can be separated in extracts of locust nervous tissue. The relative proportions of these peaks vary from tissue to tissue, suggesting a differential expression of FMRFamide-like peptides in different parts of the locust nervous system. The bioactivity of the endogenous FMRFamide-like peptides has been assessed on the extensor tibiae neuromuscular preparation and on the locust heart. The results suggest that FMRFamide-like peptides in the locust function both as circulating neurohormones and as locally released neuromodulators or neurotransmitters.

scholarly journals Heat shock proteins development in different stages of schistocerca gregaria as response to heavy metals intoxication

2011 ◽  
Vol 03 (03) ◽  
pp. 218-226
Author(s):  
Hesham A. Yousef ◽  
Amira Afify ◽  
Afaf Abdel Meguid ◽  
Hany M. Hassan
Keyword(s):  
Heavy Metals ◽  
Heat Shock ◽  
Heat Shock Proteins ◽  
Schistocerca Gregaria ◽  
Shock Proteins

Synaptic activation of efferent neuromodulatory neurones in the locust Schistocerca gregaria

1998 ◽  
Vol 201 (24) ◽  
pp. 3339-3354 ◽  
Author(s):  
S. Baudoux ◽  
M. Burrows
Keyword(s):  
Schistocerca Gregaria ◽  
The Body ◽  
Strong Correlations ◽  
Nerve Roots ◽  
Dorsal Midline ◽  
Synaptic Potentials ◽  
Metathoracic Ganglion ◽  
Dorsal Unpaired Median ◽  
Different Parts ◽  
Stimulation Of

The segmental ganglia of the locust contain efferent neuromodulatory neurones with cell bodies at the dorsal midline and axons that supply muscles and other tissue on both sides of the body. These are the dorsal unpaired median (DUM) neurones. Intracellular recordings were made from pairs of known metathoracic efferent DUM neurones in locusts in which all nerves were intact and in isolated metathoracic ganglia. The 19 metathoracic, efferent DUM neurones were identified according to the nerve roots through which their axons emerge from the ganglion. The synaptic potentials in these DUM neurones have been analysed to investigate how these neurones are activated and how their spikes are controlled. The degree of correlation between the synaptic potentials in particular pairs of neurones was quantified using a correlation analysis. This allowed the population of DUM neurones to be divided into three subsets that also map onto an anatomical grouping based on the distribution of their axons in the lateral nerves: (i) DUM1 neurones (DUMDL and DUM1b); (ii) DUM3 and DUM3,4 neurones; and (iii) DUM3,4,5, DUM5b neurones and DUMETi. Individual neurones within each subset showed strong correlations between their synaptic potentials, in both intact locusts and isolated ganglia, and tended to spike at the same time. Neurones in different subsets had few synaptic potentials in common and tended to spike independently. The persistence of common synaptic potentials in neurones of the three subsets in isolated ganglia indicates that they are derived from neurones within the metathoracic ganglion. The DUM neurones that had many common synaptic potentials in a quiescent locust responded in similar ways to mechanosensory stimulation of different parts of the body. DUM3,4, 5 and DUM5 neurones gave the clearest and most consistent responses to stimulation of mechanoreceptors on either hind leg. DUM3 and DUM3, 4 neurones responded variably, but usually with a hyperpolarisation. DUM1 neurones were rarely excited by mechanosensory stimuli but, like the preceding group, their responses were dependent upon whether the locust was moving its legs. These results lend further support to the idea that there is a subdivision of action amongst this population of DUM neurones, with those supplying the same targets being driven by the same presynaptic local neurones.

Effect of the Duration and Intensity of Heat Shock During Grain Filling on Dry Matter and Protein Accumulation, Technological Quality and Protein Composition in Bread and Durum Wheat

1997 ◽  
Vol 24 (2) ◽  
pp. 245 ◽  
Author(s):  
M. Corbellini ◽  
M.G. Canevar ◽  
L. Mazza ◽  
M. Ciaffi ◽  
D. Lafiandra ◽  
...  
Keyword(s):  
High Temperature ◽  
Heat Shock ◽  
Grain Yield ◽  
Durum Wheat ◽  
Dry Matter ◽  
Grain Filling ◽  
Protein Accumulation ◽  
Heat Shocks ◽  
Very High ◽  
Different Parts

High temperatures occurring during grain filling are known to affect wheat grain yield and quality considerably. In this paper we report the results of experiments carried out with two cultivars of bread wheat (Triticum aestivum L.) and two cultivars of durum wheat (Triticum durum Desf.). The plants, cultivated in pots, were subjected to 13 heat treatments (temperature up to 40°C) differing in duration and timing and starting 7 days after anthesis. Heat treatments were applied by temporary transfer of the pots to a glasshouse where the temperature rose to 40°C as a consequence of solar radiation for periods ranging from 5 to 30 days. The applied heat shocks substantially affected dry matter and protein accumulation in the different parts of the plant. Early heat shock (5 days with a total of 18 h of temperature in the range 35–40°C) caused a small reduction of kernel mass and no effect on protein per kernel; the damage was greater in the central and in the final stage of grain filling. Plants subjected to a progressive increase of temperature, or to an early heat shock, acquired thermotolerance to further heat shocks. Continuous exposure to very high temperatures from 27 days after pollination to maturity did not negatively affect grain yield and it facilitated the remobilisation of nitrogen from vegetative to reproductive organs. Rheological properties were severely affected by heat shocks at all stages of grain filling: 5 days of heat shock were sufficient to reduce mixing tolerance by 40–60%. These variations in rheological properties were accompanied by modification of the level of protein aggregation: soluble polymeric proteins and low molecular weight gliadins progressively increased according to the intensity of the stress, while insoluble polymeric proteins decreased. Our experiments, carried out in conditions close to the Mediterranean climate, indicate that the occurrence of very high temperature in the range 35–40°C during grain filling substantially affects dry matter and protein accumulation in the different parts of the plant. The formation of the complex protein aggregates responsible for positive dough mixing properties is significantly reduced by very high temperature. When heat shock came late in grain filling, grain yield and protein concentration were not negatively affected but a ‘dough weakening’ effect, which may reduce the commercial value of the production, is to be expected.

Fish kidney cell line in response to heat shock

1992 ◽  
Vol 50 (1) ◽  
pp. 704-705
Author(s):  
Li-Chu Tung ◽  
Yung-Reui Chen ◽  
Shiu-Nan Chen ◽  
Guang-Hsiung Kuo
Keyword(s):  
Heat Shock ◽  
Cell Line ◽  
Fetal Calf Serum ◽  
Calf Serum ◽  
Uranyl Acetate ◽  
Ultrastructural Changes ◽  
Heat Shock Treatment ◽  
Acanthopagrus Schlegeli ◽  
Cacodylate Buffer ◽  
Fish Kidney

In the present study, the ultrastructural changes of BPK cells, a fibroblast-like cell line, derived from the kidney of juvenile black porgy Acanthopagrus schlegeli, under heat shock treatment are described.The BPK cells were maintained in L-15 medium supplemented with 10% fetal calf serum and 0.15 M NaCl at 28|C2. The heating was carried out in precalibrated water baths. Monolayers of cells, grown on coverslips in parafilm-sealed petri dishes were submerged under water for 30 min at 40|C treatments. Cells were fixed in 2.5% glutaraldehyde in 0.1 M cacodylate buffer supplemented with 6.6% sucrose, postfixed in 1% OsO4 and flat embedded in Spurr’s resin. Silver section were cut parallel to the substratum, stained with uranyl acetate and Reynold’s lead citrate, and examined in a Hitachi H-600 electron microscope at 75 KV.

Absence of temporal ordering of apoptotic features in heat-shock treated leukemia and lymphoma cell lines

1996 ◽  
Vol 54 ◽  
pp. 758-759
Author(s):  
D. W. Fairbain ◽  
M.D. Standing ◽  
K.L. O'Neill
Keyword(s):  
Heat Shock ◽  
Cell Lines ◽  
Chromatin Condensation ◽  
Membrane Integrity ◽  
Resistant Cell ◽  
Membrane Blebbing ◽  
Late Loss ◽  
Induced Apoptosis ◽  
Dying Cells ◽  
In Cells

Apoptosis is a genetically defined response to physiological stimuli that results in cellular suicide. Features common to apoptotic cells include chromatin condensation, oligonucleosomal DNA fragmentation, membrane blebbing, nuclear destruction, and late loss of ability to exclude vital dyes. These characteristics contrast markedly from pathological necrosis, in which membrane integrity loss is demonstrated early, and other features of apoptosis, which allow a non-inflammatory removal of dead and dying cells, are absent. Using heat shock-induced apoptosis as a model for examining stress response in cells, we undertook to categorize a variety of human leukemias and lymphomas with regard to their response to heat shock. We were also interested in determining whether a common temporal order was followed in cells dying by apoptosis. In addition, based on our previous results, we investigated whether increasing heat load resulted in increased apoptosis, with particular interest in relatively resistant cell lines, or whether the mode of death changed from apoptosis to necrosis.

Glycyrrhizin effects rat hepatocytes via the reduction of heat shock protein 90 expression

2001 ◽  
Vol 120 (5) ◽  
pp. A357-A357
Author(s):  
T YOH ◽  
T NAKASHIMA ◽  
Y SUMIDA ◽  
Y KAKISAKA ◽  
H ISHIKAWA ◽  
...  
Keyword(s):  
Heat Shock ◽  
Heat Shock Protein ◽  
Heat Shock Protein 90 ◽  
Rat Hepatocytes
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