Field effects of faecal residues from ivermectin slow‐release boluses on the attractiveness of cattle dung to dung beetles

A 2‐year study was performed in two sites in southern France to assess the effect of ivermectin residues on the attractiveness of cattle dung to colonizing insects. Insect captures were compared between pitfall traps baited with dung from untreated cattle and dung from cattle that had been treated with a slow‐release (SR) bolus of ivermectin. Cattle dung was collected at different times after treatment (4, 14, 42, 70 and 98 days). Excretion showed a plateau, with levels ranging between 0.688 µg and 1.123 µg ivermectin per gram of wet dung. Faecal residues affected insect captures at both sites. Effects were independent of the time dung was collected after treatment, except for one result subsequent to a severe drought during the baiting period. Ivermectin‐contaminated dung showed a significant attractive effect, with increased captures regardless of the guild to which beetles belonged. This study demonstrates the attractiveness of ivermectin residues over a long period after the treatment of animals. It draws attention to the danger of widespread use of this endectocide‐based SR bolus, which is attributable to the preferential attraction of insects to treated dung, which potentially puts at risk the survival of their offspring.     

Heritability of resistance to oxidative stress in early life

Oxidative stress has recently been suggested to play an important role in life‐history evolution, but little is known about natural variation and heritability of this physiological trait. Here, we explore phenotypic variation in resistance to oxidative stress of cross‐fostered yellow‐legged gull (Larus cachinnans) chicks. Resistance to oxidative stress was not related to plasma antioxidants at hatching, which are mostly derived from maternal investment into eggs. Common environmental effects on phenotypic variation in resistance to oxidative stress were not significant. Heritability was relatively low and nonsignificant in hatchlings, but interestingly, the chicks of age 8 days showed high and significant heritability (h² = 0.59). Our results suggest that resistance to oxidative stress is determined mainly by the genotype as chicks grow. Further work is required to explore the genetic role of oxidative stress in life‐history evolution.     

Development of High‐Level Omega‐3 Eicosapentaenoic Acid (EPA) Production from Phaeodactylum tricornutum

Phaeodactylum tricornutum is a lipid‐rich marine diatom that contains a high level of omega‐3 polyunsaturated fatty acids, especially eicosapentaenoic acid (EPA). In an effort to reduce costs for large‐scale cultivation of this microalga, this study first established a New BBM medium (0.3 x strength BBM with only 3% of the initial phosphate level) to replace the traditional F/2 medium. Phaeodactylum tricornutum could grow in extremely low phosphate concentrations (25 µM), without compromising the EPA content. In the presence of sea salts, silicate addition was not necessary for high rate growth, high EPA content, or lipid accumulation in this species. Using urea as the sole nitrogen source tended to increase EPA contents per dry biomass (by 24.7%) while not affecting growth performance. The use of sea salts, rather than just sodium chloride, led to significantly improved biomass yields (20% increase) and EPA contents of total fatty acid (46–52% increase), most likely because it supplied sufficient essential elements such as magnesium. A salinity level of 35 led to significantly higher biomass yields compared with 20, but salinity had no significant influence on EPA content. EPA became the dominant fatty acid with average levels of 51.8% of total fatty acids during the exponential growth phase at 20 ppt in New BBM medium with sea salts.     

Multiple loci mapping via model-free variable selection

Despite recent flourish of proposals on variable selection, genome-wide multiple loci mapping remains to be challenging. The majority of existing variable selection methods impose a model, and often the homoscedastic linear model, prior to selection. However, the true association between the phenotypical trait and the genetic markers is rarely known a priori, and the presence of epistatic interactions makes the association more complex than a linear relation. Model-free variable selection offers a useful alternative in this context, but the fact that the number of markers p often far exceeds the number of experimental units n renders all the existing model-free solutions that require n > p inapplicable. In this article, we examine a number of model-free variable selection methods for small-n-large-p regressions in the context of genome-wide multiple loci mapping. We propose and advocate a multivariate group-wise adaptive penalization solution, which requires no model prespecification and thus works for complex trait-marker association, and handles one variable at a time so that works for n < p. Effectiveness of the new method is demonstrated through both intensive simulations and a comprehensive real data analysis across 6100 gene expression traits.     

Site‐specific fluorescein labeling of human insulin

Three fluorescein derivatives of human insulin (HI, 1 ) labeled at positions N^αA1, N^αB1 and N^εB29 respectively, were synthesized using an N‐trifluoroacetyl‐based protecting group scheme. The Tfa protecting group introduced by reaction with ethyl trifluoroacetate was found to be stable in aqueous and organic media and efficiently removed under mild basic conditions. Copyright © 2012 European Peptide Society and John Wiley & Sons, Ltd.     

Trade‐off between flight capability and reproduction in male Velarifictorus asperses crickets

1. There are numerous data that support the trade‐off between flight capability and reproduction in female wing polymorphic insects, but the relationship between wing form and fitness remains poorly investigated in males. 2. In the present study, the development of flight muscle and gonads, spermatophore size, and multiple copulation ability were investigated in both long‐winged (LW) and short‐winged (SW) males to verify this trade‐off, using a wing dimorphic cricket species Velarifictorus aspersus (Walker). 3. The LW males had better‐developed wing muscles than the SW males on the day of emergence, and both of them developed wing muscles after emergence, but the peak of weight in SW males was achieved 4 days later than that of the LW males. The accessory glands (AG) of the LW males developed significantly slower than that of the SW males. These results suggest that development and maintenance of flight muscles have a cost on the development of reproductive organs in male V. asperses. 4. The SW males produced significantly heavier spermatophores in a single copulation and mated more often than LW males. This indicates the SW males have a higher mating success than the LW males, thereby increasing their chance of siring offspring.     

A new cell line from Spodoptera exigua (Lepidoptera: Noctuidae) and its differentially expressed genes

A new cell line, designated IOZCAS‐Spex XI, was established from the pupal ovaries of Spodoptera exigua (Lepidoptera: Noctuidae) in TNM‐FH medium containing 10% foetal bovine serum. The spherical cells were predominant among the various cell types. The population‐doubling time during the logarithmic phase of growth was 81.7 h. It was confirmed that the cell line originated from S. exigua by DAF‐PCR technique. Analysis of susceptibility to baculovirus showed that the new cell line was susceptible to S. exigua nucleopolyhedrovirus (SeNPV), Autographa californica multiple NPV (AcMNPV) and slightly susceptible to S. litura NPV (SpltNPV), while not permissive to Helicoverpa armigera NPV and Hyphantria cunea NPV (HcNPV). Real‐Time PCR analysis was carried out to compare some differentially expressed genes between the cell line and the primary culture. The result showed that marked significant differences were observed in the expression of the genes of SUMO‐1 activating enzyme, BCCIP‐like protein, 10 kDa HSP, CypA, receptor for activated PKC, PDI‐like protein ERp57, ALDH, DEAD box ATP‐dependent RNA helicase‐like protein (P < 0.01), while a significant difference was obtained in the expression of GST gene between the cell line and the primary culture (P < 0.05).     

Insights into wolf presence in human‐dominated landscapes: the relative role of food availability,humans and landscape attributes

Aim Understanding which human or environmental factors interact to enable or to limit the occurrence and persistence of large carnivores in human‐dominated landscapes is an important issue for their effective conservation, especially under the current scenario of global change where most of their former habitat is being transformed by humans. Location NW Iberian Peninsula. Methods We combine data on the distribution of Iberian wolves (Canis lupus signatus) living in a human‐dominated landscape in NW Spain and variation and partitioning methods to investigate the relative importance of three groups of predictors: food availability, humans and landscape attributes – each group expected to have unequal effects on wolf reproduction and survival – and their interactions on the occurrence of this species. Results We found that the group of predictors related with landscape attributes (altitude, roughness and refuge) strongly determined wolf occurrence, followed by humans and food availability. Variance partitioning analysis revealed that the three most important components determining wolf occurrence were related with landscape attributes: (1) the joint effects of the three predictor groups, (2) the joint effect of humans and landscape attributes and (3) the pure effect of landscape attributes. Altitude had the main independent contribution to explain the probability of wolf occurrence. Main conclusions In human‐dominated landscapes, the occurrence of wolves is the result of a complex interaction among several environmental and human factors. Our results suggest that the characteristics of the landscape (spatial context) – factors associated with the security of wolves facilitating that animals go unnoticed by humans, wolf movements, dispersal events and short‐time colonization – become more important in human‐dominated landscapes and may have played a key role in the occurrence and persistence of this species throughout decades modulating the relationship between humans and wolf distribution.