Interference of pesticides with brain aromatase expression of a native fish (Jenynsia multidentata).

BONANSEA, ROCÍO; GUYÓN, NOELIA; WUNDERLIN, DANIEL ALBERTO; BISTONI, MARÍA DE LOS ANGELES; AMÉ, MARÍA VALERIA

Cracovia

Encuentro; 3rd Young Environmental Scientist Meeting.; 2013

SETAC

Concentrations of Chlorpyrifos and Cypermethrine measured in Suquía river (Córdoba- Argentina) surpassed the international water quality guidelines for pesticides in freshwaters drawing attention on the possible ecological risk. Several indications exist that many natural and synthetic chemicals could interfere with the aromatase CYP19 system and might lead to malfunctioning of the reproductive system, which is the most frequently reported symptom of endocrine disruption in fish. For teleosts fish, two cyp19 genes (cyp19a1 and cyp19a2) have been described. CYP19A1, commonly known as gonadal aromatase, is preferentially expressed in the ovary and plays an important role in sex differentiation and oocyte growth. CYP19A2, called brain aromatase, is constitutively expressed in the brain and is probably involved in the development of the central nervous system, survival, morphology, synaptogenesis, and sex behavior. The aim of the present study was to evaluate changes in cyp19a2 expression in brain of Jenynsia multidentata exposed to environmentally relevant concentrations of pesticides. For this purpose, adult female fishes were exposed over 96 hours to 40ng/L of Cypermethrin and 400ng/L of Chlorpyrifos singly and in technical mixture. Additionally, the same mixture (40ng/L Cypermethrin plus 400ng/L Chlorpyrifos) of a commercial product was tested. The exposure solutions were daily renewed. Total RNA was extracted from brain tissue and nonspecific reverse transcription was performed with Oligo(dT)15 primer. Quantitative polymerase chain reaction was performed using β-actin as housekeeping gen. Our results showed that Chlorpyrifos and the commercial mixture were able to inhibit significantly cyp19a2 expression while Cypermethrin and the technical mixture did not vary from the control. As a result, it could be hypothesized that Chlorpyrifos and its commercial mixture with Cypermethrin could cause or contribute to estrogen-related disorders in J. multidentata. Moreover, the differences observed between the technical and commercial mixtures reinforce the need of further studies at other pesticide concentrations and formulations.