What you

should know

about Atrazine

1. Biography

2. Curriculum Vitae

3. Speaking Schedule

4. Links to Radio

5. Links to Documentaries

6. Links to Videos

7. Other Links

8. Contact Tyrone Hayes


Tyrone Hayes


Tyrone B. Hayes

Department of Integrative Biology, Molecular Toxicology, Group in Endocrinology,

Museum of Vertebrate Zoology, Energy and Resources Group,

University of California at Berkeley

Berkeley, California 94720-3140

(510)643-1054 (off.), (510)643-6264 (fax)

tyrone@berkeley.edu or atrazinelovers@yahoo.com

Personal History


Fellowships, Awards, and Honors

Research Experience and Employment

Other Activities

Reviewer For

Papers (Peer-reviewed)  

1. Hayes, T.B. and P. Licht (1992) Gonadal involvement in size sex dimorphism in the African Bullfrog (Pyxicephalus adspersus). J. Exp. Zool. 264(2): 130‑135.

2. Hayes, T.B., R. Chan, and P. Licht (1993) Interactions of temperature and steroids in larval growth, development, and metamorphosis in a toad (Bufo boreas). J. Exp. Zool. 266(3): 206‑215.

3.  Hayes, T.B. and P. Licht (1993) Metabolism of exogenous steroids by anuran larvae. Gen. Comp. Endocrinol. 91:250‑258.

4. Tsai, P.S., T.B. Hayes, and P. Licht (1993) The role of aromatization in testosterone‑ induced inhibition in female turtles, Trachemys scripta. Biol. Reprod. 50: 144‑151.

5. Hayes, T.B. (1995) Interdependence of corticosterone and thyroid hormones in larval growth and development in the western toad (Bufo boreas). I. Thyroid hormone dependent and independent effects of corticosterone on growth and development. J. Exp. Zool. 271(2): 95-102.

6. Hayes, T.B. and T.-H. Wu (1995) Interdependence of corticosterone and thyroid hormones in larval growth and development in the western toad (Bufo boreas). II. Regulation of corticosterone and thyroid hormones. J. Exp. Zool. 271(2): 103-111.

7. Hayes, T.B. and P. Licht (1995) Factors influencing testosterone metabolism by anuran larvae. J. Exp. Zool. 271(2): 112-119.

8. Hayes, T.B. and T.‑H. Wu (1995) The role of corticosterone in anuran metamorphosis and its potential role in stress‑induced metamorphosis. In Proceedings of the 17th Conference of the European Society of Comparative Endocrinology. Neth. J. Zool. 45(1-2): 107-109.

9. Hayes, T.B. and T.N. Gill (1995) Hormonal regulation of skin gland development in toad larvae (Bufo boreas): The role of the thyroid hormones and corticosterone. Gen. Comp. Endocrinol. 99:161-168.

10. Hayes, T.B. (1995) An histological examination of the effects of corticosterone in larvae of the Western Toad, Bufo boreas (Anura: Bufonidae), and the Oriental Fire‑bellied Toad, Bombina orientalis (Anura: Discoglossidae).  J. Morph. 226:297-307.

11. Hayes, T.B. (1997) Amphibian metamorphosis: An historical perspective. Amer. Zool. 37:121-124.

12. Hayes, T.B. (1997) Steroids as modulators of thyroid hormone activity in amphibian development. Amer. Zool. 37(2):185-195.

13. Hayes, T.B. (1997) Steroid-mimicking environmental contaminants: Their potential role in amphibian declines. pp. 145-150, in: Böhme, W., Bischoff, W. and T. Ziegler (eds.): Herpetologia Bonnensis, Bonn (SEH).

14. Hayes, T.B., T.H. Wu, and T.N. Gill (1997) Similarities in effects of DDT and corticosterone in anuran larvae: Is DDT a stressor or corticosterone mimic? Environ. Toxicol. and Chem. 16(9): 1948-1953.

15. Hayes, T.B. (1997) Hormonal mechanisms as potential constraints on evolution: Examples from the Anura. Amer. Zool. 37: 482-490.

16. 1998 Hayes, T.B. Sex Determination and primary sex differentiation in amphibians. J. Exp. Zool. 281(5): 373-399

17. Hayes, T.B. (1998) Endocrine disruptors in amphibians: Potential impacts and the usefulness of amphibian screens for detecting endocrine disrupting compounds. Science Journal (Kagaku).68: 557-568. (In Japanese).

18. Pearson, A. K., Hayes, T. B. and Licht, P. (1998) Immunochemical identification of thyrotropes and gonadotropes in the pars distalis and pars tuberalis of the toad (Bufo boreas) with reference to ontogenetic changes. Gen. Comp. Endocrinol. 111: 83-94.

19. Hayes, T.B. (1998) Hormonal regulation of sex differentiation in amphibians, reptiles, and birds. In: (E. Knobil and J. D. Neill, eds.)  Encyclopedia of Reproduction. Vol. 4. pp. 102-109. San Diego: Academic Press.

20. Licht, P., T.B. Hayes, P. Tsai, G. Cunha, H. Kim, M. Golbus, S. Hayward, M.C. Martin, R.B. Jaffe, and S.E. Glickman. (1998) Androgens and masculnization of genitalia in the spotted hyaena (Crocuta crocuta). 1. Urogenital morphology and placental androgen production during fetal life. J. Reprod. Fert. 113:105-116.

21. Hayes, T.B. and K.P. Menendez (1999) The effect of sex steroids on primary and secondary sex differentiation in the sexually dichromatic reedfrog (Hyperolius argus: Hyperolidae) from the Arabuko Sokoke Forest of Kenya. Gen. Comp. Endocrinol. 115: 188-199.

22. Hayes, T.B. (1999) Comparative Endocrinology: A tool for understanding mechanisms and predicting effects of endocrine mimicking xenobiotics. IN: L.J. Guillette (ed.). Environmental Endocrine Disruptors: An Evolutionary Perspective. Taylor and Francis. NY.

23. Hayes, T.B. (1999) Endocrine Disruptors and Amphibians. IN: G. Linder, D. Sparling, and C. Bishop. Ecotoxicology in Reptiles and Amphibians. Setac Press. (In Press).

24. Noriega, N. and T. B. Hayes (2000) DDT congener effects on secondary sex coloration in the reed frog Hyperolius argus: A partial evaluation of the Hyperolius argus Estrogen Screen. Comparative Biochemistry and Physiology. Comp. Biochem. Physiol. B. 126B(2): 231-237.

25. Buchholz, D.R. and Hayes, T.B. (2000) Larval period comparison for the spadefoot toads Scaphiopus couchii and Spea multiplicata (Anura: Pelobatidae) Herpetologica. 56(4):455-468.

26. Datuin, J.P., K. Ng, T.B. Hayes, and H. Bern (2001) Effects of glucocorticoids on cartilage growth and response to IGF-I in tilapia (Oreochromis mossambicus). Gen. Comp. Endocrinol. 121 (3): 289-294.

27. Hayes, T.B. (2001) Hyperolius argus endocrine screen test. Official Gazette of the United States Patent and Trademark Office Patents.Sep. 26, 2000. 1238(4): No Pagination. US 6123918; September 26, 2000, 424-92, USA.

28. Buchholz, D.R, and T.B. Hayes (2002) Evolutionary patterns of diversity in spadefoot toad metamorphosis (anura: Pelobatidae). Copeia. 2002(1):180-189.

29. Hayes, T.B., A. Collins, M. Lee, M. Mendoza, N. Noriega, A.A. Stuart, and A. Vonk (2002)  Hermaphroditic, demasculinized frogs following exposure to the herbicide, atrazine, at ecologically relevant doses. Proc. Nat. Acad. Sciences (USA).  99(8): 5476-5480.

30. Hayes,  T.B, K. Haston, M. Tsui, A. Hoang, C. Haeffele, and A. Vonk (2002) Hermaphrodites beyond the corn field: Atrazine-induced testicular oogenesis in leopard frogs (Rana pipiens). Nature 419: 895-896.

31. Hayes, T.B, K. Haston, M. Tsui, A. Hoang, C. Haeffele, and A. Vonk (2003) Atrazine-induced hermaphroditism at 0.1 ppb in American leopard frogs: Evidence from the laboratory and the wild. Environ. Health. Perspect. 111(4): 1-8.

32. Hayes, T.B. (2004) There is no denying this: Defusing the confusion about atrazine. Bioscience. 54(12): 1138-1149.

33. Hayes, T.B. (2005) Welcome to the revolution: Integrative Biology and assessing the impact of endocrine disruptors on environmental and public health. J. Integrative and Comp. Biol. 45: 321-329.

34. Buchholz, D.R. and T.B. Hayes (2005) Variation in thyroid hormone action and content underlies species differences in the timing of metamorphosis in desert frogs. Evolution and Development. 7(5): 458-467.

35. Hayes, T.B. (2005) Comment on “Gonadal development of larval male Xenopus laevis exposed to atrazine in outdoor microcosms”. Environ. Sci. Tech. In press.

36. Hayes T., A. Stuart, G. Mendoza, A. Collins, N. Noriega, A. Vonk, G. Johnston, R. Liu, and D. Kpodzo (2005) Characterization of atrazine-induced gonadal malformations and effects of an androgen antagonist (cyproterone acetate) and exogenous estrogen (estradiol 17b): Support for the demasculinization/feminization hypothesis. Environ. Health Perspect. 114 (Suppl. 1), 134-141.

37. Hayes, T.B, P. Case, S. Chui, D. Chung, C. Haefele, K. Haston, M. Lee, V.-P. Mai, Y. Marjuoa Y, J. Parker, and M. Tsui (2005) Pesticide mixtures, endocrine disruption, and amphibian declines: Are we underestimating the impact? Environ. Health Perspect. 114 (Suppl. 1), 40-50.

38. Hayes, T.B. It ain’t that simple. Environ. Health Perspect. In Press.

39. Fan W, Yanase T, Morinaga H, Gondo S, Okabe T, Nomura M, Komatsu T, Morohashi KI, Hayes TB, Takayanagi R, Nawata H. 2007. Atrazine-Induced Aromatase Expression is SF-1- Dependent: Implications for Endocrine Disruption in Wildlife and Reproductive Cancers in Humans Environ Health Perspect: doi:10.1289/ehp.9758. [Online 5 February 2007]

More than 150 abstracts and more than 350 invited talks and symposia.


Curriculum Vitae

1. What is Atrazine?

2. Environmental Contamination

3. Ecological Impacts

4. Endocrine Disruption

5. Neural Damage

6. Pregnancy Loss

7. Reproductive Cancers

8. Endangered Species

9. Risks and Benefits