Gonadal Development of Larval Male <i>Xenopus laevis</i> Exposed to Atrazine in Outdoor Microcosms

Jooste, Alarik M.; Preez, Louis H. Du; Carr, James A.; Giesy, John P.; Gross, Timothy S.; Kendall, Ronald J.; Smith, Ernest E.; Kraak, Glen L. Van Der; Solomon, Keith R.

doi:10.1021/es048134q

Cited by 66 publications

(41 citation statements)

References 24 publications

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“…The presence of testicular oocytes as a natural phenomenon during ontogeny, and a decrease in their frequency as the fish matures, agrees with studies on gonadal development in African clawed frogs Xenopus laevis exposed to atrazine under outdoor microcosm conditions (Jooste et al 2005). The authors report a 39 to 59% prevalence of intersex in recently metamorphosed frogs, independently of whether frogs were exposed to an EDC or not.…”

Section: Discussionsupporting

confidence: 84%

Macroscopic gonadal deviations and intersex in developing whitefish Coregonus lavaretus

Bernet

Wahli²,

Kipfer³

et al. 2009

Aquat. Biol.

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In Lake Thun, Switzerland, a significant number of whitefish Coregonus lavaretus were found to exhibit abnormal gonadal morphology. To determine the time at which the morphological deviations from a normal gonadal arrangement develop, we conducted experiments designed to: (1) examine whether the morphologic gonadal variations develop during or after gonadal differentiation, and (2) characterise the entire ontogenetic gonadal development in whitefish from hatching until maturity. For these experiments, whitefish were reared under controlled conditions with distinct water sources and temperature regimes (Lake Thun water: 4 to 22°C; spring water: 8 to 9°C). Gonadal development in the spring water group was clearly delayed with respect to age, but similar to the Lake Thun water group with respect to degree-days in Celsius (°D). Undifferentiated gonads were first seen at 65 d post-hatch and 491°D. Ovarian differentiation (starting from 1734 to 1820°D) preceded testicular differentiation (starting from 1989 to 3673°D). The first fish with mature germ cells were recognised at 8163 to 8356°D. Morphological gonadal deviations became evident during gonadal differentiation. Constrictions and asymmetries developed for the first time in the first (0+) or second (1+) year-of-life, at a body length of 13 to 18 cm. Aplasia and compartmentation were recorded in the third (2+) year-of-life at a body length of 16 to 18 cm. Intersex fish occurred at a frequency of 8 to 9% during gonadal sex differentiation. Because no evidence for the presence of exogenic endocrine active substances was revealed, we suppose that there is a naturally increased mosaic intersex condition in whitefish during the ontogenetic gonadal differentiation process.

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Section: Discussionsupporting

confidence: 84%

Macroscopic gonadal deviations and intersex in developing whitefish Coregonus lavaretus

Bernet

Wahli²,

Kipfer³

et al. 2009

Aquat. Biol.

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“…The sample for the non-DDT-sprayed area consisted of one X. muelleri and three X. laevis from three different sites. Preparation of the histology slides was adapted from Weldon (2005) and Jooste et al (2005). Serial sections were made longitudinally at 6 µm intervals and then stretched and affixed to microscope slides using Mayer"s albumen and a heating plate (45 ⁰C).…”

Section: Histological Preparationsmentioning

confidence: 99%

DDT exposure of frogs: A case study from Limpopo Province, South Africa

2016

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Highlights Contaminants is suspected to play a part in amphibian declines worldwide  No POPs data in frogs from areas where DDT is used for malaria control  Quantifiable DDT was found in frog fat from an area where DDT is used  No testicular oocytes were found in any frog  Significant asymmetric testicular morphology in frogs from the sprayed area AbstractAmphibians are globally under pressure with environmental contaminants contributing to this. Despite caution aired more than 80 years ago of threats posed to amphibians by DDT spraying for disease vector control, no data have been published on concentrations or effects of DDT contamination in frogs from areas where DDT is actively sprayed to control the insect vectors of malaria. In this study, we sampled fat bodies of Xenopus laevis and X. muelleri naturally occurring in an area where indoor residual spraying of DDT is employed and from adjacent, non-sprayed, areas. ΣDDT concentrations ranged between

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“…These effects possibly affect results of ecotoxicological study. In fact, studies involving some problems have contrary results from different laboratories [45,59,67,68] . It is suggested that quality control of X. laevis like other model animals in ecotoxicological study is very important for the scientificity of experi- mental results.…”

Section: Foodmentioning

confidence: 96%

“…These two reports exploded a drastic debate from relating scholars and US EPA. So far, there is open whether atrazine can disrupt the endocrine system of X. laevis because of obvious inconsistence from different laboratories [51,58,59] . Fort Environmental Laboratory of US is devoted to the development and application of FETAX for long period, and has valuated developmental toxicology of many environmental pollutants and environmental samples [60][61][62] .…”

Section: Available Information On Biology Of X Laevis For Ecotoxicolmentioning

confidence: 99%

Application of Xenopus laevis in ecotoxicology (I) —Introduction and quality control of laboratory animal

Qin

2006

CHINESE SCI BULL

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The aim of the series of papers is to discuss the application of Xenopus laevis, as model animal in biology, in ecotoxicology. X. laevis as model animal is wildly used in biological study and has provided a lot of relating data because of many advantages, such as living in water and being easily maintained, laying eggs in the whole year, and externally fertilizing and developing. Embryos and larvae of X. laevis like other amphibians are directly exposed in the aquatic environment and sensitive to pollutants. In addition, sex differentiation and sex organ development of X. laevis are sensitive to sex hormones and endocrine disruptors with sex hormone activities, which enable X. laevis to be used in studies on sex hormone disruption and reproductive toxicity of endocrine disruptors. Metamorphic development of X. laevis is very sensitive to thyroid hormones and thyroid disruptors, which enables X. laevis to be used for evaluating thyroid disruptors. Also, X. laevis ecotoxicology can be linked with amphibian population declines and malformed frog occurrence, being one of the hotspots in ecology. Thus, more and more laboratories have introduced X. laevis to ecotoxicological study. The quality of laboratory animals correlates with scientificity and reliability of results from animal experiments. It is especially important for toxicology. Quality control of X. laevis involving several factors such as water and food is discussed in this paper.

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Gonadal Development of Larval Male Xenopus laevis Exposed to Atrazine in Outdoor Microcosms

Cited by 66 publications

References 24 publications

Macroscopic gonadal deviations and intersex in developing whitefish Coregonus lavaretus

Macroscopic gonadal deviations and intersex in developing whitefish Coregonus lavaretus

DDT exposure of frogs: A case study from Limpopo Province, South Africa

Application of Xenopus laevis in ecotoxicology (I) —Introduction and quality control of laboratory animal

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