Drinking and Flying: Does Alcohol Consumption Affect the Flight and Echolocation Performance of Phyllostomid Bats?

Background

In the wild, frugivorous and nectarivorous bats often eat fermenting fruits and nectar, and thus may consume levels of ethanol that could induce inebriation. To understand if consumption of ethanol by bats alters their access to food and general survival requires examination of behavioural responses to its ingestion, as well as assessment of interspecific variation in those responses. We predicted that bats fed ethanol would show impaired flight and echolocation behaviour compared to bats fed control sugar water, and that there would be behavioural differences among species.

Methodology/Principal Findings

We fed wild caught Artibeus jamaicensis, A. lituratus, A. phaeotis, Carollia sowelli, Glossophaga soricina, and Sturnira lilium (Chiroptera, Phyllostomidae) sugar water (44 g of table sugar in 500 ml of water) or sugar water with ethanol before challenging them to fly through an obstacle course while we simultaneously recorded their echolocation calls. We used bat saliva, a non-invasive proxy, to measure blood ethanol concentrations ranging from 0 to >0.3% immediately before flight trials. Flight performance and echolocation behaviour were not significantly affected by consumption of ethanol, but species differed in their blood alcohol concentrations after consuming it.

Conclusions/Significance

The bats we studied display a tolerance for ethanol that could have ramifications for the adaptive radiation of frugivorous and nectarivorous bats by allowing them to use ephemeral food resources over a wide span of time. By sampling across phyllostomid genera, we show that patterns of apparent ethanol tolerance in New World bats are broad, and thus may have been an important early step in the evolution of frugivory and nectarivory in these animals.     

The genome sequence of the protostome Daphnia pulex encodes respective orthologues of a neurotrophin, a Trk and a p75NTR: Evolution of neurotrophin signaling components and related proteins in the bilateria

Background

Neurotrophins and their Trk and p75NTR receptors play an important role in the nervous system. To date, neurotrophins, Trk and p75NTR have only been found concomitantly in deuterostomes. In protostomes, homologues to either neurotrophin, Trk or p75NTR are reported but their phylogenetic relationship to deuterostome neurotrophin signaling components is unclear. Drosophila has neurotrophin homologues called Spätzles (Spz), some of which were recently renamed neurotrophins, but direct proof that these are deuterostome neurotrophin orthologues is lacking. Trks belong to the receptor tyrosine kinase (RTK) family and among RTKs, Trks and RORs are closest related. Flies lack Trks but have ROR and ROR-related proteins called NRKs playing a neurotrophic role. Mollusks have so far the most similar proteins to Trks (Lymnaea Trk and Aplysia Trkl) but the exact phylogenetic relationship of mollusk Trks to each other and to vertebrate Trks is unknown. p75NTR belongs to the tumor necrosis factor receptor (TNFR) superfamily. The divergence of the TNFR families in vertebrates has been suggested to parallel the emergence of the adaptive immune system. Only one TNFR representative, the Drosophila Wengen, has been found in protostomes. To clarify the evolution of neurotrophin signaling components in bilateria, this work analyzes the genome of the crustacean Daphnia pulex as well as new genetic data from protostomes.

Results

The Daphnia genome encodes a neurotrophin, p75NTR and Trk orthologue together with Trkl, ROR, and NRK-RTKs. Drosophila Spz1, 2, 3, 5, 6 orthologues as well as two new groups of Spz proteins (Spz7 and 8) are also found in the Daphnia genome. Searching genbank and the genomes of Capitella, Helobdella and Lottia reveals neurotrophin signaling components in other protostomes.

Conclusion

It appears that a neurotrophin, Trk and p75NTR existed at the protostome/deuterostome split. In protostomes, a "neurotrophin superfamily" includes Spzs and neurotrophins which respectively form two paralogous families. Trks and Trkl proteins also form closely related paralogous families within the protostomian RTKs, whereby Trkls are absent in deuterostomes. The finding of p75NTR in several protostomes suggests that death domain TNFR superfamily proteins appeared early in evolution.     

Aufreinigung von Fumonisinen und ihren Hydrolysaten über ein neuartiges Festphasenextraktions-Material

Tests with various clean-up materials after optimisation of different parameters showed that the use of Oasis® material resulted in matrixless chromatograms in HPLC-FLD. The selectivity and detection limit of the method was improved by using LC-MS/MS as the detection system. Mean recovery was 100%, and no negative food matrix effects could be observed.     

Genomic and population analyses of the mating type loci in Coccidioides species reveal evidence for sexual reproduction and gene acquisition

Coccidioides species, the fungi responsible for the valley fever disease, are known to reproduce asexually through the production of arthroconidia that are the infectious propagules. The possible role of sexual reproduction in the survival and dispersal of these pathogens is unexplored. To determine the potential for mating of Coccidioides, we analyzed genome sequences and identified mating type loci characteristic of heterothallic ascomycetes. Coccidioides strains contain either a MAT1-1 or a MAT1-2 idiomorph, which is 8.1 or 9 kb in length, respectively, the longest reported for any ascomycete species. These idiomorphs contain four or five genes, respectively, more than are present in the MAT loci of most ascomycetes. Along with their cDNA structures, we determined that all genes in the MAT loci are transcribed. Two genes frequently found in common sequences flanking MAT idiomorphs, APN2 and COX13, are within the MAT loci in Coccidioides, but the MAT1-1 and MAT1-2 copies have diverged dramatically from each other. Data indicate that the acquisition of these genes in the MAT loci occurred prior to the separation of Coccidioides from Uncinocarpus reesii. An analysis of 436 Coccidioides isolates from patients and the environment indicates that in both Coccidioides immitis and C. posadasii, there is a 1:1 distribution of MAT loci, as would be expected for sexually reproducing species. In addition, an analysis of isolates obtained from 11 soil samples demonstrated that at three sampling sites, strains of both mating types were present, indicating that compatible strains were in close proximity in the environment.     

CTLA-4 . FasL induces early apoptosis of activated T cells by interfering with anti-apoptotic signals

The fusion protein CTLA-4 . FasL, a paradigmatic "trans signal converter protein", can attach to APC surfaces and in effect convert B7-activating costimulator signals into inhibitory Fas receptor-generated signals. The present study investigates CTLA-4 . FasL's mechanism of action. A combination of p27(kip) and proliferating cell nuclear Ag Western blot and propidium iodide flow cytometric analysis showed no CTLA-4 . FasL effect on cell cycle entry and progression, pointing away from the kind of classical anergy associated with CTLA-4 . Ig. Significantly, CTLA-4 . FasL elicited apoptosis (as detected by annexin-V/propidium iodide costaining) as early as 24 h after T cell activation, suggesting that some coordinate signaling might be capacitating the Fas receptor. Significantly, CTLA-4 . FasL, but not CTLA-4 . Ig, anti-Fas mAb, or the two in combination, abrogated the usual increase in expression of the anti-apototic protein, cFLIP. Furthermore, activation of caspases 8 and 3 were not affected by CTLA-4 . FasL. These findings suggest a model for CTLA-4 . FasL action wherein there is coordinate triggering of a death receptor and suppression of a proapoptotic protein.     

Bestimmung von Fumonisinen in komplexen Lebensmittelmatrices mittels Accelerated Solvent Extraktion (ASE)

Accelerated solvent extraction (ASE) is an alternative sample extraction procedure for fumonisins in corn and corn products. ASE gave results comparable to that of a draft CEN method, but required less extraction time. Furthermore, ASE gave significantly higher quantitative values than another method reported for extraction of fumonisins (Trucksess et al., 1995).