Background/Aims: Allergen absorption by epithelia may play an important role in downstream immune responses. Transport mechanisms that can bypass Peyer's patches include transcellular and paracellular transport. The capacity of an allergen to cross via these means can modulate downstream processing of the allergen by the immune system. The aim of this study was to investigate allergen-epithelial interactions of peanut allergens with the human intestinal epithelium. Methods: We achieved this using the human Caco-2 cell culture model, exposed to crude peanut extract. Western and immunofluorescence analysis were used to identify the cellular and molecular changes of peanut extract on the intestinal epithelium. Results: Following exposure of Caco-2 cells to peanut extract, binding of the peanut allergens Ara h 1 and Ara h 2 to the apical cellular membrane and transcytosis across the monolayers were observed. Additionally, the co-localisation of the transmembrane tight junction proteins occludin, JAM-A and claudin-1, with the intracellular adhesion protein ZO-1 was modified. Conclusion: Disruption of Caco-2 barrier integrity through tight junction disruption may enable movement of peanut proteins across the intestinal epithelium. This accounts for peanut's increased allergenicity, compared to other food allergens, and provides an explanation for the potency of peanut allergens in immune response elicitation.

Background: Variants that regulate transcription, such as expression quantitative trait loci (eQTL), have shown enrichment in genome-wide association studies (GWAS) for mammalian complex traits. However, no study has reported eQTL in sheep, although it is an important agricultural species for which many GWAS of complex meat traits have been conducted. Using RNA sequence data produced from liver and muscle from 149 sheep and imputed whole-genome single nucleotide polymorphisms (SNPs), our aim was to dissect the genetic architecture of the transcriptome by associating sheep genotypes with three major molecular phenotypes including gene expression (geQTL), exon expression (eeQTL) and RNA splicing (sQTL). We also examined these three types of eQTL for their enrichment in GWAS of multi-meat traits and fatty acid profiles. Results: Whereas a relatively small number of molecular phenotypes were significantly heritable (h ² > 0, P  < 0.05), their mean heritability ranged from 0.67 to 0.73 for liver and from 0.71 to 0.77 for muscle. Association analysis between molecular phenotypes and SNPs within ± 1 Mb identified many significant cis-eQTL (false discovery rate, FDR < 0.01). The median distance between the eQTL and transcription start sites (TSS) ranged from 68 to 153 kb across the three eQTL types. The number of common variants between geQTL, eeQTL and sQTL within each tissue, and the number of common variants between liver and muscle within each eQTL type were all significantly ( P < 0.05) larger than expected by chance. The identified eQTL were significantly ( P  < 0.05) enriched in GWAS hits associated with 56 carcass traits and fatty acid profiles. For example, several geQTL in muscle mapped to the FAM184B gene, hundreds of sQTL in liver and muscle mapped to the CAST gene, and hundreds of sQTL in liver mapped to the C6 gene. These three genes are associated with body composition or fatty acid profiles. Conclusions: We detected a large number of significant eQTL and found that the overlap of variants between eQTL types and tissues was prevalent. Many eQTL were also QTL for meat traits. Our study fills a gap in the knowledge on the regulatory variants and their role in complex traits for the sheep model.

Aims: Starvation stress is a condition that nonstarter lactic acid bacteria (NSLAB) normally encounter. This study was aimed to investigate starvation-induced proteins in Lactobacillus casei during stationary growth phase. Methods and Results: The impact of carbohydrate starvation on L. casei GCRL163 was investigated using two different media (a modified de Man, Rogosa and Sharpe broth and a semi-defined medium). Cells were grown in the presence of excess lactose (1%) or starvation (0%) and differences in the patterns of one-dimensional sodum dodecyl sulfate–polyacrylamide gel electrophoresis and two-dimensional electrophoresis of the cytosolic protein fractions were investigated. Differentially regulated proteins were identified by MALDI-TOF/TOF mass spectrometry. Many differentially regulated proteins were enzymes of various metabolic pathways involved in carbohydrate metabolism to yield energy. Differences in protein expression were also observed in the two culture conditions tested in this experiment. Conclusion: Numerous glycolytic enzymes were differentially regulated under lactose starvation. The differential expression of these glycolytic enzymes suggests a potential survival strategy under harsh growth conditions (i.e. lactose starvation). Significance and Impact of the Study: This paper reports improved understanding of stress responses and survival mechanism of NSLAB under lactose-depleted cheese-ripening condition. This knowledge of how NSLAB bacteria adapt to lactose starvation could be applied to predict the performances of bacteria in other industrial applications.

Efficient liveweight gain is an important component of profitable livestock systems. In cattle, studies of residual feed intake (RFI) suggest that there are behavioural differences between efficient and inefficient animals; more efficient animals have less frequent, larger feed events. There is limited understanding of the association between feeding behaviour and feed conversion efficiency (measured as RFI) in sheep. We hypothesised that more efficient sheep would have lower daily number of meals but larger meal size than would less efficient sheep and that feeding behaviour would be repeatable between measurements conducted using the same sheep at different ages. Feeding behaviour was monitored at post-weaning (average 311 days) and hogget (average 533 days) age in a single cohort of maternal composite 2014-born ewes undergoing feed-efficiency testing. Feed intake (kg/day) and daily feeding behaviour (meal number, meal size and eating rate) were recorded by using automated feeders. Feed intake was recorded daily for a minimum of 40 days (mean 41 days), following a 14-day adaptation period. Animals were fed a pelleted hay-based diet, with liveweight measured three times per week. At both ages of measurement, a positive (P < 0.01) linear relationship was established between average daily number of meals and RFI. In these cohorts, as daily number of meals increased, RFI became more positive (less efficient). Meal size (kg DM) was also related to RFI (P < 0.05) when measured at the hogget age, with meal size decreasing with an increasing RFI (less efficient animals had smaller meals). These analyses suggest that sheep feeding behaviour, and in particular daily meal number, is associated with feed efficiency.