Presentation Title

Use of FETAX to Assess the Teratogenic Effects of Nonylphenol and Polyoxyethyleneamine on Developing Xenopus laevis Embryos

Faculty Mentor

Caryl Forristall

Start Date

17-11-2018 8:30 AM

End Date

17-11-2018 10:30 AM

Location

CREVELING 105

Session

POSTER 1

Type of Presentation

Poster

Subject Area

biological_agricultural_sciences

Abstract

The Roundup component polyoxyethyleneamine (POEA) and the environmental estrogen nonylphenol (4NP) are both surfactant compounds found in high levels in the Central Valley due to their use in agriculture and other industries. Surfactants’ ability to reduce a products surface tension allows them to spread far from their original application site. Evidence from Lyons ‘ lab shows that 4NP is present in concentrations as high as 0.04 µM in snow and water in the eastern Sierra Nevada mountain range. These pollutant concentrations and the declining amphibian population specific to the Eastern Sierra warrants the assessment of the dangers of these human made pollutants on developing amphibian embryos. To determine the teratogenic effects of 4NP and POEA, the Frog Embryo Teratogenesis Assay Xenopus (FETAX) protocol was used. Xenopus laevis embryos of various stages were treated with different concentrations of the test compounds for 96 hours. It was found that embryos at stage 48+ (feeding tadpole) were more sensitive to 4NP than embryos at blastula and neurula stages, with concentrations of 5uM sufficient to kill all embryos. POEA experiments demonstrated stage 48+ sensitivity (to doses higher than 3.35 mg/L) as well. Preliminary evidence suggests a second time of sensitivity at neurula. No consistent teratogenic effect was seen with either 4NP or POEA. Future studies will focus on potential interactions between POEA and 4NP in both controlled laboratory settings and in natural aquatic environments.

Summary of research results to be presented

Embryos in various stages of development were placed in different concentrations of 4NP and POEA to determine if the teratogenic effects were species specific or stage specific. Embryos staged at 48+ at the beginning of the 96 hours 4NP treatment were found to be more sensitive than embryos treated at earlier stage. The lethal concentration of 4NP on earlier stages was found to be 10um 4NP. These results correspond to the literature which found the lethal concentration to be between 15.8um 4NP and 24.5um 4NP (Mann, 2000). Embryos treated with 4NP for 96 hours beginning at stage 48+ were more sensitive than the earlier stages. Embryos staged at Neurula were more sensitive to POEA than embryos staged at Blastula, ~33 and ~40. These studies found that both 4NP and POEA affect certain stages of development differently and are not species specific.

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Nov 17th, 8:30 AM Nov 17th, 10:30 AM

Use of FETAX to Assess the Teratogenic Effects of Nonylphenol and Polyoxyethyleneamine on Developing Xenopus laevis Embryos

CREVELING 105

The Roundup component polyoxyethyleneamine (POEA) and the environmental estrogen nonylphenol (4NP) are both surfactant compounds found in high levels in the Central Valley due to their use in agriculture and other industries. Surfactants’ ability to reduce a products surface tension allows them to spread far from their original application site. Evidence from Lyons ‘ lab shows that 4NP is present in concentrations as high as 0.04 µM in snow and water in the eastern Sierra Nevada mountain range. These pollutant concentrations and the declining amphibian population specific to the Eastern Sierra warrants the assessment of the dangers of these human made pollutants on developing amphibian embryos. To determine the teratogenic effects of 4NP and POEA, the Frog Embryo Teratogenesis Assay Xenopus (FETAX) protocol was used. Xenopus laevis embryos of various stages were treated with different concentrations of the test compounds for 96 hours. It was found that embryos at stage 48+ (feeding tadpole) were more sensitive to 4NP than embryos at blastula and neurula stages, with concentrations of 5uM sufficient to kill all embryos. POEA experiments demonstrated stage 48+ sensitivity (to doses higher than 3.35 mg/L) as well. Preliminary evidence suggests a second time of sensitivity at neurula. No consistent teratogenic effect was seen with either 4NP or POEA. Future studies will focus on potential interactions between POEA and 4NP in both controlled laboratory settings and in natural aquatic environments.