Response of the amphibian tadpole Xenopus laevis to atrazine during sexual differentiation of the ovary.
Xenopus laevis tadpoles (stage 56) were exposed to 21 microg/L atrazine under laboratory-controlled conditions in a static system. Following a 48-h exposure period at 21+/-0.5 degrees C during sexual differentiation, tadpoles were fixed, and the kidney-gonad complex was microdissected. Quantitative histological analysis revealed in atrazine-exposed ovaries a significant (p < 0.05) increase in frequency of secondary oogonia. Atresia, or oogonial resorption of both primary and secondary oogonia, also increased significantly (p < 0.05). The results suggest that these primary germ cells, which constitute the total number of germ cells in the ovary for the reproductive life of the organism, were reduced by 20% following a 48-h exposure period compared to 2% in controls.
Tavera-Mendoza
Luz
L
Department of Biology, Concordia University, Montreal, Quebec, Canada.
Ruby
Sylvia
S
Brousseau
Pauline
P
Fournier
Michel
M
Cyr
Daniel
D
Marcogliese
David
D
D000818:Animals; D001280:Atrazine / Q000009:adverse effects*; D004781:Environmental Exposure; D005260:Female; D006540:Herbicides / Q000009:adverse effects*; D007814:Larva; D008297:Male; D010053:Ovary / Q000187:drug effects* / Q000254:growth & development; D012733:Sex Differentiation / Q000187:drug effects*; D014874:Water Pollutants, Chemical / Q000009:adverse effects*; D014982:Xenopus laevis / Q000254:growth & development*
D006540:Herbicides; D014874:Water Pollutants, Chemical; D001280:Atrazine