Complex patterns of grooming and sexual activity in Barbary macaques (Macaca sylvanus)

Grooming in primates is often considered a “currency” that can be exchanged for other “services” or “commodities” such as reciprocal grooming, coalitionary support, infant handling, tolerance around food sources, active food sharing, or mating opportunities. Previous studies on primate grooming‐for‐sex exchange viewed the males as the demanding class, with the females as suppliers of mating opportunities. In this study, we examine the broader context of grooming‐for‐mating exchange in Barbary macaques in Gibraltar. Our data show that Barbary macaque males groom females with whom they are mating more frequently and for longer periods than other females, and the relationship between grooming and mating remains significant in both sexual and nonsexual contexts. In addition, females groomed males with whom they were mating more frequently and for longer periods than other males. In both sexes, grooming was observed to be far more frequent and to occur for longer durations in sexual compared to nonsexual contexts. We did not find any difference in grooming behavior between presexual and postsexual contexts. Our data suggest that there is no simple model to describe Barbary macaque grooming patterns in sexual contexts. Although our results are partly consistent with male use of grooming as payment for mating, broadly assessed grooming‐mating patterns cannot be solely explained by a male‐driven grooming‐for‐mating exchange.     

Conserved DNA Motifs,Including the CENP-B Box-like,Are Possible Promoters of Satellite DNA Array Rearrangements in Nematodes

Tandemly arrayed non-coding sequences or satellite DNAs (satDNAs) are rapidly evolving segments of eukaryotic genomes, including the centromere, and may raise a genetic barrier that leads to speciation. However, determinants and mechanisms of satDNA sequence dynamics are only partially understood. Sequence analyses of a library of five satDNAs common to the root-knot nematodes Meloidogyne chitwoodi and M. fallax together with a satDNA, which is specific for M. chitwoodi only revealed low sequence identity (32–64%) among them. However, despite sequence differences, two conserved motifs were recovered. One of them turned out to be highly similar to the CENP-B box of human alpha satDNA, identical in 10–12 out of 17 nucleotides. In addition, organization of nematode satDNAs was comparable to that found in alpha satDNA of human and primates, characterized by monomers concurrently arranged in simple and higher-order repeat (HOR) arrays. In contrast to alpha satDNA, phylogenetic clustering of nematode satDNA monomers extracted either from simple or from HOR array indicated frequent shuffling between these two organizational forms. Comparison of homogeneous simple arrays and complex HORs composed of different satDNAs, enabled, for the first time, the identification of conserved motifs as obligatory components of monomer junctions. This observation highlights the role of short motifs in rearrangements, even among highly divergent sequences. Two mechanisms are proposed to be involved in this process, i.e., putative transposition-related cut-and-paste insertions and/or illegitimate recombination. Possibility for involvement of the nematode CENP-B box-like sequence in the transposition-related mechanism and together with previously established similarity of the human CENP-B protein and pogo-like transposases implicate a novel role of the CENP-B box and related sequence motifs in addition to the known function in centromere protein binding.     

Neutrophils Contribute to the Protection Conferred by ArtinM against Intracellular Pathogens: A Study on Leishmania major

ArtinM, a D-mannose binding lectin from Artocarpus heterophyllus, has immunomodulatory activities through its interaction with N-glycans of immune cells, culminating with the establishment of T helper type 1 (Th1) immunity. This interaction protects mice against intracellular pathogens, including Leishmania major and Leishmania amazonensis. ArtinM induces neutrophils activation, which is known to account for both resistance to pathogens and host tissue injury. Although exacerbated inflammation was not observed in ArtinM-treated animals, assessment of neutrophil responses to ArtinM is required to envisage its possible application to design a novel immunomodulatory agent based on carbohydrate recognition. Herein, we focus on the mechanisms through which neutrophils contribute to ArtinM-induced protection against Leishmania, without exacerbating inflammation. For this purpose, human neutrophils treated with ArtinM and infected with Leishmania major were analyzed together with untreated and uninfected controls, based on their ability to eliminate the parasite, release cytokines, degranulate, produce reactive oxygen species (ROS), form neutrophil extracellular traps (NETs) and change life span. We demonstrate that ArtinM-stimulated neutrophils enhanced L. major clearance and at least duplicated tumor necrosis factor (TNF) and interleukin-1beta (IL-1β) release; otherwise, transforming growth factor-beta (TGF-β) production was reduced by half. Furthermore, ROS production and cell degranulation were augmented. The life span of ArtinM-stimulated neutrophils decreased and they did not form NETs when infected with L. major. We postulate that the enhanced leishmanicidal ability of ArtinM-stimulated neutrophils is due to augmented release of inflammatory cytokines, ROS production, and cell degranulation, whereas host tissue integrity is favored by their shortened life span and the absence of NET formation. Our results reinforce the idea that ArtinM may be considered an appropriate molecular template for the construction of an efficient anti-infective agent.     

Liver fatty acid-binding protein in two cases of human lipid storage

Summary FABPs in the various tissues play an important role in the intracellular fatty acid transport and metabolism. Reye's syndrome (RS) and multisystemic lipid storage (MLS) are human disorders characterized by a disturbance of lipid metabolism of unknown etiology. We investigated for the first time L-FABP in these two conditions. Affinity purified antibodies against chicken L-FABP were raised in rabbits, and found to cross-react specifically with partially purified human L-FABP. L-FABP content in liver samples of two patients with RS and MLS was investigated by immuno-histochemistry, SDS-PAGE and ELISA. L-FABP immuno-histochemistry showed increased reactivity in the liver of RS patient and normal reactivity in MLS liver. L-FABP increase in RS liver was confirmed by densitometry of SDS-PAGE and ELISA method. By these two methods the increase amounted to 180% and 199% (p < 0.02), respectively, as compared to controls. A possible role of L-FABP in the pathogenesis of RS is discussed.     

Optimization of speed and accuracy of decoding in translation

The speed and accuracy of protein synthesis are fundamental parameters for understanding the fitness of living cells, the quality control of translation, and the evolution of ribosomes. In this study, we analyse the speed and accuracy of the decoding step under conditions reproducing the high speed of translation in vivo. We show that error frequency is close to 10⁻³, consistent with the values measured in vivo. Selectivity is predominantly due to the differences in k_cat values for cognate and near-cognate reactions, whereas the intrinsic affinity differences are not used for tRNA discrimination. Thus, the ribosome seems to be optimized towards high speed of translation at the cost of fidelity. Competition with near- and non-cognate ternary complexes reduces the rate of GTP hydrolysis in the cognate ternary complex, but does not appreciably affect the rate-limiting tRNA accommodation step. The GTP hydrolysis step is crucial for the optimization of both the speed and accuracy, which explains the necessity for the trade-off between the two fundamental parameters of translation.     

Selection of a Borrelia burgdorferi antigenic variant by cultivation in the presence of increasing amounts of homologous immune serum

This investigation was undertaken to select antigenic variants of a Borrelia burgdorferi strain in vitro. The original strain BITS was cultivated in BSK medium supplemented with increasing concentrations of homologous hyperimmune serum raised in rabbits. After a few serial passages starting from a subinhibitory serum dilution of 1:800 in BSK up to 1:200, a variant named BITSv was obtained; it grew abundantly like the control culture in the presence of hyperimmune serum. Analysis of the antigenic pattern of the original and derived variants by Western blotting revealed that BITSv, compared to the original strain BITS, had lost the reactivity with the immune serum at the level of the oligosaccharide moiety. These experiments, designed to mimic the possible action of antibodies that arise during a Borrelia infection, suggest that lipopolysaccharides are surface located and that they play a role in the integrity of the outer membrane during the multiplication of Borrelia burgdorferi.     

Snapshot prediction of carbon productivity,carbon and protein content in a Southern Ocean diatom using FTIR spectroscopy

Diatoms, an important group of phytoplankton, bloom annually in the Southern Ocean, covering thousands of square kilometers and dominating the region''s phytoplankton communities. In their role as the major food source to marine grazers, diatoms supply carbon, nutrients and energy to the Southern Ocean food web. Prevailing environmental conditions influence diatom phenotypic traits (for example, photophysiology, macromolecular composition and morphology), which in turn affect the transfer of energy, carbon and nutrients to grazers and higher trophic levels, as well as oceanic biogeochemical cycles. The paucity of phenotypic data on Southern Ocean phytoplankton limits our understanding of the ecosystem and how it may respond to future environmental change. Here we used a novel approach to create a ‘snapshot'' of cell phenotype. Using mass spectrometry, we measured nitrogen (a proxy for protein), total carbon and carbon-13 enrichment (carbon productivity), then used this data to build spectroscopy-based predictive models. The models were used to provide phenotypic data for samples from a third sample set. Importantly, this approach enabled the first ever rate determination of carbon productivity from a single time point, circumventing the need for time-series measurements. This study showed that Chaetoceros simplex was less productive and had lower protein and carbon content during short-term periods of high salinity. Applying this new phenomics approach to natural phytoplankton samples could provide valuable insight into understanding phytoplankton productivity and function in the marine system.     

Selective Vulnerability of Spinal and Cortical Motor Neuron Subpopulations in delta7 SMA Mice

Loss of the survival motor neuron gene (SMN1) is responsible for spinal muscular atrophy (SMA), the most common inherited cause of infant mortality. Even though the SMA phenotype is traditionally considered as related to spinal motor neuron loss, it remains debated whether the specific targeting of motor neurons could represent the best therapeutic option for the disease. We here investigated, using stereological quantification methods, the spinal cord and cerebral motor cortex of ∆7 SMA mice during development, to verify extent and selectivity of motor neuron loss. We found progressive post-natal loss of spinal motor neurons, already at pre-symptomatic stages, and a higher vulnerability of motor neurons innervating proximal and axial muscles. Larger motor neurons decreased in the course of disease, either for selective loss or specific developmental impairment. We also found a selective reduction of layer V pyramidal neurons associated with layer V gliosis in the cerebral motor cortex. Our data indicate that in the ∆7 SMA model SMN loss is critical for the spinal cord, particularly for specific motor neuron pools. Neuronal loss, however, is not selective for lower motor neurons. These data further suggest that SMA pathogenesis is likely more complex than previously anticipated. The better knowledge of SMA models might be instrumental in shaping better therapeutic options for affected patients.