ATR stimulates expression of gonadal zcyp19A1 encoding aromatase, but not zcypA2 in zebrafish.
Schematic of zCyp19a1 and zCyp19a2 zebrafish promoters with binding sites and start site indicated (arrow) as previously shown by [29]. A. Relative expression of zCyp19a1 and zCyp19a2 transcripts determined by RT-qPCR in juvenile zebrafish (20 dpf) following exposure (72 hrs) to endocrine disruptors including 0.1 μM of 17βE2, 1 μM of genistein (Gen), 10 μM of 4-nonylphenol (4-NP), 10 μM of bisphenol A (Bis A) and 10 μM of atrazine (ATR) beginning at 17dpf. B. Relative expression of zCyp19a1 and zCypA2 transcripts in dissected 20 dpf zebrafish bodies and heads after 72 hrs ATR treatment (10 μM). C. Relative zCyp19a1 and zCyp19a2 transcript levels are shown with ATR stimulation at doses ranging from 0.01 to 10 μM for 72 hrs (left panel), or at different time points (hrs) with 10 μM ATR (right panel). For all panels error bars represent the S.E.M. obtained from analysis of three independent groups of fish (n = 5) using validated primers, with reactions carried out three times each. T-test analysis reveal statistical significance with **p<0.01, *p<0.05.

Chronic exposure to ATR increases the percentage of female zebrafish.
A. The percentage of female zebrafish is shown after chronic exposure to DMSO and increasing ATR concentrations (μM). The number of female fish was assessed visually at three, four (data not shown) and at six months, as shown. Visual inspection for sex-specific landmarks (body shape, body color, fin shape) at both stages suggested an increase in the ratio of female to male fish. Following visual inspection of six month old fish, unambiguous assignment of sex was determined by morphological inspection of gonads. ATR treatment began at 17dpf post-hatching. B. Representative pictures of fish treated with ATR and corresponding gonadal sections stained with hematoxylin and eosin. Oocytes within the perinuclear follicles of the ovary are indicated (black arrowhead), and spermatozoa in the testis are indicated (white arrowhead).