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Martin M. Gossner Jan-Frederic Struwe Sarah Sturm Simeon Max Michelle McCutcheon Wolfgang W. Weisser Sharon E. Zytynska 《PloS one》2016,11(2)
There is a great demand for standardising biodiversity assessments in order to allow optimal comparison across research groups. For invertebrates, pitfall or flight-interception traps are commonly used, but sampling solution differs widely between studies, which could influence the communities collected and affect sample processing (morphological or genetic). We assessed arthropod communities with flight-interception traps using three commonly used sampling solutions across two forest types and two vertical strata. We first considered the effect of sampling solution and its interaction with forest type, vertical stratum, and position of sampling jar at the trap on sample condition and community composition. We found that samples collected in copper sulphate were more mouldy and fragmented relative to other solutions which might impair morphological identification, but condition depended on forest type, trap type and the position of the jar. Community composition, based on order-level identification, did not differ across sampling solutions and only varied with forest type and vertical stratum. Species richness and species-level community composition, however, differed greatly among sampling solutions. Renner solution was highly attractant for beetles and repellent for true bugs. Secondly, we tested whether sampling solution affects subsequent molecular analyses and found that DNA barcoding success was species-specific. Samples from copper sulphate produced the fewest successful DNA sequences for genetic identification, and since DNA yield or quality was not particularly reduced in these samples additional interactions between the solution and DNA must also be occurring. Our results show that the choice of sampling solution should be an important consideration in biodiversity studies. Due to the potential bias towards or against certain species by Ethanol-containing sampling solution we suggest ethylene glycol as a suitable sampling solution when genetic analysis tools are to be used and copper sulphate when focusing on morphological species identification and facing financial restrictions in biodiversity studies. 相似文献
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The watery vacuoles first described from larval insect fat body (Chironomus, Voinov, 1927; Aedes, Wigglesworth, 1942; Rhodnius, Wigglesworth, 1967) have been studied in 4th and 5th stage Calpodes larvae. The vacuoles arise at the beginning (E+6–24 hr) of the 4th stadium from plasma membrane infolds that separate from the cell surface as provacuoles less than 1 μm in diameter. These provacuoles grow and fuse with one another through the intermolt until about half the volume of each fat body cell is occupied by a single, large vacuole. The vacuoles begin to disappear at molting. Their membrane is either incorporated into the plasma membrane by exocytosis or fragmented into vesicles that fuse to become lamellar bodies where the membranes are presumably digested. All the vacuoles have gone by a few hours after ecdysis.The tyrosine content of the fat body increases and decreases in proportion to the size of the vacuoles. As the vacuoles decrease at molting the titre of tyrosine in the hemolymph is transiently elevated at the time when there is most demand for phenolics for cuticle stabilization. Crystals having the form of tyrosine crystallize out from vacuoles separated from the fat body. In fat body extracts separated by thin layer chromatography, similar crystals occur only in the eluates from spots corresponding to tyrosine. The vacuoles are therefore presumed to be tyrosine stores used in cuticle stabilization at molting. They correspond to a type of aqueous storage compartment that is well known in plants but hitherto little recognized in animal cells. 相似文献
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Summary
P. falciparum, an intraerythrocytic parasite, obtains nourishment primarily through phagocytosis of the host cytosol but also through the
incorporation of extracellular small molecules which enter through the parasitized red cell's membrane via pores. Normal mature
erythrocytes are incapable of endocytosis. Several lines of evidence suggest that extracellular large molecules may be taken
up when the mature red cell is parasitized byP. falciparum, but direct evidence has been lacking. We now report the use of ferritin, an electron dense protein, to demonstrate endocytosis
inP. falciparum infected red cells.
Parasitized red cells incubated with ferritin internalize that macromolecule as demonstrated by electron microscopy. While
normal red cells incubated with ferritin took up none of the tracer molecule, parasitized red cells internalized substantial
amounts. In addition both ferritin and apoferritin inhibited the growth ofP. falciparum in a dose dependent fashion, again indicating endocytosis of a macromolecule. These data indicate thatP. falciparum can somehow stimulate the mature erythrocyte to engage in endocytosis. We also note that both infected and non-infected red
cells in a culture in whichP. falciparum is growing become abnormally sticky for ferritin. Moreover, parasitized red cells bind I125-transferrin while non-parasitized erythrocytes do not. These observations suggest that a soluble parasite product alters
the red cell membrane in a non-global manner, causing selective effects in relation to different proteins. 相似文献
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