109 research outputs found

    Knowing me, knowing you: Spontaneous use of mentalistic language for self and other in autism

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    Recent studies on mentalizing have shown that autistic individuals who pass explicit mentalizing tasks may still have difficulties with implicit mentalizing tasks. This study explores implicit mentalizing by examining spontaneous speech that is likely to contain mentalistic expressions. The spontaneous production of meta-statements provides a clear measure for implicit mentalizing that is unlikely to be learned through experience. We examined the self- and other-descriptions of highly verbally able autistic and non-autistic adults in terms of their spontaneous use of mentalistic language and meta-representational utterances through quantitative and qualitative analysis. We devised a hierarchical coding system that allowed us to study the types of statements produced in comparable conditions for the self and for a familiar other. The descriptions of autistic participants revealed less mentalistic content relating to psychological traits and meta-statements. References to physical traits were similar between groups. Within each group, participants produced a similar pattern of types of mental utterance across ‘self’ and ‘other’ conditions. This suggests that autistic individuals show a unique pattern of mental-state-representation for both self and other. Meta-statements add a degree of complexity to self- and other-descriptions and to the understanding of mental states; their reduction in autism provides evidence for implicit mentalizing difficulties

    Genome of the red alga Porphyridium purpureum

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    The limited knowledge we have about red algal genomes comes from the highly specialized extremophiles, Cyanidiophyceae. Here, we describe the first genome sequence from a mesophilic, unicellular red alga, Porphyridium purpureum. The 8,355 predicted genes in P. purpureum, hundreds of which are likely to be implicated in a history of horizontal gene transfer, reside in a genome of 19.7 Mbp with 235 spliceosomal introns. Analysis of light-harvesting complex proteins reveals a nuclear-encoded phycobiliprotein in the alga. We uncover a complex set of carbohydrate-active enzymes, identify the genes required for the methylerythritol phosphate pathway of isoprenoid biosynthesis, and find evidence of sexual reproduction. Analysis of the compact, function-rich genome of P. purpureum suggests that ancestral lineages of red algae acted as mediators of horizontal gene transfer between prokaryotes and photosynthetic eukaryotes, thereby significantly enriching genomes across the tree of photosynthetic life

    Gene Transfer from Bacteria and Archaea Facilitated Evolution of an Extremophilic Eukaryote

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    Schoenknecht G, Chen W-H, Ternes CM, et al. Gene Transfer from Bacteria and Archaea Facilitated Evolution of an Extremophilic Eukaryote. Science. 2013;339(6124):1207-1210.Some microbial eukaryotes, such as the extremophilic red alga Galdieria sulphuraria, live in hot, toxic metal-rich, acidic environments. To elucidate the underlying molecular mechanisms of adaptation, we sequenced the 13.7-megabase genome of G. sulphuraria. This alga shows an enormous metabolic flexibility, growing either photoautotrophically or heterotrophically on more than 50 carbon sources. Environmental adaptation seems to have been facilitated by horizontal gene transfer from various bacteria and archaea, often followed by gene family expansion. At least 5% of protein-coding genes of G. sulphuraria were probably acquired horizontally. These proteins are involved in ecologically important processes ranging from heavy-metal detoxification to glycerol uptake and metabolism. Thus, our findings show that a pan-domain gene pool has facilitated environmental adaptation in this unicellular eukaryote

    Metabolic adaptation of a Chlamydomonas acidophila strain isolated from acid mine drainage ponds with low eukaryotic diversity

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    © 2018 Elsevier B.V. The diversity and biological characteristics of eukaryotic communities within acid mine drainage (AMD) sites is less well studied than for prokaryotic communities. Furthermore, for many eukaryotic extremophiles the potential mechanisms of adaptation are unclear. This study describes an evaluation of eight highly acidic (pH 1.6–3.1) and one moderately acidic (pH 5.6) metal-rich acid mine drainage ponds at a disused copper mine. The severity of AMD pollution on eukaryote biodiversity was examined, and while the most species-rich site was less acidic, biodiversity did not only correlate with pH but also with the concentration of dissolved and particulate metals. Acid-tolerant microalgae were present in all ponds, including the species Chlamydomonas acidophila, abundance of which was high in one very metal-rich and highly acidic (pH 1.6) pond, which had a particularly high PO4-P concentration. The C. acidophila strain named PM01 had a broad-range pH tolerance and tolerance to high concentrations of Cd, Cu and Zn, with bioaccumulation of these metals within the cell. Comparison of metal tolerance between the isolated strain and other C. acidophila strains previously isolated from different acidic environments found that the new strain exhibited much higher Cu tolerance, suggesting adaptation by C. acidophila PM01 to excess Cu. An analysis of the metabolic profile of the strains in response to increasing concentrations of Cu suggests that this tolerance by PM01 is in part due to metabolic adaptation and changes in protein content and secondary structure
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