Moss, A. S. | bioRxiv Science

bioRxiv2024

Effects of Feed Processing Type, Protein Source, and Environmental Salinity on Litopenaeus vannamei Feeding Behaviour

In an 8-week trial, the effects of feed processing types (extruded vs. steamed pellets) and protein source (soya/pea vs. fish meal) on Litopenaeus vannamei were studied under 30 ppt (first 30 days) and 5 ppt (last 15 days) salinity conditions. Diets included D1-SE soya/pea extruded, D2-SS soya/pea steamed, D3-FE fishmeal extruded, and D4 (FS) fishmeal steamed pellets. No significant weight differences were observed. Survival rates (80-97% at 30 ppt) decreased at reduced salinity and were significantly higher for shrimp fed steamed pellets (D2:80.00%, D4:76.67%) compared to extruded (D1: 50.00%, p<0.05). Shrimp fed D2-SS and D4-FS diets had increased lipid content (6.79%, 6.36%, p<0.05). Significantly lower lysine and isoleucine were noted in D2-SS. Behaviourally, at 30 ppt, D3-FE attracted significantly more shrimp (84.72%) than D1-SE (74.49%) and D2-SS (75.70%, p<0.05). Click analysis showed D1-SE and D2-SS with the shortest durations (17.97, 17.24ms, respectively), and D3-FE and D4-FS the longest (20.10, 23.89ms, respectively, p<0.05). Click frequency was also significantly higher in fishmeal-based diets, whereas the number of clicks was higher in shrimp fed extruded feed. Overall, extruded pellets and fishmeal diets were more favourable. These findings emphasize the importance of tailored feed strategies that consider nutritional content, feed physical properties and environmental factors for optimal shrimp feeding.

zoology↗

bioRxiv2022

Immunological landscape of human lymph nodes during ex vivo measles virus infection

In humans, lymph nodes are the primary site of measles virus (MeV) replication. To understand the immunological events that occur at this site, we infected human lymphoid tissue explants using a pathogenic strain of MeV that expresses GFP. We found that MeV infected between 5-15% of cells across donors. Using single cell RNA-Seq (scRNA-Seq) and flow cytometry, we found that while most of the 29 cell populations identified in the lymphoid culture were susceptible to MeV, there was a broad preferential infection of B cells and reduced infection of T cells. Further subsetting of T cells revealed that this reduction may be driven by the decreased infection of naive T cells. Transcriptional changes in infected B cells were dominated by an interferon stimulated gene (ISG) signature. To determine which of these ISGs were most substantial, we evaluated the proteome of MeV-infected Raji cells by mass spectrometry. We found that IFIT1, IFIT2, IFIT3, ISG15, CXCL10, MX2, and XAF1 proteins were the most highly induced, and positively correlated with their expression in the transcriptome. These data provide insight into the immunological events that occur in lymph nodes during infection and may lead to the development of therapeutic interventions.

immunology↗