Effects of inbreeding and other systematic effects on fertility of Black Forest Draught horses in Germany

Background

The Black Forest Draught horse (BFDH) is an endangered German coldblood breed with its origin in the area of the Black Forest in South Germany. In this retrospective study, the influence of the inbreeding coefficient on foaling rates was investigated using records from ten breeding seasons. Due to the small population size of BFDH, the level of inbreeding is increasing and may have an effect on foaling rates.The data of the present study included all coverings reported for 1024 BFDH mares in the years 2001–2009. These mares were covered by 32 BFDH stallions from the State Stud Marbach. Data from 4534 estrus cycles was used to calculate per cycle foaling rate (CFR). Pedigree data contained all studbook data up to the foundation of the breed as early as 1836. The level of inbreeding of the mare, stallion and expected foal along with other systematic effects on CFR were analysed using a generalized linear mixed model approach. Stallion was employed as a random effect. Systematic fixed effects were month of mating, mating type, age of the mare and stallion, reproductive status of the mare and stallion line of the mare. Inbreeding coefficients of the stallion, mare and expected foal were modelled as linear covariates.

Results

The average CFR was 40.9%. The mean inbreeding coefficients of the mares, stallions and expected foals were 7.46, 7.70 and 9.66%. Mating type, age of the mare, reproductive status of the mare and stallion line of the mare had a significant effect.

Conclusions

The results showed that the mating type, stallion line of the mare, sire, age and reproductive status of the mare exerted the largest influences on CFR in BFDH. Inbreeding coefficients of the stallion, mare and expected foal were not significantly related with CFR.

     

NFkappaB activation by Fas is mediated through FADD, caspase-8, and RIP and is inhibited by FLIP

Fas (APO-1/CD95) is the prototypic death receptor, and the molecular mechanisms of Fas-induced apoptosis are comparably well understood. Here, we show that Fas activates NFkappaB via a pathway involving RIP, FADD, and caspase-8. Remarkably, the enzymatic activity of the latter was dispensable for Fas-induced NFkappaB signaling pointing to a scaffolding-related function of caspase-8 in nonapoptotic Fas signaling. NFkappaB was activated by overexpressed FLIPL and FLIPS in a cell type-specific manner. However, in the context of Fas signaling both isoforms blocked FasL-induced NFkappaB activation. Moreover, down-regulation of both endogenous FLIP isoforms or of endogenous FLIPL alone was sufficient to enhance FasL-induced expression of the NFkappaB target gene IL8. As NFkappaB signaling is inhibited during apoptosis, FasL-induced NFkappaB activation was most prominent in cells that were protected by Bcl2 expression or caspase inhibitors and expressed no or minute amounts of FLIP. Thus, protection against Fas-induced apoptosis in a FLIP-independent manner converted a proapoptotic Fas signal into an inflammatory NFkappaB-related response.     

N-terminal Gag domain required for foamy virus particle assembly and export

Among the Retroviridae, foamy viruses (FVs) exhibit an unusual way of particle assembly and a highly specific incorporation of envelope protein into progeny virions. We have analyzed deletions and point mutants of the prototypic FV gag gene for capsid assembly and egress, envelope protein incorporation, infectivity, and ultrastructure. Deletions introduced at the 3' end of gag revealed the first 297 amino acids (aa) to be sufficient for specific Env incorporation and export of particulate material. Deletions introduced at the 5' end showed the region between aa 6 and 200 to be dispensable for virus capsid assembly but required for the incorporation of Env and particle egress. Point mutations were introduced in the 5' region of gag to target residues conserved among FVs from different species. Alanine substitutions of residues in a region between aa 40 and 60 resulted in severe alterations in particle morphology. Furthermore, at position 50, this region harbors the conserved arginine that is presumably at the center of a signal sequence directing FV Gag proteins to a cytoplasmic assembly site.     

Cryphonectria radicalis: rediscovery of a lost fungus

In an attempt to isolate the ascomycete Cryphonectria parasitica (Diaporthales, Valsaceae) from dead chestnut stems, we obtained three C. radicalis strains. All three strains were isolated in areas of Switzerland with high chestnut blight incidence. To confirm our species designation, we compared the three C. radicalis strains to hypovirus (hv)-free and hv-infected C. parasitica strains. The comparison revealed several distinctive characteristics. On potato dextrose agar in the dark, the C. radicalis strains produced a fluffy mycelium and small droplets of a purple exudate giving the mycelium a light pinkish appearance. On corn meal medium in the dark, the C. radicalis strains caused a color change of the medium to purple, whereas the C. parasitica strains did not cause any color change. Ascospores from C. radicalis were significantly smaller than C. parasitica ascospores and their dimensions fit within other published size ranges. Southern hybridization analysis of the two species using nuclear and mitochondrial probes support their taxonomic separation. This separation is further supported by the lack of successful interspecific crosses. In virulence tests on chestnut trees, the C. radicalis strains exhibited very low virulence, comparable to highly hypovirulent hv-infected C. parasitica strains. Our results suggest that C. radicalis still coexists with C. parasitica although at a low frequency.     

A microsphere study on the effects of somatostatin and secretin on regional blood flow in anesthetized dogs

The endogenous peptides somatostatin and secretin are effective in the therapy of upper gastrointestinal tract bleeding and acute pancreatitis. The clinical effects may be partly brought about by changes in the regional blood flow. To evaluate the effects of somatostatin (50 and 100 μg/min over 6–8 min) and secretin (0.1 and 0.5 U · kg^?1 · min^?1 over 3–5 min) on tissue blood flow, particularly of the gastrointestinal tract, the tracer microsphere reference sample method was used in anesthetized dogs.Infusion of somatostatin significantly diminished gastric and pancreatic blood flow whereas no changes of duodenal and ileal blood flow could be obtained. Blood flow through spleen, kidneys and adrenal glands was increased but no changes were observed in the blood flow of other tissues. Cardiac hemodynamics remained unchanged.Secretin increased the blood flow of the duodenum, the kidneys and the adrenal glands and diminished gastric blood flow without changing pancreatic, ileal, hepatic, pulmonary and muscle blood flow. Cerebral, pituitary and myocardial blood flow was increased by a higher dose of secretin. It also evoked a slight but significant positive ino- and chronotropic effect. Since secretin and somatostatin differ in their respective effects on gastrointestinal blood flow it is suggested that the previously reported beneficial effects of both peptides on upper gastrointestinal bleeding cannot solely be attributed to changes in regional blood flow.     

Development of Adenoviral Delivery Systems to Target Hepatic Stellate Cells In Vivo

Hepatic stellate cells (HSCs) are known as initiator cells that induce liver fibrosis upon intoxication or other noxes. Deactivation of this ongoing remodeling process of liver parenchyma into fibrotic tissue induced by HSCs is an interesting goal to be achieved by targeted genetic modification of HSCs. The most widely applied approach in gene therapy is the utilization of specifically targeted vectors based on Adenovirus (Ad) serotype 5. To narrow down the otherwise ubiquitous tropism of parental Ad, two modifications are required: a) ablating the native tropism and b) redirecting the vector particles towards a specific entity solely present on the cells of interest. Therefore, we designed a peptide of the nerve growth factor (NGF_p) with specific affinity for the p75 neurotrophin receptor (p75NTR) present on HSCs. Coupling of this NGF_p to vector particles was done either via chemical conjugation using bifunctional polyethylene glycol (PEG) or, alternatively, by molecular bridging with a fusion protein specific for viral fiber knob and p75NTR. Both Ad vectors transmit the gene for the green fluorescent protein (GFP). GFP expression was monitored in vitro on primary murine HSCs as well as after systemic administration in mice with healthy and fibrotic livers using intravital fluorescence microscopy. Coupling of NGF_p to Ad via S11 and/or PEGylation resulted in markedly reduced liver tropism and an enhanced adenoviral-mediated gene transfer to HSCs. Transduction efficiency of both specific Ads was uniformly higher in fibrotic livers, whereas Ad.GFP-S11-NGF_p transduce activated HSCs better than Ad.GFP-PEG-NGF_p. These experiments contribute to the development of a targeted gene transfer system to specifically deliver antifibrotic compounds into activated HSCs by systemically applied adenoviral vector modified with NGF_p.