Uncoupling of sexual reproduction from homologous recombination in homozygous Oenothera species

Salient features of the first meiotic division are independent segregation of chromosomes and homologous recombination (HR). In non-sexually reproducing, homozygous species studied to date HR is absent. In this study, we constructed the first linkage maps of homozygous, bivalent-forming Oenothera species and provide evidence that HR was exclusively confined to the chromosome ends of all linkage groups in our population. Co-segregation of complementary DNA-based markers with the major group of AFLP markers indicates that HR has only a minor role in generating genetic diversity of this taxon despite its efficient adaptation capability. Uneven chromosome condensation during meiosis in Oenothera may account for restriction of HR. The use of plants with ancient chromosomal arm arrangement demonstrates that limitation of HR occurred before and independent from species hybridizations and reciprocal translocations of chromosome arms—a phenomenon, which is widespread in the genus. We propose that consecutive loss of HR favored the evolution of reciprocal translocations, beneficial superlinkage groups and ultimately permanent translocation heterozygosity

Complete Genome Sequence of the Aerobic CO-Oxidizing Thermophile Thermomicrobium roseum

In order to enrich the phylogenetic diversity represented in the available sequenced bacterial genomes and as part of an “Assembling the Tree of Life” project, we determined the genome sequence of Thermomicrobium roseum DSM 5159. T. roseum DSM 5159 is a red-pigmented, rod-shaped, Gram-negative extreme thermophile isolated from a hot spring that possesses both an atypical cell wall composition and an unusual cell membrane that is composed entirely of long-chain 1,2-diols. Its genome is composed of two circular DNA elements, one of 2,006,217 bp (referred to as the chromosome) and one of 919,596 bp (referred to as the megaplasmid). Strikingly, though few standard housekeeping genes are found on the megaplasmid, it does encode a complete system for chemotaxis including both chemosensory components and an entire flagellar apparatus. This is the first known example of a complete flagellar system being encoded on a plasmid and suggests a straightforward means for lateral transfer of flagellum-based motility. Phylogenomic analyses support the recent rRNA-based analyses that led to T. roseum being removed from the phylum Thermomicrobia and assigned to the phylum Chloroflexi. Because T. roseum is a deep-branching member of this phylum, analysis of its genome provides insights into the evolution of the Chloroflexi. In addition, even though this species is not photosynthetic, analysis of the genome provides some insight into the origins of photosynthesis in the Chloroflexi. Metabolic pathway reconstructions and experimental studies revealed new aspects of the biology of this species. For example, we present evidence that T. roseum oxidizes CO aerobically, making it the first thermophile known to do so. In addition, we propose that glycosylation of its carotenoids plays a crucial role in the adaptation of the cell membrane to this bacterium's thermophilic lifestyle. Analyses of published metagenomic sequences from two hot springs similar to the one from which this strain was isolated, show that close relatives of T. roseum DSM 5159 are present but have some key differences from the strain sequenced

Molecular, Cellular and Pharmaceutical Aspects of Biomaterials in Dentistry and Oral and Maxillofacial Surgery. An Internationalization of Higher Education and Research Perspective.

In dentistry and oral and maxillofacial surgery, the development of implantable biomaterials and the understanding of their molecular, cellular and pharmaceutical aspects are currently major fields of research and education, with a considerable impact on the daily clinical practice and the evolution of therapeutic strategies. In the era of globalized economy of knowledge and science, this scientific domain needs the development of global cooperation and a paradigm evolution in the organizational culture of the dental sciences and related dental industry. Despite political pressure and theoretical efforts, the internationalization of higher education and research today in dentistry and biomaterials remains in general quite superficial and mostly dependent on the efforts of a few leaders of internationalization working through their personal networks, as it was assessed through the FAST scores (Fast Assessment Screening Test) calculated in various dental schools and groups worldwide through the ISAIAS program (Intercultural Sensitivity Academic Index & Advanced Standards). Cooperation in a multipolar multicultural community requires the development of strong intercultural competences, and this process remains limited in most institutions. These limits of international scientific cooperation can be observed through different markers, particularly the difficult and limited production of ISO standards (International Organization for Standardization) and the relatively low SCIENTI scores (Scientific Cooperation Internationalization Effort & Network Test & Index) of the specialized dental literature, particularly in comparison to the most significant medical literature. However, as an analytical tool to assess the scientific international cooperation effort between fields and periods, the SCIENTI screening system also highlighted a significant increase of the internationalization effort in the last years in the best dental biomaterials publications. Finally, an internationalization of higher education and research perspective is a very important approach to assess the evolution of the dental biomaterial science and highlights very clearly the future endeavors of this field, particularly the impact and interferences of private entities and companies in the development of this corpus of knowledge. It also reveals that the concept of independent not-for-profit Cooperation Internationalization Effort Literature (CIEL), in the various informal forms that can be found worldwide around diverse leaderships, is the best perspective for a better science and understanding of molecular, cellular and pharmaceutical aspects of biomaterials in dentistry and oral and maxillofacial surgery