Search results for "Insect Science"
showing 10 items of 1011 documents
Cops and robbers: putative evolution of copper oxygen-binding proteins.
2000
Two closely related copper proteins, phenoloxidase and haemocyanin, are known to be involved in different physiological functions such as the primary immune response and oxygen transport. Although the proteins differ structurally, they have the same active site by which dioxygen is bound. Recent results reveal that haemocyanin also exhibits phenoloxidase activity. A scenario is proposed for the evolutionary relationships among copper oxygen-binding proteins (COPs).
Hypoxia induces a complex response of globin expression in zebrafish (Danio rerio).
2006
SUMMARY Unlike most mammals, many fish species live and survive in environments with low or changing levels of oxygen. Respiratory proteins like hemoglobin or myoglobin bind or store oxygen, thus enhancing its availability to the respiratory chain in the mitochondria. Here we investigate by means of quantitative real-time PCR the changes of hemoglobin, myoglobin, neuroglobin,cytoglobin and globin X mRNA in zebrafish (Danio rerio) exposed to mild (PO2=∼8.6 kPa) or severe(PO2=∼4.1 kPa) hypoxia. Neuroglobin and myoglobin protein levels were investigated by western blotting. Whereas mild hypoxia caused only minor changes of mRNA levels, strong hypoxia enhanced mRNA levels of the control genes (…
Biosilicification of loricate choanoflagellate: organic composition of the nanotubular siliceous costal strips of Stephanoeca diplocostata.
2010
SUMMARY Loricate choanoflagellates (unicellular, eukaryotic flagellates; phylum Choanozoa) synthesize a basket-like siliceous lorica reinforced by costal strips (diameter of approximately 100 nm and length of 3 μm). In the present study, the composition of these siliceous costal strips is described, using Stephanoeca diplocostata as a model. Analyses by energy-dispersive X-ray spectroscopy (EDX), coupled with transmission electron microscopy (TEM), indicate that the costal strips comprise inorganic and organic components. The organic, proteinaceous scaffold contained one major polypeptide of mass 14 kDa that reacted with wheat germ agglutinin. Polyclonal antibodies were raised that allowed …
Separation by FPLC chromatofocusing of UDP-glucosyltransferases from three developmental stages of Drosophila melanogaster.
1997
Variation of UDP-glucosyltransferase activity, during Drosophila melanogaster development, was analyzed. The endogenous metabolite xanthurenic acid and the xenobiotic compounds 1-naphthol and 2-naphthol were used as substrates. Developmentally regulated differences were observed for the three substrates, suggesting the presence of UDP-glucosyltransferase isoenzymes. This was further confirmed by FPLC chromatofocusing on a Mono P column: seven peaks of UDP-glucosyltransferase activity (pHs: ≥6.3, 5.8, 5.5, 4.9, 4.5, 4.2, ≤4.0) with either single or overlapping substrate specificity were detected. A single xanthurenic acid:UDP-glucosyltransferase activity (pl 5.8) was found throughout develop…
ATP distribution and localization of mitochondria in Suberites domuncula (Olivi 1792) tissue
2011
SUMMARY The metabolic energy state of sponge tissue in vivo is largely unknown. Quantitative bioluminescence-based imaging was used to analyze the ATP distribution of Suberites domuncula (Olivi 1792) tissue, in relation to differences between the cortex and the medulla. This method provides a quantitative picture of the ATP distribution closely reflecting the in vivo situation. The obtained data suggest that the highest ATP content occurs around channels in the sponge medulla. HPLC reverse-phase C-18, used for measurement of ATP content, established a value of 1.62 μmol ATP g–1 dry mass in sponge medulla, as opposed to 0.04 μmol ATP g–1 dry mass in the cortex, thus indicating a specific and…
What is the function of neuroglobin?
2009
SUMMARY For a long time, haemoglobin and myoglobin had been assumed to represent the only globin types of vertebrates. In 2000, however, we discovered a third globin type by mining the genome sequence data. Based on a preferential expression in the nervous system, this globin is referred to as neuroglobin. Despite nine years of research, its function is still uncertain and a number of hypotheses have been put forward. Neuroglobin enhances cell viability under hypoxia and under various types of oxidative stress in transgenic systems, but does not appear to be strongly upregulated in response to stress. A close phylogenetic relationship with invertebrate nerve globins and its positive correla…
Studies on the laboratory mating habits of the mosquito Culex pipiens
2009
SYNOPSIS The variation in copulatory activity in three strains of Culex pipiens is investigated and the results are discussed in relation to genetic control of mosquito populations.
The effects of short-term glyphosate-based herbicide exposure on insect gene expression profiles
2023
Glyphosate-based herbicides (GBHs) are the most frequently used herbicides worldwide. The use of GBHs is intended to tackle weeds, but GBHs have been shown to affect the life-history traits and antioxidant defense system of invertebrates found in agroecosystems. Thus far, the effects of GBHs on detoxification pathways among invertebrates have not been sufficiently investigated. We performed two different experiments—1) the direct pure glyphosate and GBH treatment, and 2) the indirect GBH experiment via food—to examine the possible effects of environmentally relevant GBH levels on the survival of the Colorado potato beetle (Leptinotarsa decemlineata) and the expression profiles of their deto…
Honeybee (Apis mellifera) vision can discriminate between and recognise images of human faces.
2005
SUMMARY Recognising individuals using facial cues is an important ability. There is evidence that the mammalian brain may have specialised neural circuitry for face recognition tasks, although some recent work questions these findings. Thus, to understand if recognising human faces does require species-specific neural processing, it is important to know if non-human animals might be able to solve this difficult spatial task. Honeybees (Apis mellifera) were tested to evaluate whether an animal with no evolutionary history for discriminating between humanoid faces may be able to learn this task. Using differential conditioning, individual bees were trained to visit target face stimuli and to …
Cadmium effects on development and reproduction of Oncopeltus fasciatus (Heteroptera: Lygaeidae)
2004
Newly hatched nymphs of the insect Oncopeltus fasciatus were exposed to various concentrations of CdCl2 administered in drinking water until the end of adult life. Significant nymphal mortalities were observed at concentrations above 30 mg Cd/l (corresponding to the LC50). The duration of the nymphal stages increased in proportion to the Cd concentration; at the lowest Cd concentration of 10 mg Cd/l, the median duration was significantly prolonged by one day, while at the highest concentration of 100 mg Cd/l it was increased by 10 days over the control group. The weight of newly emerged adults lineally decreased with Cd concentration, being reduced to half the weight of controls at 100 mg C…