Thursday, March 4, 2010

Today's science, "In the News," talks about the, "Gender Continuum," and "Involuntary Castration."

The unity and diversity of life is an important basic concept on which to reflect when reading an article such as this one on the pesticide, "atrazine," and its effects on frogs. For the, "unity," part...DNA in frogs and DNA in humans is still DNA. For the, "diversity," part, you don't look like a frog, do you? With the concepts of unity and diversity in mind, think about atrazine and other chemicals (like those found in some plastics) that interact with endocrine systems of organisms.

While banned in the European Union,...
atrazine is one of the
most widely used herbicides in the U.S.
with 77 million
lb applied in 2003.
Source: Lee, J. Popular pesticide faulted for frogs' sexual abnormalities New York Times as cited by:; Accessed 3-4-2010.

Note that: is the link from today's, "Science in the News." (Remember, the, Science in the News," box (below and in left-hand column) changes each day so I post the link, too. At a future date, the box will not match the link.)
Herbicide Turns Male Frogs Female A common weed killer known as atrazine causes chemical castration in frogs and can even turn some into females. Researchers found that long-term exposure to low levels of atrazine emasculated three-quarters of male laboratory frogs, while ninety percent of the study subjects exhibited low testosterone levels, decreased breeding gland size, feminized laryngeal development, suppressed mating behavior, reduced sperm production, and decreased fertility. Furthermore, the remaining 10 percent actually turned into females that were able to copulate with males and produce eggs. Because the parents were both genetically male, all the larvae produced by those eggs were also male. More ... Discuss

Why did I say, "The unity and diversity of life is an important basic concept on which to reflect when reading an article such as this one on the pesticide, "atrazine," and its effects on frogs?"

For the, "unity," part...DNA in frogs and DNA in humans is still DNA. Well, despite the, "diversity," part, similar DNA means many biochemical processes, including those of the endocrine system(s), are also similar. What does this similarity mean about public policy suggestions and laws when it comes to atrazine and other chemicals (like those found in some plastics) that interact with endocrine systems of organisms? What do you think?

Dogs on golf fields, turtles, now frogs...humans? Reflect. Use Reach ReadingTM to get into the technical literature on this topic.

This topic of changing gender can be confusing to children. After all, it is for adults, so, caution is advised in presenting this to young people if you elect to do so. The blog is for adults though and is on science literacy. Adults can stretch and reflect and stretch some more. And we need to in order to interact with our governments well about technical and scientific issues. We need to know things about the effects of chemicals found in pesticides and plastics.

So let's go to the original sources, the laboratory report(s) found in refereed journal articles.

… , demasculinized frogs after exposure to the herbicide atrazine at low ecologically … TB Hayes, A Collins, M Lee, M … - Proceedings of the …, 2002 - National Acad Sciences This and the extra reading articles listed below are among many found on a Google search on 3-4-2010)

Want to read more on this topic? Here are some of the many journal articles relating to atrazine:

  • T. B. Hayes, P. Falso, S. Gallipeau, and M. Stice. 2010. The cause of global amphibian declines: a developmental endocrinologist''s perspectiveJ. Exp. Biol. 213:921-933 Abstract
  • B. C. Iker, P. Kambesis, S. A. Oehrle, C. Groves, and H. A. Barton. 2010. Microbial Atrazine Breakdown in a Karst Groundwater System and Its Effect on Ecosystem EnergeticsJ. Environ. Qual. 39:509-518 Abstract
  • M. Solari, J. Paquin, P. Ducharme, and M. Boily. 2010. P19 Neuronal Differentiation and Retinoic Acid Metabolism as Criteria to Investigate Atrazine, Nitrite, and Nitrate Developmental ToxicityToxicol Sci 113:116-126 Abstract
  • M. A. Altieri. 2009. The Ecological Impacts of Large-Scale Agrofuel Monoculture Production Systems in the AmericasBulletin of Science Technology Society 29:236-244 Abstract
  • C. Scott, C. J. Jackson, C. W. Coppin, R. G. Mourant, M. E. Hilton, T. D. Sutherland, R. J. Russell, and J. G. Oakeshott.2009. Catalytic Improvement and Evolution of Atrazine ChlorohydrolaseAppl. Environ. Microbiol. 75:2184-2191 Abstract
  • W. Kloas, I. Lutz, T. Springer, H. Krueger, J. Wolf, L. Holden, and A. Hosmer. 2009. Does Atrazine Influence Larval Development and Sexual Differentiation in Xenopus laevis?Toxicol Sci 107:376-384 Abstract
  • P. R. Ehrlich and R. M. Pringle. 2008. Colloquium Paper: Where does biodiversity go from here? A grim business-as-usual forecast and a hopeful portfolio of partial solutions. Proc. Natl. Acad. Sci. USA 105:11579-11586 Abstract
  • D. B. Wake and V. T. Vredenburg. 2008. Colloquium Paper: Are we in the midst of the sixth mass extinction? A view from the world of amphibians. Proc. Natl. Acad. Sci. USA 105:11466-11473 Abstract
  • A. Chandra and D. R. Huff. 2008. Salmacisia, a new genus of Tilletiales: reclassification of Tilletia buchloeana causing induced hermaphroditism in buffalograss. Mycologia 100:81-93 Abstract
  • A. Hamdoun and D. Epel. 2007. Embryo stability and vulnerability in an always changing world. Proc. Natl. Acad. Sci. US.A 104:1745-1750 Abstract
  • J. T. Sanderson. 2006. The Steroid Hormone Biosynthesis Pathway as a Target for Endocrine-Disrupting ChemicalsToxicol Sci 94:3-21 Abstract
  • S. Matsushita, J. Yamashita, T. Iwasawa, T. Tomita, and M. Ikeda. 2006. Effects of in ovo exposure to imazalil and atrazine on sexual differentiation in chick gonads. Poult. Sci. 85:1641-1647 Abstract
  • G. Giusi, R. M. Facciolo, M. Canonaco, E. Alleva, V. Belloni, F. Dessi'-Fulgheri, and D. Santucci. 2006. The Endocrine Disruptor Atrazine Accounts for a Dimorphic Somatostatinergic Neuronal Expression Pattern in MiceToxicol Sci. 89:257-264 Abstract
  • K. Wenger, L. Bigler, M. J.-F. Suter, R. Schonenberger, S. K. Gupta, and R. Schulin. 2005. Effect of Corn Root Exudates on the Degradation of Atrazine and Its Chlorinated Metabolites in SoilsJ. Environ. Qual. 34:2187-2196 Abstract
  • M. Hecker, J.-W. Park, M. B. Murphy, P. D. Jones, K. R. Solomon, G. Van Der Kraak, J. A. Carr, E. E. Smith, L. du Preez, R. J. Kendall, and J. P. Giesy. 2005. Effects of Atrazine on CYP19 Gene Expression and Aromatase Activity in Testes and on Plasma Sex Steroid Concentrations of Male African Clawed Frogs (Xenopus laevis)Toxicol Sci. 86:273-280 Abstract
  • K. W. Wilhelms, S. A. Cutler, J. A. Proudman, L. L. Anderson, and C. G. Scanes. 2005. Atrazine and the Hypothalamo-Pituitary-Gonadal Axis in Sexually Maturing Precocial Birds: Studies in Male Japanese QuailToxicol Sci. 86:152-160 Abstract
  • R. L. Melnick. A Daubert. 2005. Motion: A Legal Strategy to Exclude Essential Scientific Evidence in Toxic Tort Litigation. AJPH 95:S30-S34 Abstract
  • T. B. Hayes. 2005. Welcome to the Revolution: Integrative Biology and Assessing the Impact of Endocrine Disruptors on Environmental and Public Health. Integr. Comp. Biol. 45:321-329 Abstract
  • D. J. Fort, J. H. Thomas, R. L. Rogers, A. Noll, C. D. Spaulding, P. D. Guiney, and J. A. Weeks. 2004. Evaluation of the Developmental and Reproductive Toxicity of Methoxychlor using an Anuran (Xenopus tropicalis) Chronic Exposure ModelToxicol Sci 81:443-453 Abstract
  • D. J. Fort, P. D. Guiney, J. A. Weeks, J. H. Thomas, R. L. Rogers, A. M. Noll, and C. D. Spaulding. 2004. Effect of Methoxychlor on Various Life Stages of Xenopus laevis. Toxicol Sci 81:454-466 Abstract
  • K. Hilscherova, P. D. Jones, T. Gracia, J. L. Newsted, X. Zhang, J. T. Sanderson, R. M. K. Yu, R. S. S. Wu, and J. P. Giesy. 2004. Assessment of the Effects of Chemicals on the Expression of Ten Steroidogenic Genes in the H295R Cell Line Using Real-Time PCR Toxicol Sci. 81:78-89 Abstract
  • E. L. Abel, S. M. Opp, C. L. M. J. Verlinde, T. K. Bammler, and D. L. Eaton. 2004. Characterization of Atrazine Biotransformation by Human and Murine Glutathione S-Transferases. Toxicol Sci. 80:230-238 Abstract
  • I. Rot-Nikcevic and R. J. Wassersug. 2004. Arrested development in Xenopus laevis tadpoles: how size constrains metamorphosis. J. Exp. Biol. 207:2133-2145 Abstract
  • V. Garcia-Gonzalez, F. Govantes, L. J. Shaw, R. G. Burns, and E. Santero. 2003. Nitrogen Control of Atrazine Utilization in Pseudomonas sp. Strain ADP. Appl. Environ. Microbiol. 69:6987-6993 Abstract
  • J. M. Kiesecker. 2002. From the Cover: Synergism between trematode infection and pesticide exposure: A link to amphibian limb deformities in nature? Proc. Natl. Acad. Sci. USA 99:9900-9904 Abstract


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