Horizontal-Acquisition of a Promiscuous Peptidoglycan-Recycling Enzyme Enables Aphids To Influence Symbiont Cell Wall Metabolism

Most enzymes are capable of performing biologically irrelevant side reactions. During evolution, promiscuous enzyme activities may acquire new biological roles, especially after horizontal gene transfer to new organisms.

A Novel SXT/R391 Integrative and Conjugative Element Carries Two Copies of the bla NDM-1 Gene in Proteus mirabilis

The occurrence of carbapenemase-producing Proteus mirabilis , especially those strains producing NDM-1 and its variants, is a major public health concern worldwide. The integrative conjugative element (ICE) plays an important role in horizontal acquisition of resistance genes.

Genome mosaicism in field strains of Mycoplasma bovis as footprints of in-host horizontal chromosomal transfer

Horizontal gene transfer was long thought to be marginal in Mollicutes, but the capacity of some of these wall-less bacteria to exchange large chromosomal regions has been recently documented. Mycoplasma chromosomal transfer (MCT) is an unconventional mechanism that relies on the presence of a functional integrative conjugative element (ICE) in at least one partner and involves the horizontal acquisition of small and large chromosomal fragments from any part of the donor genome, which results in progenies composed of an infinitive variety of mosaic genomes. The present study focuses on Mycoplasma bovis, an important pathogen of cattle responsible for major economic losses worldwide. By combining phylogenetic tree reconstructions and detailed comparative genome analyses of 36 isolates collected in Spain (2016-2018) we confirmed the mosaic nature of 16 field isolates and mapped chromosomal transfers exchanged between their hypothetical ancestors. This study provides evidence that MCT can take place in the field, most likely during co-infections by multiple strains. Because mobile genetic elements (MGEs) are classical contributors of genome plasticity, the presence of phages, insertion sequences (ISs) and ICEs was also investigated. Data revealed that these elements are widespread within the M. bovis species and evidenced classical horizontal transfer of phages and ICEs in addition to MCT. These events contribute to wide-genome diversity and reorganization within this species and may have a tremendous impact on diagnostic and disease control.

Exploring The Horizontal Acquisition Of Transnational Identity In Intercultural Relationships In Toronto

While identity shift in the context of migration has been studied in depth, questions of identity in those who have close, love-based relationships with international migrants or descendants of migrants remain underrepresented in the literature. Theoretically framing the research in a cultural studies and constructivist perspective, this study explores the extent to which individuals in intercultural relationships take on components of their partners’ transnational identities and how this process occurs. Interviews were conducted with seven individuals in intercultural relationships with first or second-generation immigrant partners. They explored how an individual’s identity shifts in the context of their relationship to reflect their partner’s transnational identity. The findings demonstrate that individuals embrace components of their partner’s transnational identity through discussion and interaction with both their partner and their partner’s family, suggesting that non-migrant individuals with no familial ties to another region in the world can also engage in transnationalism.

Exploring The Horizontal Acquisition Of Transnational Identity In Intercultural Relationships In Toronto

While identity shift in the context of migration has been studied in depth, questions of identity in those who have close, love-based relationships with international migrants or descendants of migrants remain underrepresented in the literature. Theoretically framing the research in a cultural studies and constructivist perspective, this study explores the extent to which individuals in intercultural relationships take on components of their partners’ transnational identities and how this process occurs. Interviews were conducted with seven individuals in intercultural relationships with first or second-generation immigrant partners. They explored how an individual’s identity shifts in the context of their relationship to reflect their partner’s transnational identity. The findings demonstrate that individuals embrace components of their partner’s transnational identity through discussion and interaction with both their partner and their partner’s family, suggesting that non-migrant individuals with no familial ties to another region in the world can also engage in transnationalism.

Genome evolution of a non-parasitic secondary heterotroph, the diatom Nitzschia putrida

Secondary loss of photosynthesis is observed across almost all plastid-bearing branches of the eukaryotic tree of life. However, genome-based insights into the transition from a phototroph into a secondary heterotroph have so far only been revealed for parasitic species. Free-living organisms can yield unique insights into the evolutionary consequence of the loss of photosynthesis, as the parasitic lifestyle requires specific adaptations to host environments. Here we report on the diploid genome of the free-living diatom Nitzschia putrida (35 Mbp), a non-photosynthetic osmotroph whose photosynthetic relatives contribute ca. 40% of net oceanic primary production. Comparative analyses with photosynthetic diatoms revealed that a combination of genes loss, the horizontal acquisition of genes involved in organic carbon degradation, a unique secretome and the rapid divergence of conserved gene families involved in cell wall and extracellular metabolism appear to have facilitated the lifestyle of a non-parasitic, free-living secondary heterotroph.

The Bigness Complex Redux: Horizontal Ownership Concentration and Efficiency Conundrums

This cliometric study evaluates efficiency outcomes from America’s telecommunications sector acquisitions, based on data for 1988–2001, as the sector’s horizontal acquisition processes have repeated themselves. Sector ownership has been comprehensively reconcentrated. Concepts from the size and structural capital literatures enable defining mechanisms to establish causality between horizontal ownership influence and efficiency. For the measure of size, smaller-sized firms display positive efficiency impacts, while medium-sized firms display lower performance than average and large-sized entities display substantially lower performance. Entities experiencing a lesser level of structural capital influence enjoy better performance, while entities experiencing a medium level of structural capital influence experience lower performance than average and entities experiencing a high level of structural capital influence experience much lower efficiency. The evidence implies that negative motivations associated with size and power acquisition may be spilt over to acquired entities, and increasing negative size impact suggests these motives have strengthened as larger controlling entities have brought more units under their ambit. Restraining concentration is a fundamental policy concern to restore competitive economy fundamentals and prevent ruining America’s entrepreneurial spirit.

Horizontally Acquired Homologs of Xenogeneic Silencers: Modulators of Gene Expression Encoded by Plasmids, Phages and Genomic Islands

Acquisition of mobile elements by horizontal gene transfer can play a major role in bacterial adaptation and genome evolution by providing traits that contribute to bacterial fitness. However, gaining foreign DNA can also impose significant fitness costs to the host bacteria and can even produce detrimental effects. The efficiency of horizontal acquisition of DNA is thought to be improved by the activity of xenogeneic silencers. These molecules are a functionally related group of proteins that possess affinity for the acquired DNA. Binding of xenogeneic silencers suppresses the otherwise uncontrolled expression of genes from the newly acquired nucleic acid, facilitating their integration to the bacterial regulatory networks. Even when the genes encoding for xenogeneic silencers are part of the core genome, homologs encoded by horizontally acquired elements have also been identified and studied. In this article, we discuss the current knowledge about horizontally acquired xenogeneic silencer homologs, focusing on those encoded by genomic islands, highlighting their distribution and the major traits that allow these proteins to become part of the host regulatory networks.

Comparative genomic analysis of the secondary flagellar (flag-2) system in the order Enterobacterales

Background The order Enterobacterales encompasses a broad range of metabolically and ecologically versatile bacterial taxa, most of which are motile by means of peritrichous flagella. Flagellar biosynthesis has been linked to a primary flagella locus, flag -1, encompassing ~ 50 genes. A discrete locus, flag -2, encoding a distinct flagellar system, has been observed in a limited number of enterobacterial taxa, but its function remains largely uncharacterized. Results and Discussion Comparative genomic analyses showed that orthologous flag -2 loci are present in 592/4,028 taxa belonging to 5/8 and 31/76 families and genera, respectively, in the order Enterobacterales. Furthermore, the presence of only the outermost flag- 2 genes in many taxa suggests that this locus was far more prevalent and has subsequently been lost through gene deletion events. The flag -2 loci range in size from ~3.4 to 81.1 kilobases and code for between five and 102 distinct proteins. The discrepancy in size and protein number can be attributed to the presence of cargo gene islands within the loci. Evolutionary analyses revealed a complex evolutionary history for the flag -2 loci, representing ancestral elements in some taxa, while showing evidence of recent horizontal acquisition in other enterobacteria. Conclusions The flag -2 flagellar system is a fairly common, but highly variable feature among members of the Enterobacterales. Given the energetic burden of flagellar biosynthesis and functioning, the prevalence of a second flagellar system suggests it plays important biological roles in the enterobacteria and we postulate on its potential role as locomotory organ or as secretion system.