No abstract

Facilitative carbohydrate transporters (GLUTs, SLC2 gene family) are transmembrane proteins transporting hexoses and other sugars based on cellular metabolic demands. While a direct link between GLUTs and metabolic disorders has framed them as important biological and medicinal targets, targeting disease-relevant GLUTs remains challenging. In this study, we aimed to identify substrate–GLUT interactions that would discriminate between major fructose transporters. We examined the uptake distribution for conformational and configurational isomers of fructose using the corresponding conformationally locked fluorescently labeled mimetics as probes for assessing GLUT preferences in real time. Through comparative analysis of the uptake of the probes in the yeast-based single GLUT expression systems and the multi-GLUT mammalian cell environment, we established the ability of fructose transporters to discriminate between fructose conformers and epimers. We demonstrated that recreating the conformational and configurational mixture of fructose with molecular probes allows for the specific probe distribution, with fructofuranose mimetic being taken up preferentially through GLUT5 and β-d-fructopyranose mimetic passing through GLUT2. The uptake of α-d-fructopyranose mimetic was found to be independent of GLUT5 or GLUT2. The results of this study provide a new approach to analyzing GLUT5 and GLUT2 activity in live cells, and the findings can be used as a proof-of-concept for multi-GLUT activity screening in live cells. The research also provides new knowledge on substrate–GLUT interactions and new tools for monitoring alterations in GLUT activities.

The aim of this study was to determine the Wolbachia infection prevalence among Drosophila species that are common in Ukraine. Methods. The total of 203 imago, representatives of seven Drosophila species collected from seven localities in Ukraine were screened for Wolbachia via PCR assay. Results. We found Wolbachia infection only in one individual of Drosophila testacea that was collected in the Chornobyl Exclusion Zone. Conclusions. In Ukraine, the examined Drosophila species are characterised by a low prevalence of Wolbachia infection. This research, together with previously reported infections in D. melanogaster and D. simulans populations, indicate that Wolbachia infects 3 out of 9 Drosophila species surveyed in Ukraine.

Aim. The study was performed to investigate the relationship between Wolbachia infection and phenotypes that distinct from wild-type of Drosophila melanogaster from different localities in Ukraine including those from Chornobyl Exclusion Zone during 2013–2014. Methods. We have established isofemale lines from populations: Uman’, Inkerman, Odesa, Varva, Kyiv, Drogobych, Yaniv, Poliske, Chornobyl, and Chornobyl Nuclear Power Plant (NPP). The ambient radiation (µSv/h) was measured in the sample sites. The flies were reared in the laboratory through two generations. We carried out the observation of F2 flies for visibly detectable phenotypes. According to whether the trait was inherited, observations were separated into three categories: with deviations of posterior cross-vein (C2) (incomplete penetrance), visible phenotypic changes (non-inherited) and mutations (inherited). Polymerase chain reaction (PCR) with primers specific to the 16S rRNA and Wolbachia surface protein (wsp) genes were used to determine infection presence in isofemale lines of the flies established for each population. Results. Examination of different phenotypes indicates that the highest mutation rate (but not C2 and not inherited changes) is in populations from Chornobyl Exclusion Zone and, therefore, connection with ambient radiation was detected (p = 0.0241). Generalized mixed linear regression has shown evidence that the presence of phenotypes with defects of C2 vein varies with endosymbiont infection presence (p = 0.03473) in the populations from radioactively polluted areas. Conclusion. Wolbachia is not related to occurring phenotypes neither with phenotypic changes nor with mutations, at least in surveyed populations. However, C2 defected phenotypes relates to the bacterial presence in populations from the contaminated area. Nonetheless, the origin of this relationship is unknown and the mechanisms of such a connection require further research. Keywords: Drosophila melanogaster, Wolbachia, endosymbiont, ambient radiation, mutation, phenotypic change, posterior cross-vein.

Aim. To investigate the potential influence of climate parameters on the rate of Wolbachia genotypes frequencies in the population of D. melanogaster from Uman' for the last seven years. Methods. We have surveyed Wolbachia infection status for isofemale lines from Uman' collected during summer -fall 2013 and 2015-2017 using polymerase chain reaction (PCR) with primers specific to the 16S rRNA and wsp (Wolbachia surface protein) genes. To determine wMel and wMelCS genotypes of Wolbachia, we have conducted PCR using polymorphic markers for the presence of the insertion sequence IS5 in WD1310 locus and the copy number of minisatellite repeats in VNTR-141 locus. Infection status of flies for 2011, 2012 and 2014 years was included from our previous studies. Data of climate factors (average seasonal temperature, dew point, and precipitation) for winter and summer of each year were obtained from weather database. Statistical analysis of Wolbachia genotypes-climate factors interaction was carried out in R version 3.5.0 using multiple linear model regression. Results. We have observed the decline of Wolbachia presence in Uman' locality and prevalence of wMel bacteria variant. Moreover, our study documented the low persistence of rare wMelCS genotype through seven years in Uman'. wMelCS frequency has been driven by the combined influence of the average temperature and humidity in summer (p = 0.03662, R^2 = 0.9995). Conclusions. The climate variability affects frequency of wMelCS genotype of Wolbachia in the D. melanogaster natural population from Uman'.