Project description:Frass is the by-product of the larval meal industry and includes larval waste, exoskeleton sheds, and residual feed ingredients. Experimental frass was derived from the larvae of black solder flies (Hermetia illucens) fed distillers dried grains. A 10-week study was conducted to evaluate the effect of dietary levels of frass on the global gene expression of channel catfish, Ictalurus punctatus. Three diets containing 0, 50, and 300 g frass per kg diet were fed to channel catfish (5.24 ± 0.04 g) in quadruplicate aquaria to apparent satiation twice daily. Intestine (n=12 in pools of 3) and liver (n=12 in pools of 3) tissues were taken from fish at the end of the trial and processed for high-throughput Illumina RNA sequencing (RNAseq). Pairwise comparisons identified both up- and down-regulated genes in frass diets compared to no frass controls.
Project description:The black soldier fly (Hermetia illucens) is important in antimicrobial peptides (AMP) research due to its exposure to diverse microbial environments. However, the impact of different fungal exposures on AMP abundance in H. illucens has not been thoroughly explored. Our study focused on basal conditions and interactions with three fungi: the non-pathogenic Candida tropicalis (isolated from larval gut), Saccharomyces cerevisiae, and the pathogenic Beauveria bassiana. Using RNA-seq and LC-MS/MS, we found that under standard conditions, the majority of AMPs belonged to the Lysozyme, Cecropin, and Defensin classes, with Defensins exhibiting the highest quantification levels. Exposure to any of the fungi upregulated AMP gene expression, indicating immune activation. Notably, exposure to C. tropicalis and B. bassiana led to notable downregulation of AMPs in H. illucens larvae compared to S. cerevisiae, suggesting these fungi may suppress or modulate the host immune response to aid their survival and colonization. The immune response of H. illucens larvae revealed that S. cerevisiae and B. bassiana trigger similar AMP pathways, whereas C. tropicalis elicits a distinct response with upregulation of Defensins and Cecropins. Lysozymes, known for their antibacterial and antifungal activity, were upregulated in response to S. cerevisiae and B. bassiana, but downregulated with C. tropicalis, potentially facilitating fungal survival in the larvae’s gut. This suggests that C. tropicalis adapts to reduce immune pressure, while B. bassiana may suppress AMPs to persist. Understanding these mechanisms opens possibilities for leveraging AMPs in combating C. tropicalis, which is implicated in human diseases.
2024-11-19 | GSE272202 | GEO
Project description:Hermetia illucens Gut and Frass Metatranscriptome
Project description:The present study was conducted to investigate the effect of graded levels of black soldier fly larvae (BSFL) (Hermetia illucens) meal and BSFL paste in extruded diets for Atlantic salmon (Salmo salar). A total of 1260 Atlantic salmon with 34 g of mean initial weight were randomly distributed into 21 fiberglass tanks and fed (n=3) with seven extruded isolipidic and isonitrogenous diets for seven weeks. The experimental diets consisted of a positive control diet based on fishmeal, soy protein concentrate, corn gluten, faba bean and fish oil (Control_1); three diets with increased levels of full lipid BSFL meal, substituting 6.25% (6.25_IM), 12.5% (12.5_IM) and 25% (25_IM) of the protein content of Control_1; two diets with increased levels of full lipid BSFL paste, substituting 3.7% (3.7_IP) and 6.7% (6.7_IP); and of protein from Control_1 and a negative a control with 0.84 % of formic acid (Control_2). We investigate the effect of diets on growth performance, mmune response and health.