Nitrogen and Ergosterol Concentrations Varied in Live Jack Pine Phloem Following Inoculations With Fungal Associates of Mountain Pine Beetle.

Bark beetles form symbiotic associations with multiple species of fungi that supplement their metabolic needs. However, the relative contributions of each symbiont to the nutrition of bark beetles have been largely unexplored. Thus, we evaluated the ability of three fungal symbionts of mountain pine beetle to concentrate nitrogen and produce ergosterol while infecting phloem of a novel host jack pine. Ergosterol was used as proxy to determine the fungal biomass (hyphal density) in the current study. We inoculated 80 trees in two forest stands with one of the three fungal species or a non-fungal (control) agar. Six weeks later, we collected phloem from the necrotic lesions induced by the fungi, uninfected tissues adjacent to lesions, and non-inoculated control trees. We found that nutritional contributions varied with fungal species. Nitrogen in lesions was higher in trees inoculated with Ophiostoma montium or control trees, relative to Grosmannia clavigera or Leptographium longiclavatum. Furthermore, concentrations of ergosterol were higher in O. montium lesions compared to other tissues or treatments. These results suggest that O. montium differs from G. clavigera and L. longiclavatum in terms of acquiring nitrogen from host tissues and producing ergosterol.

Mechanisms and consequences of flight polyphenisms in an outbreaking bark beetle species.

Flight polyphenisms naturally occur as discrete or continuous traits in insects. Discrete flight polyphenisms include winged and wingless morphs, whereas continuous flight polyphenisms can take the form of short- or long-distance fliers. The mountain pine beetle (Dendroctonus ponderosae) exhibits polyphenic variation in flight distance but the consequences of this flight variation on life history strategies of beetles is unknown. This study assessed the effect of flight on two particular aspects of beetle biology: (1) an energetic trade-off between flight distance and host colonisation capacity; and (2) the relationship between flight distance and pheromone production. A 23 h flight treatment was applied to a subset of beetles using computer-linked flight mills. After flight treatment, both flown and unflown (control) beetles were given the opportunity to colonise bolts of host trees, and beetles that entered hosts were aerated to collect pheromone. A trade-off occurred between initiation of host colonisation and percentage body mass lost during flight, which indicates energy use during flight affects host acceptance in female mountain pine beetles. Furthermore, production of the aggregation pheromone trans-verbenol by female beetles was influenced by both percentage body mass lost during flight and flight distance. Male production of exo-brevicomin was affected by beetle condition following flight but not by the energy used during flight. These novel results give new insight into the polyphenic flight behaviour of mountain pine beetles. Flight variation is adaptive by acting to maintain population levels through safe and risky host colonisation strategies. These findings suggest mechanisms that facilitate the extremities of the continuous flight polyphenism spectrum. These opposing mechanisms appear to maintain the high variation in flight exhibited by this species.

The Urinary Metabolome of Healthy Newborns.

The knowledge of normal metabolite values for neonates is key to establishing robust cut-off values to diagnose diseases, to predict the occurrence of new diseases, to monitor a neonate's metabolism, or to assess their general health status. For full term-newborns, many reference biochemical values are available for blood, serum, plasma and cerebrospinal fluid. However, there is a surprising lack of information about normal urine concentration values for a large number of important metabolites in neonates. In the present work, we used targeted tandem mass spectrometry (MS/MS)-based metabolomic assays to identify and quantify 136 metabolites of biomedical interest in the urine from 48 healthy, full-term term neonates, collected in the first 24 h of life. In addition to this experimental study, we performed a literature review (covering the past eight years and over 500 papers) to update the references values in the Human Metabolome Database/Urine Metabolome Database (HMDB/UMDB). Notably, 86 of the experimentally measured urinary metabolites are being reported in neonates/infants for the first time and another 20 metabolites are being reported in human urine for the first time ever. Sex differences were found for 15 metabolites. The literature review allowed us to identify another 78 urinary metabolites with concentration data. As a result, reference concentration values and ranges for 378 neonatal urinary metabolites are now publicly accessible via the HMDB.