Karyological studies on some species of the families Echinostomatidae and Plagiorchiidae and aspects of chromosome evolution in trematodes

The morphometric characteristics of the chromosomes and the variability of the C-heterochromatin blocks in the trematodes Echinoparyphium aconiatum, E. recurvatum, Echinostoma revolutum, E. echinatum, Hypoderaeum conoideum, Isthmiophora melis, Paryphostomum radiatum, Neoacanthoparyphium echinatoides, Plagiorchis maculosus and Opisthioglyphe ranae are determined. The terminal and subterminal localisation of the centromere is a characteristic of the taxa examined. Typical two-arm chromosomes are rare. The karyotype of the examined trematodes is asymmetrical, and this asymmetry is a result of differences in the lengths of the chromosome arms. It is proved that the regression of the lengths of the chromosome arms has a linear character with a similar angle of slope in the different species. Centric fusion and unreciprocal translocations are accepted as contributing significantly to chromosome changes. A hypothesis on the possible mechanism of chromosome changes in the trematode karyotype is proposed.     

Summer feeding strategy of Spanish ibexCapra pyrenaica and domestic sheepOvis aries in south-eastern Spain

The feeding strategies of the Spanish ibexCapra pyrenaica Schinz, 1838 and sheepOvis aries Linnaeus, 1758 during summer in the alpine area of Sierra Nevada in south-eastern Spain were compared. The degree of vegetation use by the two ungulates, food availability, diet composition, species selection indices and the effect of plant availability and chemical composition on diet selection were analysed. The available biomass of herbaceous and woody resources was 87 and 13%, respectively. The degree of use was 15% for herbaceous vegetation and 10.3% for woody vegetation. The most used species were those with moderate amounts in diet composition of both ruminants. The main plant groups consumed by Spanish ibex were graminoids (57.5%), shrubs (20.5%) and chamaephytes (14.3%). Sheep consumed graminoids (41.6%), forbs (32.3%) and chamaephytes (20.9%). There was a significant correlation between the two diets, with an overlap of 56.3%. The highest indices of selection were found in items with moderate-low availability and which comprised moderate levels in the diet composition of the two species. Spanish ibex mainly selected diet according to availability, while sheep selection depended on protein content. The ibex consumed cell wall-rich resources such as grasses and shrubs, while the sheep consumed higher quality feed and includes more forbs in its diet.     

Spatial distribution patterns of the hyporheic invertebrate communities in a polluted river in Romania

The purpose of this study was to examine the sensitivity, in a field situation, of the hyporheic fauna to pollution by heavy metals and also to test the use of oxidative stress enzymes produced by this fauna as a sensitive indicator of oxidative stress generated by chemical contamination. This was done by surveying the patterns of distribution, structure, and composition of hyporheic invertebrate communities in one of the most polluted rivers in Romania. Twelve permanent sampling stations with differing water qualities were established along a 180 km transect of the Arie? River. Data on hyporheic invertebrate abundance and richness, chemistry of the surface and hyporheic water and interstitial suspended particles were analyzed via multifactorial analyses. In the downstream, more polluted stations, epigean species were less abundant and hyporheic communities, especially macrocrustaceans and oligochetes, became dominant. The higher levels of hyporheic invertebrate biodiversity in the moderately polluted stations compared to highly polluted, and the increase of the number of some hyporheos (especially macrocrustaceans) in the moderately polluted stations, suggested that the hyporheic fauna was more tolerant of heavy metal pollution than the surface water fauna of the area. However, the different richness and abundance of hyporheic fauna in sites of similar water chemistry suggested that additional factors, such as sediment structure are shaping the spatial distribution of hyporheic fauna. Strong correlations between superoxide dismutase (SOD) activity in pooled tissues extracts and some chemical parameters suggest that oxidative stress enzymes may prove to be sensitive indicators of chemical pollution in hyporheic zones.     

Viral dosing of influenza A infection reveals involvement of RIPK3 and FADD,but not MLKL

RIPK3 was reported to play an important role in the protection against influenza A virus (IAV) in vivo. Here we show that the requirement of RIPK3 for protection against IAV infection in vivo is only apparent within a limited dose range of IAV challenge. We found that this protective outcome is independent from RIPK3 kinase activity and from MLKL. This shows that platform function of RIPK3 rather than its kinase activity is required for protection, suggesting that a RIPK3 function independent of necroptosis is implicated. In line with this finding, we show that FADD-dependent apoptosis has a crucial additional effect in protection against IAV infection. Altogether, we show that RIPK3 contributes to protection against IAV in a narrow challenge dose range by a mechanism that is independent of its kinase activity and its capacity to induce necroptosis.Subject terms: Cell death, Cell death and immune response, Infection     

Trichome micromorphology of the Chinese-Himalayan genus <Emphasis Type="Italic">Colquhounia</Emphasis> (Lamiaceae), with emphasis on taxonomic implications

Trichome micromorphology of leaves and young stems of nine taxa (including four varieties) of Colquhounia were examined using light and scanning microscopy. Two basic types of trichomes were recognized: eglandular and glandular. Eglandular trichomes are subdivided into simple and branched trichomes. Based on the number of cells and trichome configuration, simple eglandular trichomes are further divided into four forms: unicellular, two-celled, three-celled and more than three-celled trichomes. Based on branching configuration, the branched eglandular trichomes can be separated into three forms: biramous, stellate and dendroid. Glandular trichomes can be divided into two subtypes: capitate and peltate glandular trichomes. Results from this study of morphological diversity of trichomes within Colquhounia lend insight into infrageneric classification and species relationships. Based on the presence of branched trichomes in C. elegans, this species should be transferred from Colquhounia sect. Simplicipili to sect. Colquhounia. We provide a taxonomic key to species of Chinese Colquhounia based on trichome morphology and other important morphological traits.     

Molecular Defects in the Motor Adaptor BICD2 Cause Proximal Spinal Muscular Atrophy with Autosomal-Dominant Inheritance

The most common form of spinal muscular atrophy (SMA) is a recessive disorder caused by deleterious SMN1 mutations in 5q13, whereas the genetic etiologies of non-5q SMA are very heterogeneous and largely remain to be elucidated. In a Bulgarian family affected by autosomal-dominant proximal SMA, we performed genome-wide linkage analysis and whole-exome sequencing and found a heterozygous de novo c.320C>T (p.Ser107Leu) mutation in bicaudal D homolog 2 (Drosophila) (BICD2). Further analysis of BICD2 in a cohort of 119 individuals with non-5q SMA identified a second de novo BICD2 mutation, c.2321A>G (p.Glu774Gly), in a simplex case. Detailed clinical and electrophysiological investigations revealed that both families are affected by a very similar disease course, characterized by early childhood onset, predominant involvement of lower extremities, and very slow disease progression. The amino acid substitutions are located in two interaction domains of BICD2, an adaptor protein linking the dynein molecular motor with its cargo. Our immunoprecipitation and localization experiments in HeLa and SH-SY5Y cells and affected individuals’ lymphoblasts demonstrated that p.Ser107Leu causes increased dynein binding and thus leads to accumulation of BICD2 at the microtubule-organizing complex and Golgi fragmentation. In addition, the altered protein had a reduced colocalization with RAB6A, a regulator of vesicle trafficking between the Golgi and the endoplasmic reticulum. The interaction between p.Glu744Gly altered BICD2 and RAB6A was impaired, which also led to their reduced colocalization. Our study identifies BICD2 mutations as a cause of non-5q linked SMA and highlights the importance of dynein-mediated motility in motor neuron function in humans.