Gonadal development of larval male Xenopus laevis exposed to atrazine in outdoor microcosms

Jooste, A. M.; Du, Preez, L. H.; Carr, J. A.; Giesy, J. P.; Gross, T. S.; Kendall, R. J.; Smith, E. E.; Van Der Kraak, G. L.; Solomon, K. R.

Abstract:

The potential effects of atrazine on gonadal development in metamorphs and subadults of the African clawed frog (Xenopus laevis) were studied under conditions of natural photoperiod and temperatures in outdoor microcosms from August 2002 to June 2003 in South Africa. Triplicate 1100 L microcosms for each nominal concentration of 0.0, 1, 10, and 25 ??g of atrazine/L were used. Measured atrazine concentrations varied <25% throughout the study, and no atrazine was detected in the control microcosms. Tadpoles developed well at all concentrations. On the basis of histological examination of testes of recently metamorphosed stage 66 frogs, 57% of the individuals in the reference group exhibited testicular oocytes as compared with 57, 59, and 39% of the 1, 10, and 25 ??g/L atrazine groups, respectively. The average prevalence of testicular oocytes for all of the treatments including the controls was 54% in a single testis, while, in 35% of individuals, testicular oocytes were observed in both testes. The number of testicular oocytes per individual ranged from 0 to 58 with means of 9.5, 9.8, 8.5, and 11.1 for the 0.0, 1, 10, and 25 ??g of atrazine/L groups, respectively. Ten months after metamorphosis, another subset of juveniles was examined, and the maximum number of testicular oocytes observed was five in one animal. The presence of testicular oocytes was not related to exposure to atrazine and may be a natural phenomenon during ontogeny. ?? 2005 American Chemical Society.

Genre:

Article

ProdID:

70031488

Citation Author:

Jooste, A. M.; Du, Preez, L. H.; Carr, J. A.; Giesy, J. P.; Gross, T. S.; Kendall, R. J.; Smith, E. E.; Van Der Kraak, G. L.; Solomon, K. R.

Citation Contributing Office:

Citation Datum:

Citation Day:

Citation Edition:

Citation Editor:

Citation End Page:

5261

Citation Issue:

Citation Keywords:

Citation Language:

English

Citation Larger Work Title:

Environmental Science and Technology

Citation LatN:

Citation LatS:

Citation LonE:

Citation LonW:

Citation Month:

Citation No Pagination:

Citation Number Of Pages:

Citation Online Only Flag:

Citation Phsyical Description:

Citation Projection:

Citation Public Comments:

Citation Publisher:

Citation Series:

Citation Series Code:

Citation Series Number:

Citation Search Results Text:

Gonadal development of larval male Xenopus laevis exposed to atrazine in outdoor microcosms; 2005; Article; Journal; Environmental Science and Technology; Jooste, A. M.; Du, Preez, L. H.; Carr, J. A.; Giesy, J. P.; Gross, T. S.; Kendall, R. J.; Smith, E. E.; Van Der Kraak, G. L.; Solomon, K. R.