Final Summary Post

Hello everyone! I have essentially completed my paper and have an outline of my poster for the research symposium, so thought it was time for my final wrap-up post. I will definitely make edits to both my paper and my poster before the symposium as my project advisor and I find new resources and look at the data in different ways, but for this final summary I will give a brief overview of what I did and describe the results section of my paper.

As a reminder, my project aimed to use fluorescently tagged zebrafish as a model of the vascular effects of Fetal Alcohol Spectrum Disorder. For each of the three weeks I was on campus doing research, I treated zebrafish with varying percentages of ethanol at varying times post-fertilization. I collected heart rate, phenotype, and intersegmental vessel data in order to gather a holistic picture of the effects of alcohol on the vasculature and angiogenesis. In the end, I divided my results into two categories as follows:

  1. Alcohol results in gross phenotypic defects and changes in heart rate.

This section describes my findings in terms of phenotype classifications (explained in an earlier post) and heart rate calculations. I found that alcohol caused phenotypic and heart defects, but heart rate was not always significantly affected. By 48 hours post-fertilization, nearly all of the treatment embryos qualified at least as a mild phenotype. Overall, with a few exceptions, as alcohol treatment increased, so did the percentage of embryos with more affected phenotypes. In terms of heart rate, the average bpm of treatment doses 1.5% and above were significantly different from the control at both 2 hpf and 4 hpf, and at 2 hpf the 1% dose was significantly different from the control. There were some other significant differences between groups, but the small dataset (average of 7.9 heart rate values in each group, with a range of 3-15) and differences between dechorionated zebrafish and those still within chorions contribute to large SEMs, so it is difficult to confidently describe the significance of the treatment percentage. More data would allow me to perform more accurate statistical tests and better demonstrate the effect of alcohol on zebrafish heart rate–potentially a task for a future project!

  1. Alcohol treatment results in vascular defects.

This section dives into intersegmental vessels, looking at ISV length as a metric for demonstrating the effect of alcohol on vascular development. In control zebrafish, all ISVs were fully formed, and blood cell nuclei were visible within the vessels. As treatment dosage percentages increased, ISVs appeared thinner and blood cell nuclei were less present. At the most severe alcohol dosages, some ISVs were incomplete or missing. ISV length was shown to decrease as alcohol treatment percentage increased, both at 2 hpf and 4 hpf treatment times. At 2 hpf, all treatment groups were significantly different from the control, and at 4 hpf only the 1% group was not significantly different. In addition, at 2 hpf, the 1.5% and 2% groups were significantly different from the 1% group. At 4 hpf, the 1.25%, 1.5% and 2% groups were all significantly different from the 1% treatment, and the 1.25% and 1.5% groups showed significant differences from each other. This demonstrated that alcohol does have an effect on ISV length, and the extent of effect is often related to the treatment percentage.

Overall, the data I found and the ANOVA/Tukey HSD statistics were very promising in showing the vascular effect of alcohol with the selected zebrafish model. In the future, I would like to go deeper and look for reasons for the defects, such as molecular or heart morphology explanations. I’d also like to attempt rescue experiments using compounds to try to rescue the phenotype of zebrafish treated with alcohol. All in all, there is a lot of room to expand this first “trial run” project, and I am excited for what the future holds in terms of better understanding FASD and ways to treat it.

Thank you for following my journey this summer—I will have my paper and poster to share with you all at the symposium this fall! See you then!