Histocompatibility-2 system in wild mice

Six semicongenic lines carrying differentt haplotypes on the background of strain C57BL/10Sn (B10.t strains) and a (B10 ×T/t ⁰) F₁ hybrid were tested against one another in the mixed lymphocyte reaction (MLR) and cell-mediated lymphocytotoxicity (CML) assays. In every instance, the MLR results paralleled those of the CML typing: strain combinations giving a positive result in one assay gave a positive result in the second; combinations in which no response was observed in the MLR assay also failed to kill target cells specifically in the CML assay. Furthermore, the MLR and CML results were concordant with the results of the serological typing of these strains, as reported previously by us. The combined results suggest sharing ofH-2 hyplotypes between B10.t¹² and B10.t³², between B10.t⁶ and B10.t^w1, and between B10.t^w2 and (B10. ×T/t ⁰) F₁. These data support the conclusion, reached in our previous publication, that members of the samet-complementation group, with few exceptions, shareH-2 haplotypes.     

Evidence for a fifth (G) region in theH-2 complex of the mouse

Antisera (B10.129×A)F₁ anti-P and (B10×A)F₁ anti-B10.P contain antibodies that define, in the PVP hemagglutination test, an antigen originally described as G or H-2.7. Of the independentH-2 haplotypes, the H-2.7 antigen is present inf, j, k, p, ands. In addition, the antisera also contain a weak cytotoxic antibody, distinct from anti-H-2.7. The cytotoxic antibody reacts with antigens controlled by theK orI regions. The hemagglutinating H-2.7 antibody does not have cytotoxic activity. The genetic determinant coding for antigen H-2.7 can be mapped into the chromosomal segment between theS andD regions. The H-2.7 antigen thus serves as a marker for a new region of theH-2 complex. The locus coding for antigen H-2.7 is designatedH-2 G and the correspondingH-2 regionG. The H-2.7 antigen has a tissue distribution distinct from that of the H-2 antigens controlled by theK orD regions. So far it could be detected primarily on erythrocytes.     

Ueber eine neue Art der GattungFissidens

Ohne Zusammenfassung     

Assessment of the potential bactericide effect of self‐cleaning floors: a proposed protocol

The antibacterial properties of self‐cleaning coatings are based on bactericide nanoparticles (NPs). Ecotoxicity of these NPs have been assessed mostly in suspension, using standard bioassays. Here a protocol is proposed to test actual coating samples, using the Vibrio fischeri bioluminescence inhibition bioassay. The protocol was designed to test bactericide properties of specially coated PVC floors being used in hospital environments under quasinatural conditions, such as prolonged exposure or room temperature. To take into consideration that the light output of the bacteria under prolonged exposure naturally changes, a correction factor is proposed.     

Ancient saltern metagenomics: tracking changes in microbes and their viruses from the underground to the surface

Microbial communities in hypersaline underground waters derive from ancient organisms trapped within the evaporitic salt crystals and are part of the poorly known subterranean biosphere. Here, we characterized the viral and prokaryotic assemblages present in the hypersaline springs that dissolve Triassic-Keuper evaporite rocks and feed the Añana Salt Valley (Araba/Alava, Basque Country, Spain). Four underground water samples (around 23% total salinity) with different levels of exposure to the open air were analysed by means of microscopy and metagenomics. Cells and viruses in the spring water had lower concentrations than what are normally found in hypersaline environments and seemed to be mostly inactive. Upon exposure to the open air, there was an increase in activity of both cells and viruses as well as a selection of phylotypes. The underground water was inhabited by a rich community harbouring a diverse set of genes coding for retinal binding proteins. A total of 35 viral contigs from 15 to 104 kb, representing partial or total viral genomes, were assembled and their evolutionary changes through the spring system were followed by SNP analysis and metagenomic island tracking. Overall, both the viral and the prokaryotic assemblages changed quickly upon exposure to the open air conditions.     

Temperament and Character in the Child and Adolescent Twin Study in Sweden (CATSS): Comparison to the General Population,and Genetic Structure Analysis

Background

The Child and Adolescent Twin Study in Sweden (CATSS) is an on-going, large population-based longitudinal twin study. We aimed (1) to investigate the reliability of two different versions (125-items and 238-items) of Cloninger''s Temperament and Character Inventory (TCI) used in the CATSS and the validity of extracting the short version from the long version, (2) to compare these personality dimensions between twins and adolescents from the general population, and (3) to investigate the genetic structure of Cloninger''s model.

Method

Reliability and correlation analyses were conducted for both TCI versions, 2,714 CATSS-twins were compared to 631 adolescents from the general population, and the genetic structure was investigated through univariate genetic analyses, using a model-fitting approach with structural equation-modeling techniques based on same-sex twin pairs from the CATSS (423 monozygotic and 408 dizygotic pairs).

Results

The TCI scores from the short and long versions showed comparable reliability coefficients and were strongly correlated. Twins scored about half a standard deviation higher in the character scales. Three of the four temperament dimensions (Novelty Seeking, Harm Avoidance, and Persistence) had strong genetic and non-shared environmental effects, while Reward Dependence and the three character dimensions had moderate genetic effects, and both shared and non-shared environmental effects.

Conclusions

Twins showed higher scores in character dimensions compared to adolescents from the general population. At least among adolescents there is a shared environmental influence for all of the character dimensions, but only for one of the temperament dimensions (i.e., Reward Dependence). This specific finding regarding the existence of shared environmental factors behind the character dimensions in adolescence, together with earlier findings showing a small shared environmental effects on character among young adults and no shared environmental effects on character among adults, suggest that there is a shift in type of environmental influence from adolescence to adulthood regarding character.