Crude oil impairs immune function and increases susceptibility to pathogenic bacteria in southern flounder - Fig 1

<p><b>(A) Evidence of bloody lesions seen in flounder exposed to oil.</b> Red arrows indicate observed lesions. Fish were not tagged; therefore, lesions were not enumerated. <b>(B) Survival rates in exposure treatments on Day 2 post-exposure to pathogenic bacteria <i>Vibrio anguillarum</i></b>. Bars represent average survival for three tanks per treatment and error bars represent standard error.</p

Effect of oil exposure on bacterial diversity and function.

<p><b>(A)</b> Principal Coordinates Analysis (PCoA) plot of data at the Order level from fish collected on Day 1 post-pathogen exposure calculated with a Bray-Curtis dissimilarity in R (v. 3.0.2 [2013-09-25]–“Frisbee Sailing”). Water and sediment samples were collected on Day 0 of the experiment. Lower case letters indicate locations of various bacterial orders (a-<i>Vibrio</i>, b-<i>Alcanivorax</i> sp, c-<i>Vibrio</i>, d<i>Roseobacter</i>, e-<i>Thalassolitus</i>, f-<i>Oceanobacter kriegii</i>, g-<i>Alcanivorax</i> sp, h-<i>Halolactibacillus miurensis</i>, i-<i>Cytophaga fermentans</i>, j-<i>Oceanobacter kriegii</i>). Symbols represent different tissue types (● Intestine, ▲Lower Gill, ■ Upper Gill). Ellipses represent non-oil exposed vs. oilexposed each defined by treatment labels in their centers and indicate 95% Confidence Intervals, with orange ellipses representing both oiled treatments and gray ellipses representing both nonoiled treatments. <b>(B)</b> Predictive metagenomics analysis of the intestinal bacterial taxa in Oil/Pathogen Challenged fish (compared with control fish) indicated enrichment in degradation pathways. Pathway abundance was normalized via log₂ fold change.</p

Microbial communities significantly affected by oil exposure.

<p><b>(A)</b> Comparison of the percent of Alcanivorax with <b>(B)</b> the experimental pathogen <i>Vibrio anguillarum</i> in microbiome found in the upper gill, lower gill and intestine from flounder tissue collected Day 1 post-pathogen challenge (3 fish/treatment). Mean percentage of microbiome (+/- 1 SEM) for <i>Alcanivorax</i> sp. and <i>V</i>. <i>anguillarum</i>. (C) Comparison of the relative abundance of PAH degrading bacterial groups such as Alcanivorax, Halomonas and Oceanospirillales in the gut, lower gill, upper gill, sediment and water collected Day 1 post-pathogen challenge after flounder were returned to experimental tanks and <b>(D)</b> a closer investigation comparing the relative abundance (%) of the bacterial challenge species <i>Vibrio anguillarum and other Vibrio</i> spp between water, sediment and experimental treatments sampled Day 1 post-pathogen challenge.</p

Differentially expressed transcripts in livers of flounder exposed to oil.

<p><b>(A)</b> The Venn diagram illustrates the comparison of each treatment group with the control group based on the significantly differentially expressed genes (n = 13184 response genes). <b>(B)</b> The hierarchically clustered transcript heatmap was generated using average linking distance metric of the log₂ transformed (FPKM) values. Green represents lower expression, red represents high expression compared to the controls, columns represent individual experiments (No Oil/No Pathogen (I), Pathogen/No Oil (II), Oil/No Pathogen (III), Oil/Pathogen (IV)), and rows represent transcriptional units.</p