Male-male competition and female choice in brown trout

In some salmonid species, the females have been assumed to choose their mates on the size of the male's adipose fin. This hypothesis was tested in a stream water aquarium, in which 19 brown trout, Salmo trutta, females were allowed to choose between two males of the same body size but with different adipose fin sizes. The two males were separated from each other in cages. After the female had started to prepare her nest close to one of them, the males were released and allowed to fight each other for the opportunity to spawn. Out of 19 females, 14 prepared a nest closest to the male with the larger adipose fin. However, only six of the 14 females spawned with this male. Males that spawned were more dominant (i.e. were more likely to win fights). When the female spawned with the male she chose, he was less aggressive towards her than when she spawned with the other male. There were no significant differences in the plasma levels of testosterone (T) and 11-ketotestosterone (11-KT) between the chosen males and those not chosen. However, the dominant males had significantly higher plasma levels of T and 11-KT both before and after the experiment. The results support the view that female brown trout exhibit mate choice, but their choice is overruled by male-male competition. Copyright 1999 The Association for the Study of Animal Behaviour.     

19p13.3 aberrations are associated with dysmorphic features and deviant psychomotor development

Here, we describe 2 patients with de novo genomic imbalances of 19p13.3. Using high-resolution microarray analysis, we detected a 1.25-Mb deletion in one patient and a 0.81- Mb duplication in another. The resulting phenotypes are quite different; one is a 2-year-old boy with macrocephaly and normal growth, while the other is a 9-year-old boy with microcephaly and growth retardation since birth. Both have dysmorphic features and psychomotor developmental delay. This report gives evidence of the effect of small aberrations of chromosome 19 and describes the phenotypes arising from a duplication and deletion of the same location at 19p13.3.     

Comparing RADseq and microsatellites to infer complex phylogeographic patterns,an empirical perspective in the Crucian carp,Carassius carassius,L.

The conservation of threatened species must be underpinned by phylogeographic knowledge. This need is epitomized by the freshwater fish Carassius carassius, which is in decline across much of its European range. Restriction site‐associated DNA sequencing (RADseq) is increasingly used for such applications; however, RADseq is expensive, and limitations on sample number must be weighed against the benefit of large numbers of markers. This trade‐off has previously been examined using simulation studies; however, empirical comparisons between these markers, especially in a phylogeographic context, are lacking. Here, we compare the results from microsatellites and RADseq for the phylogeography of C. carassius to test whether it is more advantageous to genotype fewer markers (microsatellites) in many samples, or many markers (SNPs) in fewer samples. These data sets, along with data from the mitochondrial cytochrome b gene, agree on broad phylogeographic patterns, showing the existence of two previously unidentified C. carassius lineages in Europe: one found throughout northern and central‐eastern European drainages and a second almost exclusively confined to the Danubian catchment. These lineages have been isolated for approximately 2.15 m years and should be considered separate conservation units. RADseq recovered finer population structure and stronger patterns of IBD than microsatellites, despite including only 17.6% of samples (38% of populations and 52% of samples per population). RADseq was also used along with approximate Bayesian computation to show that the postglacial colonization routes of C. carassius differ from the general patterns of freshwater fish in Europe, likely as a result of their distinctive ecology.     

Induction of Potent Neutralizing Antibody Responses by a Designed Protein Nanoparticle Vaccine for Respiratory Syncytial Virus

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Monitoring Climate Sensitivity Shifts in Tree-Rings of Eastern Boreal North America Using Model-Data Comparison

The growth of high-latitude temperature-limited boreal forest ecosystems is projected to become more constrained by soil water availability with continued warming. The purpose of this study was to document ongoing shifts in tree growth sensitivity to the evolving local climate in unmanaged black spruce (Picea mariana (Miller) B.S.P.) forests of eastern boreal North America (49°N–52°N, 58°W–82°W) using a comparative study of field and modeled data. We investigated growth relationships to climate (gridded monthly data) from observed (50 site tree-ring width chronologies) and simulated growth data (stand-level forest growth model) over 1908–2013. No clear strengthening of moisture control over tree growth in recent decades was detected. Despite climate warming, photosynthesis (main driver of the forest growth model) and xylem production (main driver of radial growth) have remained temperature-limited. Analyses revealed, however, a weakening of the influence of growing season temperature on growth during the mid- to late twentieth century in the observed data, particularly in high-latitude (> 51.5°N) mountainous sites. This shift was absent from simulated data, which resulted in clear model-data desynchronization. Thorough investigations revealed that desynchronization was mostly linked to the quality of climate data, with precipitation data being of particular concern. The scarce network of weather stations over eastern boreal North America (> 51.5°N) affects the accuracy of estimated local climate variability and critically limits our ability to detect climate change effects on high-latitude ecosystems, especially at high altitudinal sites. Climate estimates from remote sensing could help address some of these issues in the future.     

Crucian carp (Carassius carassius (L.)), an anonymous fish with great skills

Ichthyological Research - The crucian carp (Carassius carassius) is a cyprinid fish with its natural distribution in Europe and the western part of Asia. Due to its hardiness and unique ability to...     

The influence of curli, a MHC-I-binding bacterial surface structure, on macrophage-T cell interactions

Escherichia coli express thin surface fimbriae called curli which bind soluble matrix proteins and major histocompatibility complex (MHC)-I molecules. The present study addressed the ability of purified curli or curliated E. coli to influence peptide presentation on MHC-I, T cell proliferation and bacterial uptake by macrophages. In vitro studies with curli-proficient E. coli YMel and the isogenic curli-deficient strain YMel-1, both expressing the model antigen Crl-OVA, showed that curli expression by E. coli does not appear to influence the efficiency by which the bacteria are processed by murine macrophages for OVA(257-264) presentation on K(b). Furthermore, curli expression by E. coli did not influence the binding of exogenously added OVA(257-264) peptide to K(b) on the surface of prefixed macrophages. In addition, neither curliated nor non-curliated heat-killed bacteria influenced proliferation of either murine or human T cells stimulated with anti-CD3. Finally, curliated E. coli adhered to and were internalized by macrophages from C57BL/6 and MHC-I-deficient TAP1(-/-) mice equally well. Together these studies show that curli expression by E. coli does not appear to influence phagocytic processing of bacteria expressing Crl-OVA for OVA(257-264)/K(b) presentation, the binding of exogenously added OVA(257-264) to K(b) or T cell proliferation. In addition, although curli expression by E. coli enhances bacterial interaction with macrophages, curli interaction with MHC-I does not significantly contribute to this adherence.