Atrazine induced hermaphroditism
Download
1 / 109

Atrazine-Induced Hermaphroditism - PowerPoint PPT Presentation


  • 624 Views
  • Uploaded on
  • Presentation posted in: Pets / Animals

Atrazine-Induced Hermaphroditism . By: Michelle Lin . What is Atrazine?. What is Atrazine?. Systematic herbicide that blocks photosynthesis. What is Atrazine?. Systematic herbicide that blocks photosynthesis

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha

Download Presentation

Atrazine-Induced Hermaphroditism

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Atrazine-Induced Hermaphroditism

By: Michelle Lin


What is Atrazine?


What is Atrazine?

  • Systematic herbicide that blocks photosynthesis


What is Atrazine?

  • Systematic herbicide that blocks photosynthesis

  • Metabolized to four hydroxyatrazine compounds & to three chlorinated atrazine compounds.


What is Atrazine?

  • Systematic herbicide that blocks photosynthesis

  • Metabolized to four hydroxyatrazine compounds & to three chlorinated atrazine compounds.

    • Predominate metabolites found in plants


What is Atrazine?

  • Systematic herbicide that blocks photosynthesis

  • Metabolized to four hydroxyatrazine compounds & to three chlorinated atrazine compounds.

    • Predominate metabolites found in plants

    • Desethylated atrazine, desisopropyl atrazine, & diaminochlorotriazine (DACT) predominate in animal tissues, & in soils and water


What is Atrazine?

  • Systematic herbicide that blocks photosynthesis

  • Metabolized to four hydroxyatrazine compounds & to three chlorinated atrazine compounds.

    • Predominate metabolites found in plants

    • Desethylated atrazine, desisopropyl atrazine, & diaminochlorotriazine (DACT) predominate in animal tissues, & in soils and water

  • commonly detected pesticide in ground and surface water


What is Atrazine?

  • Systematic herbicide that blocks photosynthesis

  • Metabolized to four hydroxyatrazine compounds & to three chlorinated atrazine compounds.

    • Predominate metabolites found in plants

    • Desethylated atrazine, desisopropyl atrazine, & diaminochlorotriazine (DACT) predominate in animal tissues, & in soils and water

  • commonly detected pesticide in ground and surface water

  • detected in streams, rivers, groundwater, and reservoirs isrelated directly to both its volume of usage, and its tendency to persist in soils and move with water.


It’s a pesticide, so what?


It’s a pesticide, so what?

  • Most widely used herbicide in the world


It’s a pesticide, so what?

  • Most widely used herbicide in the world

  • Most common contaminant in ground and surface waters


It’s a pesticide, so what?

  • Most widely used herbicide in the world

  • Most common contaminant in ground and surface waters

  • About 64 to 75 million lbs of active ingredient are applied per year


It’s a pesticide, so what?

  • Most widely used herbicide in the world

  • Most common contaminant in ground and surface waters

  • About 64 to 75 million lbs of active ingredient are applied per year

  • Three-fourths of all field corn & sorghum are treated with atrazine annually for weed control


It’s a pesticide, so what?

  • Most widely used herbicide in the world

  • Most common contaminant in ground and surface waters

  • About 64 to 75 million lbs of active ingredient are applied per year

  • Three-fourths of all field corn & sorghum are treated with atrazine annually for weed control

  • Also used on sugarcane, wheat, guava, macadamia nuts orchard grass and hay


What does Atrazine cause?


What does Atrazine cause?

  • Hermaphroditism in American Leopard Frogs (Rana pipiens)


What does Atrazine cause?

  • Hermaphroditism in American Leopard Frogs (Rana pipiens)

    • 21 ppb atrazine exposure in 48 hrs can results in severe gonadal dygenesis in African clawed frogs (Xenopus laevis)


What does Atrazine cause?

  • Hermaphroditism in American Leopard Frogs (Rana pipiens)

    • 21 ppb atrazine exposure in 48 hrs can results in severe gonadal dygenesis in African clawed frogs (Xenopus laevis)

    • at concentrations of 0.1 ppb, atrazine induces hermaphroditism


The experiment


The experiment

  • Leopard frogs obtained from Sensiba March, Brown County, Wisconsin then shipped to the University of California Berkeley


The experiment

  • Leopard frogs obtained from Sensiba March, Brown County, Wisconsin then shipped to the University of California Berkeley

  • Larvae were treated by immersion with nominal concentrations of 0, 0.1, or 25 ppb atrazine (98% pure)


The experiment

  • Leopard frogs obtained from Sensiba March, Brown County, Wisconsin then shipped to the University of California Berkeley

  • Larvae were treated by immersion with nominal concentrations of 0, 0.1, or 25 ppb atrazine (98% pure)

  • Atrazine was predissolved in ethanol, and all treatments contained 0.0036% ethanol


The experiment

  • Leopard frogs obtained from Sensiba March, Brown County, Wisconsin then shipped to the University of California Berkeley

  • Larvae were treated by immersion with nominal concentrations of 0, 0.1, or 25 ppb atrazine (98% pure)

  • Atrazine was predissolved in ethanol, and all treatments contained 0.0036% ethanol

  • Exposed throughout larval period from 2 days posthatching until complete tail reabsorbtion.


The experiment

  • Leopard frogs obtained from Sensiba March, Brown County, Wisconsin then shipped to the University of California Berkeley

  • Larvae were treated by immersion with nominal concentrations of 0, 0.1, or 25 ppb atrazine (98% pure)

  • Atrazine was predissolved in ethanol, and all treatments contained 0.0036% ethanol

  • Exposed throughout larval period from 2 days posthatching until complete tail reabsorbtion.

  • All dosing and analyses were conducted blindly with color-coded tanks and treatments.


The experiment continued


The experiment continued

  • At metamorphosis, each animal was weighed and measured then euthanized in 0.2% benzocaine, fixed in Bouin’s fixative, and preserved in 70% ethanol until further analysis.


The experiment continued

  • At metamorphosis, each animal was weighed and measured then euthanized in 0.2% benzocaine, fixed in Bouin’s fixative, and preserved in 70% ethanol until further analysis.

  • Sex of all individuals were determined based on gross gonadal morphology using a Nikon SMZ 10A


The experiment continued

  • At metamorphosis, each animal was weighed and measured then euthanized in 0.2% benzocaine, fixed in Bouin’s fixative, and preserved in 70% ethanol until further analysis.

  • Sex of all individuals were determined based on gross gonadal morphology using a Nikon SMZ 10A

  • Tissues dissected and dehydrated in graded alcohols followed by infiltration with Histoclear and paraffin


The experiment continued

  • At metamorphosis, each animal was weighed and measured then euthanized in 0.2% benzocaine, fixed in Bouin’s fixative, and preserved in 70% ethanol until further analysis.

  • Sex of all individuals were determined based on gross gonadal morphology using a Nikon SMZ 10A

  • Tissues dissected and dehydrated in graded alcohols followed by infiltration with Histoclear and paraffin

  • Serial histological sections cut at 8µm through entire gonad


The experiment continued

  • At metamorphosis, each animal was weighed and measured then euthanized in 0.2% benzocaine, fixed in Bouin’s fixative, and preserved in 70% ethanol until further analysis.

  • Sex of all individuals were determined based on gross gonadal morphology using a Nikon SMZ 10A

  • Tissues dissected and dehydrated in graded alcohols followed by infiltration with Histoclear and paraffin

  • Serial histological sections cut at 8µm through entire gonad

  • Slides were stained in Mallory’s trichrome stain and images of gonads were recorded


The collection sites


The collection sites

  • Localities based on atrazine use determined by sales


The collection sites

  • Localities based on atrazine use determined by sales

  • Countries with <0.4kg/km² atrazine use were chosen as potential control sites


The collection sites

  • Localities based on atrazine use determined by sales

  • Countries with <0.4kg/km² atrazine use were chosen as potential control sites

  • >9.3 kg/km² were chosen as potential atrazine-exposed sites


The collection sites

  • Localities based on atrazine use determined by sales

  • Countries with <0.4kg/km² atrazine use were chosen as potential control sites

  • >9.3 kg/km² were chosen as potential atrazine-exposed sites


Collection sites continued


Collection sites continued

  • Sampled in Utah on 15 July 2001 and moved eastward


Collection sites continued

  • Sampled in Utah on 15 July 2001 and moved eastward

  • Collected 100 animals in 8 sites for a total of 800 animals


Collection sites continued

  • Sampled in Utah on 15 July 2001 and moved eastward

  • Collected 100 animals in 8 sites for a total of 800 animals

  • Selected small individuals in an attempt to sample newly metamorphosed animals


Collection sites continued

  • Sampled in Utah on 15 July 2001 and moved eastward

  • Collected 100 animals in 8 sites for a total of 800 animals

  • Selected small individuals in an attempt to sample newly metamorphosed animals

  • Animals were euthanized in benzocaine, fixed in Bouin’s fixative for 48 hours and preserved in 70% ethanol


Collection sites continued

  • Sampled in Utah on 15 July 2001 and moved eastward

  • Collected 100 animals in 8 sites for a total of 800 animals

  • Selected small individuals in an attempt to sample newly metamorphosed animals

  • Animals were euthanized in benzocaine, fixed in Bouin’s fixative for 48 hours and preserved in 70% ethanol

  • They were measured and sex was determined and histological analysis was conducted on the gonads of 20 males from each site and a subset of females from each site


Chemical Analysis


Chemical Analysis

  • At each site, 100mL of water was collected


Chemical Analysis

  • At each site, 100mL of water was collected

    • Frozen on dry ice


Chemical Analysis

  • At each site, 100mL of water was collected

    • Frozen on dry ice

    • Atrazine levels were determined


Chemical Analysis

  • At each site, 100mL of water was collected

    • Frozen on dry ice

    • Atrazine levels were determined

    • Water sample extracted in organic solvent followed by aqueous/organic extraction


Chemical Analysis

  • At each site, 100mL of water was collected

    • Frozen on dry ice

    • Atrazine levels were determined

    • Water sample extracted in organic solvent followed by aqueous/organic extraction

  • Analyzed by liquid chromatography/mass spectrophotometry using daughter ion


Chemical Analysis

  • At each site, 100mL of water was collected

    • Frozen on dry ice

    • Atrazine levels were determined

    • Water sample extracted in organic solvent followed by aqueous/organic extraction

  • Analyzed by liquid chromatography/mass spectrophotometry using daughter ion

  • Positive controls contained mixtures of pesticides at both 0.1 and 10.0 ppb


Chemical Analysis

  • At each site, 100mL of water was collected

    • Frozen on dry ice

    • Atrazine levels were determined

    • Water sample extracted in organic solvent followed by aqueous/organic extraction

  • Analyzed by liquid chromatography/mass spectrophotometry using daughter ion

  • Positive controls contained mixtures of pesticides at both 0.1 and 10.0 ppb

  • detection limits at 0.1 ppb


Gonadal analysis on lab-animals


Gonadal analysis on lab-animals

  • Control animals sexually differentiated at metamorphosis


Gonadal analysis on lab-animals

  • Control animals sexually differentiated at metamorphosis

    • earliest males to metamorphose had solid testicular lobules


Gonadal analysis on lab-animals

  • Control animals sexually differentiated at metamorphosis

    • earliest males to metamorphose had solid testicular lobules

    • testes were more differentiated (contained more distinct tubules and germ cells) anteriorly than posteriorly


Gonadal analysis on lab-animals

  • Control animals sexually differentiated at metamorphosis

    • earliest males to metamorphose had solid testicular lobules

    • testes were more differentiated (contained more distinct tubules and germ cells) anteriorly than posteriorly


Gonadal analysis continued


Gonadal analysis continued

  • Animals that metamorphosed later had open lobules


Gonadal analysis continued

  • Animals that metamorphosed later had open lobules

    • Contained both primary spermatogonia and spermatids


Gonadal analysis continued

  • Animals that metamorphosed later had open lobules

    • Contained both primary spermatogonia and spermatids

    • Females had numerous oocytes in their gonads and a central ovarian cavity


Gonadal analysis continued

  • Animals that metamorphosed later had open lobules

    • Contained both primary spermatogonia and spermatids

    • Females had numerous oocytes in their gonads and a central ovarian cavity


The Results


The Results

  • Atrazine-treated males (0.1 and 25 ppb) were sexually differentiated at metamorphosis


The Results

  • Atrazine-treated males (0.1 and 25 ppb) were sexually differentiated at metamorphosis

    • 36 and 12% of males treated with 0.1 and 25 ppb atrazine suffered gonadal dysgenesis


The Results

  • Atrazine-treated males (0.1 and 25 ppb) were sexually differentiated at metamorphosis

    • 36 and 12% of males treated with 0.1 and 25 ppb atrazine suffered gonadal dysgenesis

      • Gonadal dysgenesis- underdeveloped testes with poorly structured, closed lobules or no lobules at all and low to absent germ cells


The Results

  • Atrazine-treated males (0.1 and 25 ppb) were sexually differentiated at metamorphosis

    • 36 and 12% of males treated with 0.1 and 25 ppb atrazine suffered gonadal dysgenesis

      • Gonadal dysgenesis- underdeveloped testes with poorly structured, closed lobules or no lobules at all and low to absent germ cells


The Results Continued


The Results Continued

  • 29% of the 0.1 ppb-treated animals and 8% that were treated with 25 ppb displayed varying degrees of sex reversal


The Results Continued

  • 29% of the 0.1 ppb-treated animals and 8% that were treated with 25 ppb displayed varying degrees of sex reversal

  • Testicular lobules of sex-reversed males contained oocytes


The Results Continued

  • 29% of the 0.1 ppb-treated animals and 8% that were treated with 25 ppb displayed varying degrees of sex reversal

  • Testicular lobules of sex-reversed males contained oocytes

  • Males that metamorphosed later contained large number of oocytes


The Results Continued

  • 29% of the 0.1 ppb-treated animals and 8% that were treated with 25 ppb displayed varying degrees of sex reversal

  • Testicular lobules of sex-reversed males contained oocytes

  • Males that metamorphosed later contained large number of oocytes

  • Males that underwent complete sex reversal had gonads almost completely filled with oocytes and only a limited number of lobules remained.


The Results Continued

  • 29% of the 0.1 ppb-treated animals and 8% that were treated with 25 ppb displayed varying degrees of sex reversal

  • Testicular lobules of sex-reversed males contained oocytes

  • Males that metamorphosed later contained large number of oocytes

  • Males that underwent complete sex reversal had gonads almost completely filled with oocytes and only a limited number of lobules remained.

  • No observable effects in atrazine-treated females


Observations in the Wild


Observations in the Wild

  • Chemical analysis of water revealed none of the sites were atrazine free


Observations in the Wild

  • Chemical analysis of water revealed none of the sites were atrazine free

    • Only one site (Juab County, Utah) contained <0.2 ppb atrazine levels


Observations in the Wild

  • Chemical analysis of water revealed none of the sites were atrazine free

    • Only one site (Juab County, Utah) contained <0.2 ppb atrazine levels

    • Sites in Utah and Wyoming did not have detectable levels of atrazine metabolites


Observations in the Wild

  • Chemical analysis of water revealed none of the sites were atrazine free

    • Only one site (Juab County, Utah) contained <0.2 ppb atrazine levels

    • Sites in Utah and Wyoming did not have detectable levels of atrazine metabolites

  • All sites with atrazine sales exceeding 0.4 kg/km² and contaminant levels that exceeded 0.2 ppb had males that displayed sex reversal similar to those that resulted from laboratory


Observations in the Wild Continued


Observations in the Wild Continued

  • Site 3, North Platte River in Wyoming had most advanced cases of hermaphroditism


Observations in the Wild Continued

  • Site 3, North Platte River in Wyoming had most advanced cases of hermaphroditism

    • 92% testicular oocytes


Observations in the Wild Continued

  • Site 3, North Platte River in Wyoming had most advanced cases of hermaphroditism

    • 92% testicular oocytes

    • Advanced stages of complete sex reversal


Observations in the Wild Continued

  • Site 3, North Platte River in Wyoming had most advanced cases of hermaphroditism

    • 92% testicular oocytes

    • Advanced stages of complete sex reversal

  • All other sites varied in frequency and severity of gonadal abnormalities


Observations in the Wild Continued

  • Site 3, North Platte River in Wyoming had most advanced cases of hermaphroditism

    • 92% testicular oocytes

    • Advanced stages of complete sex reversal

  • All other sites varied in frequency and severity of gonadal abnormalities


Contaminant levels


Contaminant levels


The Collection Sites


The Collection Sites


Contaminant levels continued


Contaminant levels continued


What does all this mean?


What does all this mean?

  • Atrazine exposure disrupts gonadal development in exposed larvae


What does all this mean?

  • Atrazine exposure disrupts gonadal development in exposed larvae

  • Widespread atrazine contamination was accompanied by observation of hermaphroditic animals in the field


What does all this mean?

  • Atrazine exposure disrupts gonadal development in exposed larvae

  • Widespread atrazine contamination was accompanied by observation of hermaphroditic animals in the field

  • Studies suggest that atrazine impacts amphibians in the wild


What does all this mean?

  • Atrazine exposure disrupts gonadal development in exposed larvae

  • Widespread atrazine contamination was accompanied by observation of hermaphroditic animals in the field

  • Studies suggest that atrazine impacts amphibians in the wild

    • Atrazine contamination of water coincides with amphibian breeding activity


What does this mean to us?


What does this mean to us?

  • Not so much that amphibian population declines (decline is minimal)


What does this mean to us?

  • Not so much that amphibian population declines (decline is minimal)

  • We drink the same water


What does this mean to us?

  • Not so much that amphibian population declines (decline is minimal)

  • We drink the same water

  • Atrazine effects on amphibians vs. atrazine effects on humans


What does this mean to us?

  • Not so much that amphibian population declines (decline is minimal)

  • We drink the same water

  • Atrazine effects on amphibians vs. atrazine effects on humans

  • May cause reproduction problems if long term exposure to atrazine


What does this mean to us?

  • Not so much that amphibian population declines (decline is minimal)

  • We drink the same water

  • Atrazine effects on amphibians vs. atrazine effects on humans

  • May cause reproduction problems if long term exposure to atrazine

  • “Adverse effects on hypothalamic-pituitary function in humans”--Scientific Advisory Panel convened in June 2000


Risk and Exposure


Risk and Exposure


The Bigger Picture


The Bigger Picture

  • Why should we care?


The Bigger Picture

  • Why should we care?

    • Atrazine contamination may affect us also


The Bigger Picture

  • Why should we care?

    • Atrazine contamination may affect us also

    • May not be same effects exhibited in amphibians


The Bigger Picture

  • Why should we care?

    • Atrazine contamination may affect us also

    • May not be same effects exhibited in amphibians

    • More aware of other pesticides


The Bigger Picture

  • Why should we care?

    • Atrazine contamination may affect us also

    • May not be same effects exhibited in amphibians

    • More aware of other pesticides

  • How do we solve Atrazine Contamination?


The Bigger Picture

  • Why should we care?

    • Atrazine contamination may affect us also

    • May not be same effects exhibited in amphibians

    • More aware of other pesticides

  • How do we solve Atrazine Contamination?

    • Prohibit atrazine distribution


The Bigger Picture

  • Why should we care?

    • Atrazine contamination may affect us also

    • May not be same effects exhibited in amphibians

    • More aware of other pesticides

  • How do we solve Atrazine Contamination?

    • Prohibit atrazine distribution

    • Come up with new pesticide


Sources

  • UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON, D.C. 20460 http://www.epa.gov/oppsrrd1/reregistration/atrazine/hed_redchap_16apr02.PDF

  • Atrazine-Induced Hermaphroditism at 0.1 ppb in American Leopard Frogs (Rana pipiens): Laboratory and Field Evidence http://ehp.niehs.nih.gov/members/2003/5932/5932.pdf

  • Feminized Frogs: Herbicide disrupts sexual growth http://www.sciencenews.org/articles/20020420/fob1.asp


ad
  • Login