Adult females of Aedes aegypti are facultative blood sucking insects and vectors of Dengue and yellow fever viruses. Insect dispersal plays a central role in disease transmission and the extremely high energy demand posed by flight is accomplished by a very efficient oxidative phosphorylation process, which take place within flight muscle mitochondria. These organelles play a central role in energy metabolism, interconnecting nutrient oxidation to ATP synthesis, but also represent an important site of cellular superoxide production. Given the importance of mitochondria to cell physiology, and the potential contributions of this organelle for A. aegypti biology and vectorial capacity, here, we conducted a systematic assessment of mitochondrial physiology in flight muscle of young adult A. aegypti fed exclusively with sugar. This was carried out by determining the activities of mitochondrial enzymes, the substrate preferences to sustain respiration, the mitochondrial bioenergetic efficiency and capacity, in both mitochondria-enriched preparations and mechanically permeabilized flight muscle in both sexes. We also determined the substrates preferences to promote mitochondrial superoxide generation and the main sites where it is produced within this organelle. We observed that respiration in A. aegypti mitochondria was essentially driven by complex I and glycerol 3 phosphate dehydrogenase substrates, which promoted distinct mitochondrial bioenergetic capacities, but with preserved efficiencies. Respiration mediated by proline oxidation in female mitochondria was strikingly higher than in males. Mitochondrial superoxide production was essentially mediated through proline and glycerol 3 phosphate oxidation, which took place at sites other than complex I. Finally, differences in mitochondrial superoxide production among sexes were only observed in male oxidizing glycerol 3 phosphate, exhibiting higher rates than in female. Together, these data represent a significant step towards the understanding of fundamental mitochondrial processes in A. aegypti, with potential implications for its physiology and vectorial capacity.

In the last few decades a negative association between the level of milk production and fertility has been observed. Currently, the most utilized method of measuring male fertility employed by the livestock industry is related to the Non-Return Rate (NRR). Through differential proteome analysis, this study evaluated changes in the expression of the protein profile of spermatozoa collected from 16 bulls with different levels of field fertility expressed as an estimated relative conception rate (ERCR). The main aim is to identify putative protein markers to be used as putative indices of fertility. Two dimensional electrophoresis coupled with mass spectrometry analysis was used for protein separation and identification. To improve differential proteome analysis among experimental groups, a part of shotgun MS analysis was also performed. Three protein spots showed a differential expression pattern among all ERCR classes. Alpha enolase was significantly down-regulated in the ERCR− group, while two other proteins, isocitrate dehydrogenase and triosephosphate isomerase, were up-regulated in ERCR− in comparison to ERCR+. Alpha-enolase and isocitrate dehydrogenase subunit alpha (IDH-alpha) have been described in the literature for having a potential role in bull fertility. The possibility of determining protein biomarkers for fertility is more useful and less expensive than ERCR for acquiring rapid estimation of fertility because it does not require the use of field insemination trials. Shotgun MS analysis conducted on the same samples revealed 7 proteins down-regulated in the ERCR− group and 1 protein up-regulated. Among these proteins, calmodulin, ATP synthase mitochondrial subunits alpha and delta, malate dehydrogenase and sperm equatorial segment protein 1 were shown to be linked with sperm fertility.

Drug resistance in food-borne bacterial pathogens is an almost inevitable consequence of the use of antimicrobial drugs, used either therapeutically or to avoid infections in food-producing animals. In the past decades, the spread and inappropriate use of antibiotics have caused a considerable increase of antibiotics to which bacteria have developed resistance and, moreover, bacteria are becoming resistant to more than one antibiotic simultaneously. Understanding mechanisms at the molecular level is extremely important to control multi-resistant strains and to develop new therapeutic strategies. In the present study, comparative proteomics was applied to characterize membrane and cytosolic proteome in order to investigate the regulation of protein expression in multi-resistance E. coli isolated from young never vaccinated water buffalo. Results highlighted differentially expressed proteins under multi drug resistance conditions giving new insights about mechanisms involved in resistance, as quorum sensing mechanisms, and suggesting possible novel bacterial targets to develop alternative antibiotic drugs.

Flight dispersal represents a key aspect of the evolutionary and ecological success of insects, allowing escape from predators, mating, and colonization of new niches. The huge energy demand posed by flight activity is essentially met by oxidative phosphorylation (OXPHOS) in flight muscle mitochondria. In insects, mitochondrial ATP supply and oxidant production are regulated by several factors, including the energy demand exerted by changes in adenylate balance. Indeed, adenylate directly regulates OXPHOS by targeting both chemiosmotic ATP production and the activities of specific mitochondrial enzymes. In several organisms, cytochrome c oxidase (COX) is regulated at transcriptional, post-translational, and allosteric levels, impacting mitochondrial energy metabolism, and redox balance. This review will present the concepts on how COX function contributes to flying insect biology, focusing on the existing examples in the literature where its structure and activity are regulated not only by physiological and environmental factors but also how changes in its activity impacts insect biology. We also performed in silico sequence analyses and determined the structure models of three COX subunits (IV, VIa, and VIc) from different insect species to compare with mammalian orthologs. We observed that the sequences and structure models of COXIV, COXVIa, and COXVIc were quite similar to their mammalian counterparts. Remarkably, specific substitutions to phosphomimetic amino acids at critical phosphorylation sites emerge as hallmarks on insect COX sequences, suggesting a new regulatory mechanism of COX activity. Therefore, by providing a physiological and bioenergetic framework of COX regulation in such metabolically extreme models, we hope to expand the knowledge of this critical enzyme complex and the potential consequences for insect dispersal.