Diversité des cheptels et diversification des morphotypes bovins dans le tiers nord-ouest des Gaules entre la fin de l’âge du Fer et la période romaine

International audienceIt is assumed that in the Roman West we see the development of taller and more robust domestic animals than during Iron Age but great uncertainties remain concerning the process that led to these transformations. This paper is a contribution to a better understanding of these modifications. From a large bone assemblage (about 12,000 pieces, that is to say more than 50,000 measurements) taken from 85 towns in Belgium and in the third north-western France, an osteometric research has been conducted on one species (essentially based on the Log Size Index method): cattle. Results highlighted new features in the characteristics of Celtic and Roman herds. The first one shows the heterogeneity of the indigenous livestock with strong variations according to geographical areas. Some civitates have herds of high stature animals while others raised smaller ones. The other information lies in the diversity of the dynamics of appearance and diffusion of large bovids. Each territory acted differently to these transformations, according to its degree of assimilation, resources at its disposal, soil quality or agrarian culture, showing distinct evolutions in the size of the animals as in their morphology.S'il est admis que, dans les provinces occidentales de l'Empire, la période romaine est le théâtre du développement d'animaux domestiques plus grands et plus robustes qu'à l'époque gauloise, de fortes incertitudes persistent quant aux processus ayant amené les changements observés. Cet article se propose donc de contribuer à mieux les comprendre. À partir d'un important corpus d'os (près de 12 000 pièces, soit plus de 50 000 mesures), tiré de 85 communes de Belgique et du tiers nord-ouest de la France, un travail ostéométrique (basé essentiellement sur la méthode du Log Size Index) a été mené sur une espèce : le boeuf. Les résultats mettent en lumière des aspects inédits des caractéristiques des troupeaux gaulois et romains. Le premier enseignement de cette étude est la mise en évidence de l'hétérogénéité du cheptel indigène qui présente de fortes variations selon les zones géographiques. Certaines cités présentent des troupeaux constitués d'animaux de hautes statures, tandis que d'autres utilisent des bêtes plus petites. L'autre information réside dans la diversité des dynamiques d'apparition et de diffusion des grands bovins. Chaque territoire, selon son degré d'assimilation des nouvelles techniques, selon les ressources disponibles, la qualité de son sol, ou sa culture agraire, a réagi de manière différente à ces transformations, révélant des évolutions distinctes tant du point de vue de la taille des bêtes que de leur morphologie

Le castor Castor fiber Linnaeus, 1758 en France. Étude archéozoologique

International audienceThis contribution draws up a first inventory of the discoveries of remains of beaver in archaeological contexts and characterizes the place as well as the role of this animal in societies, since the end of the Prehistory until the medieval period. This work establishes a first synthesis on the subject in the French metropolitan territory and rests on an analysis of the representation of the species and its anatomical parts as well as of the anthropical marks observed on bones. It also draws on a study of textual sources for the relevant periods.Cette contribution dresse un premier état des lieux des découvertes de restes de castor en contexte archéologique et caractérise la place et le rôle de cet animal dans les sociétés, depuis la fin de la Préhistoire jusqu’à la période médiévale. Ce travail constitue une première synthèse sur le sujet en France métropolitaine et repose essentiellement sur une analyse de la représentation de l’espèce et de ses parties anatomiques ainsi que des traces anthropiques observées sur les ossements. Il s’appuie également sur une étude des sources textuelles pour les périodes concernées

Super-telomeres in transformed human fibroblasts

Telomere length maintenance is critical for organisms' long-term survival and cancer cell proliferation. Telomeres are kept within species-specific length ranges by the interplay between telomerase activity and telomeric chromatin organization. In this paper, we exploited telomerase immortalized human fibroblasts (cen3tel) that gradually underwent neoplastic transformation during culture propagation to study telomere composition and length regulation during the transformation process. Just after telomerase catalytic subunit (hTERT) expression, cen3tel telomeres shortened despite the presence of telomerase activity. At a later stage and concomitantly with transformation, cells started elongating telomeres, which reached a mean length greater than 100kb in about 900 population doublings. Super-telomeres were stable and compatible with cell growth and tumorigenesis. Telomere extension was associated with increasing levels of telomerase activity that were linked to the deregulation of endogenous telomerase RNA (hTERC) and exogenous telomerase reverse transcriptase (hTERT) expression. Notably, the increase in hTERC levels paralleled the increase in telomerase activity, suggesting that this subunit plays a role in regulating enzyme activity. Telomeres ranging in length between 10 and more than 100kb were maintained in an extendible state although TRF1 and TRF2 binding increased with telomere length. Super-telomeres neither influenced subtelomeric region global methylation nor the expression of the subtelomeric gene FRG1, attesting the lack of a clear-cut relationship between telomere length, subtelomeric DNA methylation and expression in human cells. The cellular levels of the telomeric proteins hTERT, TRF1, TRF2 and Hsp90 rose with transformation and were independent of telomere length, pointing to a role of these proteins in tumorigenesis

A transcriptomic analysis of human centromeric and pericentric sequences in normal and tumor cells

Although there is now evidence that the expression of centromeric (CT) and pericentric (PCT) sequences are key players in major genomic functions, their transcriptional status in human cells is still poorly known. The main reason for this lack of data is the complexity and high level of polymorphism of these repeated sequences, which hampers straightforward analyses by available transcriptomic approaches. Here a transcriptomic macro-array dedicated to the analysis of CT and PCT expression is developed and validated in heat-shocked (HS) HeLa cells. For the first time, the expression status of CT and PCT sequences is analyzed in a series of normal and cancer human cells and tissues demonstrating that they are repressed in all normal tissues except in the testis, where PCT transcripts are found. Moreover, PCT sequences are specifically expressed in HS cells in a Heat-Shock Factor 1 (HSF1)-dependent fashion, and we show here that another independent pathway, involving DNA hypo-methylation, can also trigger their expression. Interestingly, CT and PCT were found illegitimately expressed in somatic cancer samples, whereas PCT were repressed in testis cancer, suggesting that the expression of CT and PCT sequences may represent a good indicator of epigenetic deregulations occurring in response to environmental changes or in cell transformation

dSAP18 and dHDAC1 contribute to the functional regulation of the Drosophila Fab-7 element

It was described earlier that the Drosophila GAGA factor [Trithorax-like (Trl)] interacts with dSAP18, which, in mammals, was reported to be a component of the Sin3–HDAC co-repressor complex. GAGA–dSAP18 interaction was proposed to contribute to the functional regulation of the bithorax complex (BX-C). Here, we show that mutant alleles of Trl, dsap18 and drpd3/hdac1 enhance A6-to-A5 transformation indicating a contribution to the regulation of Abd-B expression at A6. In A6, expression of Abd-B is driven by the iab-6 enhancer, which is insulated from iab-7 by the Fab-7 element. Here, we report that GAGA, dSAP18 and dRPD3/HDAC1 co-localize to ectopic Fab-7 sites in polytene chromosomes and that mutant Trl, dsap18 and drpd3/hdac1 alleles affect Fab-7-dependent silencing. Consistent with these findings, chromatin immunoprecipitation analysis shows that, in Drosophila embryos, the endogenous Fab-7 element is hypoacetylated at histones H3 and H4. These results indicate a contribution of GAGA, dSAP18 and dRPD3/HDAC1 to the regulation of Fab-7 function

The orphan receptor ERRα interferes with steroid signaling

The estrogen receptor-related receptor α (ERRα) is an orphan member of the nuclear receptor superfamily that has been shown to interfere with the estrogen-signaling pathway. In this report, we demonstrate that ERRα also cross-talks with signaling driven by other steroid hormones. Treatment of human prostatic cells with a specific ERRα inverse agonist reduces the expression of several androgen-responsive genes, in a manner that does not involve perturbation of androgen receptor expression or activity. Furthermore, ERRα activates the expression of androgen response elements (ARE)-containing promoters, such as that of the prostate cancer marker PSA, in an ARE-dependent manner. In addition, promoters containing a steroid response element can be activated by all members of the ERR orphan receptor subfamily, and this, even in the presence of antisteroid compounds

Evolutionary Plasticity of Polycomb/Trithorax Response Elements in Drosophila Species

cis-Regulatory DNA elements contain multiple binding sites for activators and repressors of transcription. Among these elements are enhancers, which establish gene expression states, and Polycomb/Trithorax response elements (PREs), which take over from enhancers and maintain transcription states of several hundred developmentally important genes. PREs are essential to the correct identities of both stem cells and differentiated cells. Evolutionary differences in cis-regulatory elements are a rich source of phenotypic diversity, and functional binding sites within regulatory elements turn over rapidly in evolution. However, more radical evolutionary changes that go beyond motif turnover have been difficult to assess. We used a combination of genome-wide bioinformatic prediction and experimental validation at specific loci, to evaluate PRE evolution across four Drosophila species. Our results show that PRE evolution is extraordinarily dynamic. First, we show that the numbers of PREs differ dramatically between species. Second, we demonstrate that functional binding sites within PREs at conserved positions turn over rapidly in evolution, as has been observed for enhancer elements. Finally, although it is theoretically possible that new elements can arise out of nonfunctional sequence, evidence that they do so is lacking. We show here that functional PREs are found at nonorthologous sites in conserved gene loci. By demonstrating that PRE evolution is not limited to the adaptation of preexisting elements, these findings document a novel dimension of cis-regulatory evolution

Towards the identification of a new taphonomic agent: An analysis of bone accumulations obtained from modern Egyptian vulture (Neophron percnopterus) nests

This paper presents the results of a study of bones recovered in various current Egyptian vulture (Neophron percnopterus) nests in a Mediterranean region of the Iberian Peninsula. The Egyptian vulture, a diurnal, scavenging, rupicolous bird of prey, is one of four vulture species that currently inhabit the Iberian Peninsula. An analysis of the remains found in the nests confirms that it has a heterogeneous diet that includes remains from human activities (butchery and food production) and the carcasses of dead animals, although it is possible that they also prey on small-sized taxa. The taphonomic study determines these birds" capability of transporting, accumulating and altering bone remains. Some of the elements show marks caused by beak and/or claw impacts brought about primarily during feeding, which have characteristic typologies. Despite the fact that this is not a bone-eating vulture, it can also be seen that some bones are swallowed. The characteristics of the bone set studied here are important for establishing the origin of bone accumulations on archaeological sites

A global view of the nonprotein-coding transcriptome in Plasmodium falciparum

Nonprotein-coding RNAs (npcRNAs) represent an important class of regulatory molecules that act in many cellular pathways. Here, we describe the experimental identification and validation of the small npcRNA transcriptome of the human malaria parasite Plasmodium falciparum. We identified 630 novel npcRNA candidates. Based on sequence and structural motifs, 43 of them belong to the C/D and H/ACA-box subclasses of small nucleolar RNAs (snoRNAs) and small Cajal body-specific RNAs (scaRNAs). We further observed the exonization of a functional H/ACA snoRNA gene, which might contribute to the regulation of ribosomal protein L7a gene expression. Some of the small npcRNA candidates are from telomeric and subtelomeric repetitive regions, suggesting their potential involvement in maintaining telomeric integrity and subtelomeric gene silencing. We also detected 328 cis-encoded antisense npcRNAs (asRNAs) complementary to P. falciparum protein-coding genes of a wide range of biochemical pathways, including determinants of virulence and pathology. All cis-encoded asRNA genes tested exhibit lifecycle-specific expression profiles. For all but one of the respective sense–antisense pairs, we deduced concordant patterns of expression. Our findings have important implications for a better understanding of gene regulatory mechanisms in P. falciparum, revealing an extended and sophisticated npcRNA network that may control the expression of housekeeping genes and virulence factors