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Transdifferentiation of macrophages into fibroblasts as a result of Schistosoma mansoni infection.
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The possibility of transdifferentiation of macrophages into fibroblasts which could be at the origin of fibrotic tissue in schistosome-infected mice was studied using immunocytochemical techniques. Macrophage cell samples extracted from the peritoneal cavity of schistosome-infected mice were fractionated on a Percoll gradient. The cultures were purified by treatment with a trypsin solution to eliminate any fibroblasts possibly collected along with the macrophages. Immunocytochemical methods were then used to characterize the cells at differentpoints in time. The fibroblastic property of the morphologically transformed cells was confirmed by their positive labeling with the anti-procollagen antibody. However, these cells still possessed the mac-1 and mac-2 antigens which characterize the monomacrophage line.
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A study of peritoneal cells from healthy and Schistosoma mansoni-infected mice with special reference to myofibroblasts arising in culture.
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Adherent, trypsin-resistant, peritoneal cells from mice with chronic schistosomiasis mansoni, and from control mice, were cultivated in vitro up to 20 days. Fibroblasts regularly appeared, about 6 days after seeding, in cultures ofthe manyfold more numerous cells from infected mice, concomitantly with a dramatic increase, detected by autoradiography, in the percentage of DNA-replicating cells of the monocyte-macrophage lineage. Peritoneal cells from healthy and from infected mice were fractionated on discontinuous Percoll gradients. Eight cell subsets were harvested in both cases, quantitated, and studied by electron microscopy. Two fractions (2 and 3: 1.041 < densities < 1.060 g/ml) from infected mice were greatly enriched in monoblasts and promonocytes. The cells of the different subsets were seeded separately, trypsin-treated and cultivated in vitro. Cultures of cell fractions 2 and 3 from infected mice contained the majority of the DNA-synthesizing cells and gave regularly rise to fibroblasts. Cultures of the different fractions were used for sequential morphological observations (2-11 days) at the electron microscope level. Early cultures were also used for the ultrastructural detection of the Mac-1 (CD 18/CD11b) surface antigen by gold immunocytochemistry. A few fibroblasts were rarely observed in cultures of fractions 2 and 3 from control mice, while cells with ultrastructural features of myofibroblasts were regularly observed in cultures of the same fractions harvested from mice with chronic schistosomiasis. Fractions 2and 3 from infected mice contained a large number of Mac-1 positive monoblasts. The correlations between the presence of monoblasts, DNA replication in cells ofthe monocyte-macrophage lineage and the appearance of myofibroblasts in culturesof the same fractions derived from infected mice are discussed.
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No RBINS Staff publications
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Microfossils in calculus demonstrate consumption of plants and cooked foods in Neanderthal diets (Shanidar III, Iraq; Spy I and II, Belgium).
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The nature and causes of the disappearance of Neanderthals and their apparent replacement by modern humans are subjects of considerable debate. Many researchers have proposed biologically or technologically mediated dietary differences between the two groups as one of the fundamental causes of Neanderthal disappearance. Some scenarios have focused on the apparent lack of plant foods in Neanderthal diets. Here we report direct evidence for Neanderthalconsumption of a variety of plant foods, in the form of phytoliths and starch grains recovered from dental calculus of Neanderthal skeletons from Shanidar Cave, Iraq, and Spy Cave, Belgium. Some of the plants are typical of recent modern human diets, including date palms (Phoenix spp.), legumes, and grass seeds (Triticeae), whereas others are known to be edible but are not heavily used today. Many of the grass seed starches showed damage that is a distinctive marker of cooking. Our results indicate that in both warm eastern Mediterranean and cold northwestern European climates, and across their latitudinal range, Neanderthalsmade use of the diverse plant foods available in their local environment and transformed them into more easily digestible foodstuffs in part through cooking them, suggesting an overall sophistication in Neanderthal dietary regimes.
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RBINS collections by external author(s)
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Frontal sinuses and human evolution
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The frontal sinuses are cavities inside the frontal bone located at the junction between the face and the cranial vault and close to the brain. Despite a long history of study, understanding of their origin and variation through evolution is limited. This work compares most hominin species’ holotypes and other key individuals with extant hominids. It provides a unique and valuable perspective of the variation in sinuses position, shape, and dimensions based on a simple and reproducible methodology. We also observed a covariation between the size and shape of the sinuses and the underlying frontal lobes in hominin species from at least the appearance of Homo erectus. Our results additionally undermine hypotheses stating that hominin frontal sinuses were directly affected by biomechanical constraints resulting from either chewing or adaptation to climate. Last, we demonstrate their substantial potential for discussions of the evolutionary relationships between hominin species. Variation in frontal sinus shape and dimensions has high potential for phylogenetic discussion when studying human evolution.
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RBINS Staff Publications 2022
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Using next-generation sequencing to improve DNA barcoding: lessons from a small-scale study of wild bee species (Hymenoptera, Halictidae)
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RBINS Staff Publications 2018
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New material of the small raoellid artiodactyl Metkatius kashmiriensis Kumar and Sahni, 1985 (Mammalia) from the middle Eocene of the Kalakot area, Rajouri District, Jammu and Kashmir, India
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New material of the small raoellid artiodactyl Metkatius kashmiriensis is reported from the middle Eocene of the Upper Subathu Formation in the Kalakot area, Jammu and Kashmir, northwest Himalaya, India. The fossil material consists of numerous mandibular and maxillary fragments and isolated teeth, mainly belonging to juvenile specimens. It documents the poorly known dental morphology of M. kashmiriensis and provides an overview of its intraspecific variation, allowing to redefine its diagnosis. M. kashmiriensis is characterized by a particularly small size compared with other raoellid species, and by bunodont molars with moderately marked transverse lophs. The M/1–2 are much longer than wide and display characters similar to those of Rajouria gunnelli, such as the presence of a small paraconid and a mesial mesiostylid. The P/4 bears distally a small hypoconid, which appears to be unique in Raoellidae. The description of the new material also allows to document the poorly known morphology of the deciduous teeth of raoellids. The DP2/ is reported for the first time, and the DP/4 of M. kashmiriensis shows a morphology different from that of Indohyus, with the absence of mesial basin anterior to the paraconid and the primoconid. Contrary to what has recently been proposed, these results confirm that M. kashmiriensis is a valid species and not a synonym of Indohyus indirae, and highlight the great morphological diversity present within the Raoellidae during the middle Eocene in the Indian subcontinent.
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RBINS Staff Publications 2024 OA
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A first glimpse into the biogeographic affinities of the shallow benthic communities from the sub-Antarctic Crozet archipelago
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Sub-Antarctic islands are expected to show a high degree of endemicity due to their remoteness. However, biogeographic affinities in the sub-Antarctic remain poorly understood, especially in the marine realm. Sub-Antarctic islands being at the crossroads between Antarctic and cold temperate regions, biodiversity characterization and biogeographic analyses are a priority for monitoring and rapidly assessing variations associated with environmental changes. One underexplored sub-Antarctic area is Crozet, a protected archipelago located halfway between Antarctica and South Africa. In this study, we investigated the shallow-water Crozet macrofaunal diversity, distribution patterns and biogeographic affinities based on the examination of fieldwork specimens via a thorough morphological identification and a genetic characterisation. The resulting dataset provides an important baseline for further studies and conservation strategies, compiling the first genetic and taxonomic database for the Crozet archipelago. In total, 100 morphotypes were found, belonging to nine different phyla, among whicharthropods(32), molluscs (18)and echinoderms (17) were the richest. Forty-seven morphotypes were identified to the species level, among which 20 were reported in Crozet for the first time. This confirms that Crozet is a poorly known region, even compared to other sub-Antarctic areas. A large proportion of species (62%) had circum Southern Ocean or circum sub Antarctic distributions. These species were mostly shared with Kerguelen (72%), the Magellan Province (64%), and Prince Edward Islands (64%), confirming the patterns found in macroalgae and specific macrofaunal groups. However, this large-distribution statement needs to be counterbalanced by the detection (genetic data) of more restricted distributions than expected in four study cases (the tanaid Apseudes spectabilis, the nudibranch Doris kerguelenensis, the polychaete Neanthes kerguelensis and the chiton Hemiarthrum setulosum). Considering that most morphotypes had no genetic data available from other regions, the proportion of morphotypes with restricted distribution is likely to increase alongside future investigations. In addition, we also found a few cases of unrecognized diversity that might lead to the descriptions of new species, some likely to be endemic to Crozet (e.g., within the polychaete genus Harmothoe and the bryozoan genus Antarctothoa). Altogether, this stresses the need to maintain conservation efforts in Crozet and pursue integrative investigations in order to highlight and protect its unusual diversity
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RBINS Staff Publications 2024
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Mystacodon selenensis, the earliest known toothed mysticete (Cetacea, Mammalia) from the late Eocene of Peru: anatomy, phylogeny, and feeding adaptations
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RBINS Staff Publications 2019
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Black adzes in the Early Neolithic of Belgium. Contribution of the Raman microspectrometry and petrography in the characterization and sourcing
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Ancient Neolithic (Linear Pottery Culture) adzes originate from settlements and workshops accompany the neolithization of Belgium. They are made from a wide range of extraregional lithic raw materials such as metamorphic green rocks (amphibolite) and black volcanic rocks (‘basalt’) beside more local or regional raw material as flints, light-coloured (sedimentary and lightly metamorphic) quartzites and fine-grained black rocks. Another material source included black lydites (Cambrian nodular phtanite of Céroux-Mousty and Lower Namurian banded phtanites) and dark grey Lower Namurian silicified sandstones called ‘Micaceous sandstones of Horion-Hozémont’. The discovery of the workshop of Noir Fontaine near the city of Liège in the 1970s and 1980s provides exceptional assemblage available for updating analytical studies. This research focuses on the multi-scale characterization, the discrimination and sourcing of the different types of fine-grained black materials composing Ancient Neolithic adzes found in Belgium. Their black colour results from finely dispersed organic matter, but the absence of palynomorphs does not allow a biostratigraphic ascription. Additional petrographical analyses (Optical Petrography - OP, Scanning Electronic Microscopy - SEM), X-ray diffraction (XRD), chemical analyses (Energy Dispersive Spectroscopy - EDS) and measuring the degree of graphitization of the organic matter through Raman microspectrometry have been decisive in identifying the geological and geographical provenances by comparing the acquired results with geological reference samples collected in the field or through reference collections. The distribution of the different black coloured rocks shows that Cambrian lydites are coming from a very restricted area and were preferred to other more local rock sources.
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RBINS Staff Publications 2021
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Middle Neolithic fluorites in Northern France and Belgium: Characterization, sourcing and methodological limitations.
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Abstract Ornaments and fragments of fluorite have been found at sixteen Neolithic sites in Belgium and Northern France, mainly Middle Neolithic sites associated with the Michelsberg culture and the Spiere and Chassean groups. These sites are located in a large geographical area representing different types of sites and various geological backgrounds. One of the aims of this study is to identify where this mineral could have been quarried in the Neolithic and compare the possible source(s) with those used during the Palaeolithic. A survey of some Neolithic fluorite occurrences in Belgium and Northern France was conducted and the origins of this mineral determined/investigated by means of geochemical Rare Earth Element (REE) and Sr-isotopic analysis. We also explore the limitations of isotopic 87Sr/86Sr and REE ratios for analysis of fluorite. Results show that Neolithic fluorite originates from the Dinantian limestones/dolostones of the Ardennes Allochthon, in contrast to the use of silicified Givetian limestones of the Calestian Band near Givet (France) during the Magdalenian. Keywords: Fluorite ornaments, Middle Neolithic, REE, Sr isotopes, Northern France, Belgium
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RBINS Staff Publications 2021
