Project description:Ex vivo intestines from 15-20 g ballan wrass (Labrus bergylta) were administered a bolus (lipid, protein, inert matter or empty control) before being mounted in oxygenated physiological buffer inside a glass vial. The intestinal motility patterns were documented with time lapse imaging for 14 hours. The images were used to construct spatio-temporal maps for gut motility analysis; i.e. to determine the speed, amplitude, frequency, travelled distance, direction, and initiation site of waves of muscle contractions. The experiments were repeated for RNA sampling and deep seq analysis. Gene expression analysis showed that intestines administered intact lipids clustered closer to the empty intestines compared to those given hydrolyzed lipids.
Project description:Ballan wrasse (Labrus bergylta, Ascanius 1767) are cleaner fish cultured in northern Europe to remove sea lice from farmed Atlantic salmon (Salmo salar, Linnaeus 1758). Despite increasing appreciation for the importance of the microbiota on the phenotypes of vertebrates including teleosts, the microbiota of wrasse eggs has yet to be described. Therefore, the aim of this present study was to describe the bacterial component of the microbiota of ballan wrasse eggs shortly after spawning and at 5 days, once the eggs had undergone a routine incubation protocol that included surface disinfection steps in a common holding tank. Triplicate egg samples were collected from each of three spawning tanks and analysis of 16S rRNA gene sequences revealed that 88.6% of reads could be identified to 186 taxonomic families. At Day 0, reads corresponding to members of the Vibrionaceae, Colwelliaceae and Rubritaleaceae families were detected at greatest relative abundances. Bacterial communities of eggs varied more greatly between tanks than between samples deriving from the same tank. At Day 5, there was a consistent reduction in 16S rRNA gene sequence richness across the tanks. Even though the eggs from the different tanks were incubated in a common holding tank, the bacterial communities of the eggs from the different tanks had diverged to become increasingly dissimilar. This suggests that the disinfection and incubation exerted differential effects of the microbiota of the eggs from each tank and that the influence of the tank water on the composition of the egg microbiota was lower than expected. This first comprehensive description of the ballan wrasse egg bacterial community is an initial step to understand the role and function of the microbiota on the phenotype of this fish. In future, mass DNA sequencing methods may be applied in hatcheries to screen for pathogens and as a tool to assess the health status of eggs.
Project description:Stomach-less fishes comprise a diverse phylogenetic group within the teleosts indicating that the organ has been lost several times during evolution. In the present project we have combined Illumina short read platform with the PacBio long read platform to sequence the ballan wrasse (Labrus bergylta) genome and its intestinal transcriptome. The genome was applied to investigate the elimination and conservation of genes related to stomach function and appetite regulation in wrasse in relation to the loss of stomach in this species. We have sequenced the transcriptome of four intestinal segments from six ballan wrasse (Labrus bergylta) for the purpose of identifying possible functional organization along the wrasse intestine. The transcriptomic reads were mapped against the newly assembled genome. The analysis revealed a transcriptional gradient showing genes involved in nutrient digestion and uptake being highly expressed in the anterior intestine and declining towards the end of the intestine. The last segment, hind-gut, had the most distinct expression between the four segments with increased expression of genes coding for proteins involved in lysosomal activity, antigen presenting and vitamin b12 uptake. Overall, our results suggests that the wrasse entire digestive system is comparable to the small intestine of mammals with regards to gene expression missing both a stomach and colon. Gene expression related to colon in humans such as MS4A12 were found in the last segment. The genome analysis also confirmed the lack of genes coding for gastric proteins such as gastric lipase, pepsin, gastrin and ghrelin. Although ghrelin is not only related to stomach, ghrelin was missing in all stomach-less fish species with the exception of cyprinid. Ghrelin is currently the only known orexigenic hormone.
Project description:Background: Farm exposures in early life reduce the risks for childhood allergic diseases and asthma. There is less information about how farm exposures relate to respiratory illnesses and mucosal immune development. Objective: We hypothesized that children raised in farm environments have a lower incidence of viral illnesses over the first two years of life than non-farm children. We also analyzed between farm exposures or respiratory illnesses were related to patterns of nasal cell gene expression. Methods: The Wisconsin Infant Study Cohort (WISC) birth cohort enrolled farm and non-farm pregnant women from central Wisconsin. Parents reported prenatal farm and other environmental exposures. Illness frequency and severity were assessed using illness diaries and periodic surveys. Nasopharyngeal cell gene expression at age two years was compared to farm exposure and respiratory illness history. Results: There was a higher rate of respiratory illnesses in the non-farm vs. farm group (rate ratio 0.82 [0.69,0.97], p=0.020), but no significant differences in wheezing illnesses. There was a stepwise reduction in rates of respiratory illnesses in children exposed at least weekly to 0, 1, or ≥2 animals (p=0.006). In analyzing nasal cell gene expression, farm exposures and preceding respiratory illnesses were positively related to gene signatures for mononuclear cells and innate and antimicrobial responses. Conclusions: Children exposed to farms and farm animals had lower rates of respiratory illnesses over the first two years of life. Both farm exposures and preceding respiratory illnesses were associated with increased innate immune responses, suggesting that these exposures stimulate mucosal immune responses to reduce subsequent illness frequency.