Refined Candidate Region for F4ab/ac Enterotoxigenic Escherichia coli Susceptibility Situated Proximal to MUC13 in Pigs

F4 enterotoxigenic Escherichia coli (F4 ETEC) are an important cause of diarrhea in neonatal and newly-weaned pigs. Based on the predicted differential O-glycosylation patterns of the 2 MUC13 variants (MUC13A and MUC13B) in F4ac ETEC susceptible and F4ac ETEC resistant pigs, the MUC13 gene was recently proposed as the causal gene for F4ac ETEC susceptibility. Because the absence of MUC13 on Western blot from brush border membrane vesicles of F4ab/acR⁺ pigs and the absence of F4ac attachment to immunoprecipitated MUC13 could not support this hypothesis, a new GWAS study was performed using 52 non-adhesive and 68 strong adhesive pigs for F4ab/ac ETEC originating from 5 Belgian farms. A refined candidate region (chr13: 144,810,100–144,993,222) for F4ab/ac ETEC susceptibility was identified with MUC13 adjacent to the distal part of the region. This candidate region lacks annotated genes and contains a sequence gap based on the sequence of the porcine GenomeBuild 10.2. We hypothesize that a porcine orphan gene or trans-acting element present in the identified candidate region has an effect on the glycosylation of F4 binding proteins and therefore determines the F4ab/ac ETEC susceptibility in pigs.     

Locomotor activity rhythms in two sympatric parasitoid insects: Eupelmus orientalis and Eupelmus vuilleti (Hyménoptera, Eupelmidae)

With an automatic image analysis device, we studied the temporal distribution of the locomotor activity of E. orientalis and E. vuilleti during 24 h, and over several days to know whether the activity rhythms of these two Eupelmidae play a role in their competitive interactions. The analysis of locomotor activity rhythms of E. orientalis and E. vuilleti shows that the locomotor activity of both species presents daily cyclic variations. These two Eupelmidae have similar activity rhythms. Displacements of these parasitoids essentially take place during the photophase. But the activity of E. vuilleti is earlier, because the individuals of this species start their activity on average 4 to 5 h earlier than those of E. orientalis. E. vuilleti begins its displacements several hours before the onset of lighting, whereas E. orientalis is active only in the presence of the light. This shift of starting activity is thus a factor allowing these concurrent species to minimize their interactions during the cohabitation period in traditional granaries after the harvests of cowpea.     

La séquence de Moulin Quignon est-elle une séquence archéologique ?

The sequence of the Moulin Quignon quarry yielded archaeological findings (faunal remains, artefacts) and some of them are well located in the stratigraphy thanks to Jacques Boucher de Perthes and colleagues. These remains are often used to attest the early age of the site and the human remains. Some bifaces have been found in close relationship to the human remains and, in particular, the mandible found in 1863. Thanks to the handwritten label put on the pieces and their deposit at the National Museum of Natural History (Paris), it is possible to study them again in relation with the sequence. The study concerns the rare faunal remains and the bifaces given, among others, by Boucher de Perthes to the Museum. The paleontological and technological analyses allow us replacing the lithic material among the north-western European data. The material is presented according to the historical context of his discovery.     

Blue-throated macaws (Ara glaucogularis) succeed in a cooperative task without coordinating their actions

Social complexity may select for socio-cognitive abilities. The “loose string” task has become a comparative benchmark paradigm for investigating cooperative problem-solving abilities in many species, thus enhancing our understanding of their evolution. It requires two individuals working together to solve a problem, specifically by pulling the two ends of a string simultaneously to move a reward towards them. A dyad's performance therefore depends on the individuals’ ability to coordinate their pulling action. Many species, including corvids and parrots, have been tested in this paradigm, but most appear insensitive to the exact cooperative nature of the task. We tested another parrot species, blue-throated macaws, to further our understanding of social cognition in psittacids. Five birds were tested with different partners in a dyadic setting. The study included two control conditions examining the cognitive mechanism underlying their seemingly cooperative behaviour. All birds were able to simultaneously pull the strings, but their performance did not drop when they were denied mutual visual access, and they failed to obtain food when they needed to wait for their partner. Moreover, the parrots decreased their latency to pull with increasing experience. These findings suggest that the birds may have applied an associatively learnt rule, or relied on acoustic cues, rather than coordinating their actions with the partner. This may not necessarily prove a lack of understanding the partner's role, given that their failure to wait in the delay control test might be explained by their poor inhibitory control abilities. Relationship quality (i.e. affiliation and food tolerance) did not influence dyadic success. Future studies are needed in order to disentangle macaws’ potentially limited cooperative abilities from their lack of inhibitory control.     

A deep-sea bacterium related to coastal marine pathogens

Evolution of virulence traits from adaptation to environmental niches other than the host is probably a common feature of marine microbial pathogens, whose knowledge might be crucial to understand their emergence and pathogenetic potential. Here, we report genome sequence analysis of a novel marine bacterial species, Vibrio bathopelagicus sp. nov., isolated from warm bathypelagic waters (3309 m depth) of the Mediterranean Sea. Interestingly, V. bathopelagicus sp. nov. is closely related to coastal Vibrio strains pathogenic to marine bivalves. V. bathopelagicus sp. nov. genome encodes genes involved in environmental adaptation to the deep-sea but also in virulence, such as the R5.7 element, MARTX toxin cluster, Type VI secretion system and zinc-metalloprotease, previously associated with Vibrio infections in farmed oysters. The results of functional in vitro assays on immunocytes (haemocytes) of the Mediterranean mussel Mytilus galloprovincialis and the Pacific oyster Crassostrea gigas, and of the early larval development assay in Mytilus support strong toxicity of V. bathopelagicus sp. nov. towards bivalves. V. bathopelagicus sp. nov., isolated from a remote Mediterranean bathypelagic site, is an example of a planktonic marine bacterium with genotypic and phenotypic traits associated with animal pathogenicity, which might have played an evolutionary role in the origin of coastal marine pathogens.