Post-Eclosion Temperature Effects on Insect Cuticular Hydrocarbon Profiles

© 2020 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd. The insect cuticle is the interface between internal homeostasis and the often harsh external environment. Cuticular hydrocarbons (CHCs) are key constituents of this hard cuticle and are associated with a variety of functions including stress response and communication. CHC production and deposition on the insect cuticle vary among natural populations and are affected by developmental temperature; however, little is known about CHC plasticity in response to the environment experienced following eclosion, during which time the insect cuticle undergoes several crucial changes. We targeted this crucial to important phase and studied post-eclosion temperature effects on CHC profiles in two natural populations of Drosophila melanogaster. A forty-eight hour post-eclosion exposure to three different temperatures (18, 25, and 30°C) significantly affected CHCs in both ancestral African and more recently derived North American populations of D. melanogaster. A clear shift from shorter to longer CHCs chain length was observed with increasing temperature, and the effects of post-eclosion temperature varied across populations and between sexes. The quantitative differences in CHCs were associated with variation in desiccation tolerance among populations. Surprisingly, we did not detect any significant differences in water loss rate between African and North American populations. Overall, our results demonstrate strong genetic and plasticity effects in CHC profiles in response to environmental temperatures experienced at the adult stage as well as associations with desiccation tolerance, which is crucial in understanding holometabolan responses to stress

Ambient ionization techniques

Classification, principles and application examples of the most important ambient ionization techniques were described

Mass spectrometry imaging

The course will focus on MALDI mass spectrometry imaging. Knowledge and procedures of sample preparation, matrix application, measurement, and evaluation of MALDI MSI will be summarized. The first part will be followed by a block dedicated to the practical experience of MALDI MSI of lipids,metabolites, and other analytes on tissue sections and other planar surfaces. We will also explain MSI by other ionization techniques (DESI, DAPPI, LAESI, etc.

Mass spectrometry in the analysis of non-polar compounds

Using of mass spectrometry techniques for detection of nonpolar compounds was described

Ambient ionization techniques

In the first part of the lecture definition and classification of ambient ionization techniques were described. In the next part the principles of the most important ambient ionization techniques were explained and their use was mentioned

Development of sensors based on porous silicon

5 Conclusion PS samples with defined macroporous structure were prepared and they were used as sensing layer in PL chemical sensors' concentration dependence of pL quenching response of standard PS was measured ro,ío*orogical set of linear alcohols in gas and liquid phase. From oU*'""a *tl"l"tion' of quenching sensitivity with dielecnic constant and saturated vapour it""ut" in gas and liquid phases follolrs: r. :r _L^-a io .nnrrolled bv dielectric - PL quancbing response of PS in liquid phase is controlled by streng*r ofmlYta - PL quenching response of PS in gas phase is controlled more by equilibriumconcentrationofanalýeinsideporousmatrix.Dielectric strength of analýe is not so important. PSsurfaceswerefunctionalizedwithcobaltphthalocyanine, polypyrrole, permethyl-6r-heptenoylamino-6I-deoxy B-cyclodextrins' methyl-lO-undeceonate and by oxidation' (The work is focused on using the first three compounds') We performed a measurement of concentration dependence of PL sensor response functionalized PS samples for selected organic species in gas phase' We can conclude that the PL quenching.",pň," was modiťred by functionalization of PS with selected compounds, due to change of surface polarity and molecular recognition. The magnitude of sensor response modification is dependent on kind of anallte' Another..

Temperature-programed micro-HPLC analysis of fatty acid methyl esters with APCI-MS detection

HPLC/APCI-MS analysis at microliters-per-minute flow rates was optimized for separation of fatty acid methyl esters (FAMEs). HPLC C18 column with an internal diameter of 0.3 mm and isocratic elution using 99.9 % acetonitrile and 0.1% formic acid were employed. Standard APCI ion source was suitable for detection of FAMEs at 10 μl/min flow rate with the detection limit of micrograms-per-milliliter. APCI-MS spectra with predominant [M + H]+ molecular adducts were observed. The main advantage of micro-flow measurements is the possibility of using a temperature gradient, which significantly reduces retention times of FAMEs with longer aliphatic chain. The significant reduction of solvent consumption is also an important economic and environmental advantage. The positions of double bonds in FAME chains were established using acetonitrile-related adducts and tandem mass spectrometry. The optimized method was applied for analysis of FAMEs in triacylglycerol fraction of black currant seeds oil

Desorption ionization techniques

The principles of the various desorption ionization techniques are summarized and described. Widely used techniques and their relationship with mass-spectrometric imaging are discussed in details