Milken Institute School of Public Health Poster Presentations (Marvin Center & Video)

Title

FISHing with Rat Sperm; the effect of glyphosate toxicity on sex chromosome aneuploidy in rats

Poster Number

42

Document Type

Poster

Status

Staff

Abstract Category

Environmental and Occupational Health

Keywords

Glyphosate; Aneuploidy; Sperm

Publication Date

4-2017

Abstract

Background: Glyphosate (N-(Phosphonomethyl-glycine)) is one of the most frequently used chemicals in herbicides worldwide; and is ubiquitous in the environment and food supply. Recent studies have identified glyphosate as a potential endocrine disrupting chemical (EDC). EDCs have been associated with a decrease in testicular function, including increases in aneuploidy, an abnormal number of chromosomes in sperm cells. The presence of aneuploidy in sperm cells can contribute to early embryo loss as well as children with Klinefelter and Turner syndromes. This study investigates the impact of glyphosate in its chemical form and in the form of the commercial herbicide Roundup®, on testicular function.

Methods: Triple-probe fluorescence in situ hybridization (FISH) is used to identify sex chromosome disomy (XX, YY, XY) in sperm cells. The FISH method being developed for this study is based on three peer-reviewed studies using rat sperm FISH to ascertain aneuploidy, and our current lab protocol for human sperm FISH. For methods development we used 14 samples of epididymal sperm from 8 non-study rats extracted in differing volumes of sodium citrate buffer. Our protocol includes removal and separation of the sperm tail for enhanced imaging, swelling of the nucleus and denaturation of the DNA to provide ideal conditions for hybridization of custom-made probes for chromosomes X, Y and an autosomal control. The probes are enumerated using an adaptation of the human sperm procedure for imaging and nuclei are scored semi-automatically using a Leica DMi8 inverted fluorescent microscope and specialized analysis software. To investigate the effects of glyphosate, we collected 54 epididymal sperm samples from rats in three groups; (I) no treatment, (II) treatment with glyphosate, (III) treatment with Roundup®. Animals in treatment groups were dosed through drinking water at the acceptable daily intake for humans in the USA, 1.75mg per kilogram of body weight per day.

Conclusions: Preliminary data on aneuploidy frequencies, specifically XX, XY, YY, and total disomy, and comparisons between dosed and non-dosed animals will be described and observations about chemical impacts on sperm abnormalities will be provided.

Creative Commons License

Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.

Open Access

1

Comments

Poster to be presented at GW Annual Research Days 2017.

This document is currently not available here.

Share

COinS
 

FISHing with Rat Sperm; the effect of glyphosate toxicity on sex chromosome aneuploidy in rats

Background: Glyphosate (N-(Phosphonomethyl-glycine)) is one of the most frequently used chemicals in herbicides worldwide; and is ubiquitous in the environment and food supply. Recent studies have identified glyphosate as a potential endocrine disrupting chemical (EDC). EDCs have been associated with a decrease in testicular function, including increases in aneuploidy, an abnormal number of chromosomes in sperm cells. The presence of aneuploidy in sperm cells can contribute to early embryo loss as well as children with Klinefelter and Turner syndromes. This study investigates the impact of glyphosate in its chemical form and in the form of the commercial herbicide Roundup®, on testicular function.

Methods: Triple-probe fluorescence in situ hybridization (FISH) is used to identify sex chromosome disomy (XX, YY, XY) in sperm cells. The FISH method being developed for this study is based on three peer-reviewed studies using rat sperm FISH to ascertain aneuploidy, and our current lab protocol for human sperm FISH. For methods development we used 14 samples of epididymal sperm from 8 non-study rats extracted in differing volumes of sodium citrate buffer. Our protocol includes removal and separation of the sperm tail for enhanced imaging, swelling of the nucleus and denaturation of the DNA to provide ideal conditions for hybridization of custom-made probes for chromosomes X, Y and an autosomal control. The probes are enumerated using an adaptation of the human sperm procedure for imaging and nuclei are scored semi-automatically using a Leica DMi8 inverted fluorescent microscope and specialized analysis software. To investigate the effects of glyphosate, we collected 54 epididymal sperm samples from rats in three groups; (I) no treatment, (II) treatment with glyphosate, (III) treatment with Roundup®. Animals in treatment groups were dosed through drinking water at the acceptable daily intake for humans in the USA, 1.75mg per kilogram of body weight per day.

Conclusions: Preliminary data on aneuploidy frequencies, specifically XX, XY, YY, and total disomy, and comparisons between dosed and non-dosed animals will be described and observations about chemical impacts on sperm abnormalities will be provided.