Les plus anciennes industries paléolithiques en Russie

Early Paleolithic sites (Oldowan and Acheulian) in the European part of Russia are concentrated in the southern part of the Russian plain, in the piedmont of the Caucasus and in the North Caucasus, south from 50 N latitude. The Taman Paleolithic complex (sites of Bogatyri/Sinyaya Balka, Rodniki 1 and 2, Kermek; and localities of Tsymbal, Lisy and Peresyp), Akushin Paleolithic complex in Central Dagestan (sites of Aynikab 1, Mukhkay 1 and 2) and complex of sites in Maritime Dagestan (sites of Rubas 1, Darvagchay 1, Darvagchay-Zaliv 1 and 4) are discovered and studied. The initial human settlement of southern Russia began about 2 Ma and went through the Caucasian isthmus along the western shore of the Caspian Sea. The most ancient Homo of the first wave of settlement from the African ancestral homeland was able to reach the Caucasus and the southern part of the Russian plain by 2 Ma, as confirmed by the Liventsovka locality in the city of Rostov-on-Don. The Acheulian is represented by stratified sites of the Early Acheulian on the territory of Dagestan. At present, it can be argued that the territory of southern Russia was part of the area of initial human settlement from Africa. It is more difficult to estimate the time and ways of the initial human settlement of Northern Asia. The few sites attributed to the Lower Paleolithic are, for the most part, geologically unconnected or are questioned as to the authenticity of the artifacts. The only clearly stratified Middle Pleistocene site, Karama in the Altai, delivered a pebble tool industry. In addition, the finds of bifaces in Tuva, near the Mongolian border mark the northern limit of the distribution of the Acheulian in Asia.     

Le parasitisme: le plus vieux métier du monde ?

Life appeared on earth 3.5 milliards years ago. Primitive cells were formed by incorporating endosymbiotic forms of bacteria. Traces of parasitism were clearly identified at each step of the Evolution and in particular during the oldest antiquity. The host-parasite coexistence has induced the emergence of remarkable genetic and behavioural modifications of which we give some examples.     

Existe-il, dans la population générale masculine un risque plus fort de développer des délétions du chromosome Y qui entraîneraient une infertilité?

The role of the Y-chromosome in spermatogenesis remains one of the hottest topics in andrology. Three non overlapping recurrently deleted regions on Yq (AZFa, AZFb, AZFc) have been defined, each of them containing several genes that are candidates for male infertility. The causes and mechanisms leading to microdeletion formation on the Y are largely unknown. Theoretically, it could be possible that some groups of Y-chromosomes (haplogroups) currently distributed in the population could confer a selective advantage/disadvantage towards deletion formation. A precedent in the field is the recent identification of a Y-chromosome haplotype that confers a selective advantage against a translocation of Yp leading to another form of male infertility, the Y+XX-male phenotype. In order to test if selection is acting on Y-chromosome haplotype distribution, we have defined and compared Y-chromosome haplotypes in a group of around 60 individuals with Y microdeletions from North-Western Europe using 10 biallelic Y-markers (SRY-2627, SRY-1532, SRY-8299, 92R7, Tat, YAP, sY81, LLY22g, M9, DYS257). The defined heplotypes were compared to a control normospermic population of the same ethnic/geographic origin (in the framework of the European Biodiversity Project). We evaluatte the relationship between different Y-chromosome backgrounds and microdeletions, and to which extent selection on this chromosome could have influenced fifness of certain individuals/populations. We also discuss the selective forces that are acting on this chromosome and speculate on the mechanisms underlying deletion formation.     

Le plus vieil établissement de métallurgistes de France (IIIe millénaire av. J.-C.) : Péret (Hérault)

The settlement of Chalcolithic metalworkers of La Capitelle du Broum is a truly outstanding site. The first AMS ¹⁴C dating (3rd millennium BC) reveals it as the oldest site in the mining and metallurgy district of Cabrières. It is of the same age as the oldest metallurgy site discovered in continental France (Roquemengarde). It includes, near the prehistoric copper mines already discovered, double-facing dry-stone walls of the Fontbouisse type and a variety of metallurgy structures. Metalworking tools, including one of the very rare ingot crucibles known from this period in Western Europe, are found alongside ceramics typical of the Late Neolithic (Broum type?). To cite this article: P. Ambert et al., C. R. Palevol 1 (2002) 67–74.     

Computational biology: plus c'est la même chose,plus ça change

A report on the joint 19th Annual International Conference on Intelligent Systems for Molecular Biology (ISMB)/10th Annual European Conference on Computational Biology (ECCB) meetings and the 7th International Society for Computational Biology Student Council Symposium, Vienna, Austria, 15-19 July 2011.     

Génétique moléculaire des dysgénésies testiculaires

The first step of male differentiation is the testis determination which is genetically controled. The key role of SRY gene is now established. However, a number of clinical and genetic data favoured the role of other genes taking place upstream or downstream SRY. Most of 46, XX males possess a translocated SRY gene and thus develop testis, but SRY gene is not found in 10% of such patients. Likewise, the molecular study of 46, XY females participated in the identification of SRY as testis determining factor, but 80% of XY gonadal dysgenesis are not explained by an abnormality of SRY gene. Several clinical situations permitted to suspect the role of autosomal (chromosome 1, 9, 10 17 …) and X chromosome loci in the pathology of sex determination. Some recent works concern, in particular, the testis determining factor of the X chromosome (TDF-X) that could act as a repressor of the testis differentiation. In conclusion, molecular mechanisms of sexual determination appear to be much complex, involving probably several genes in a pathway that remain to be elucidated.     

Cancer et Hérédité

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Rhizopodes Thécamoebiens du Vénézuéla

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Chromosomes et hétérochromosomes de ténébrionidés

Sans résumé Avec 81 figures dans le texte     

Systématique moléculaire des Mélitées

The holarctic subfamily Melitaeinae of Nymphalid butterflies (old genus Melitaea Hbn.) has been split into various genera by morphological systematics, but this division has been debated. This work presents the results of a preliminary survey of European taxa using two types of molecular criteria: analysis of enzyme variation by electrophoresis (19 loci) and sequencing of a mtDNA fragment (ND1 gene). The information provided by both kinds of markers are largely congruent. The division of the subfamily into two monophyletic lines corresponding to the genera Euphyryas s. 1. and Melitaea s. l. is validated. The subsequent division of the former genus into two units, Eurodryas and Hypodryas is also confirmed by molecular criteria. Inside rhe old genus Melitaea, a monophyletic assemblage, corresponding to the ‘Mellicta group’ is disclosed, but the phylogeny of the other species of the group is confused. Uniting them in a ‘Didymaeformia group’ or in a genus Melitaea s. str. risks rhe generation of a paraphyletic assemblage. It remains to be determined whether or not these results are due to insufficient resolution, or whether they reflecr a real evolutionary pattern