Liver heat shock proteins (70 and 90), cyp1A1 expression of adult female Catla catla exposed to graded concentration of BPA for 14 days. Gapdh, tbp used as reference control; M, marker; S1, control; S2, 10 μg/I BPA; S3, 100 μg/I BPA; S4, 1000 μg/I BPA.