Butachlor causes disruption of HPG and HPT axes in adult female rare minnow (Gobiocypris rarus)

Abstract

a b s t r a c tButachlor is a chloroacetamide herbicide widely used in Asia, and may enter the aquatic environment through agricultural application. In this study, plasma VTG and hormone levels (E2, 11-KT, T3 and T4) were determined after the female rare minnow (Gobiocypris rarus) was exposed to butachlor at environmental relevant concentrations (0, 0.1, 1, and 10 lg/L) for 40 days. The mRNA levels of the HPG axisrelated genes (gnrh, era, vtg, star, lhr, 3b-hsd, cyp11a, cyp17, cyp19a and cyp19b), and the HPT axis-related genes (tra, dio1, dio2, and dio3) were quantified after 20 and 40 days exposure to butachlor. For the HPG axis, the plasma 11-KT was increased at exposure concentration of 10 lg/L, and VTG was significantly decreased at 1 lg/L. Functional genes like gnrh and cyp19b in the brains, star, lhr, cyp11a, 3b-hsd, and cyp19a in the ovaries, and era and vtg in livers were up-regulated. For the HPT axis, the results showed that plasma T4 levels were significantly increased, the gene expression of dio1 was up-regulated, dio2 showed no significant variation, and dio3 was down-regulated in the livers. These results indicated that butachlor may promote the accumulation of T4 in fish through inactive deiodinase type 3. The transcription of HPG axis-related genes could serve as an auto-regulation of hormone levels after exposure to butachlor. Furthermore, the activation of gnrh may play an important role as a feed-back mechanism in the regulation of hormone levels and crosstalk of endocrine axes.

Involvement of thyroid hormone in the intestine and liver development of the common sole (Solea solea L.) larvae

“…Also, in contrast to the current results, administration of goitrogen perchlorate led to increasing of hepatocyte lipid accumulation for zebrafish (Schmidt et al, 2012). In the present work, the higher dose for perchlorate (P100) liver histology showed vacuoles between hepatocytes and degeneration in some cells which can be a signs of stress or hormonal disruption (Zhu et al, 2014).…”

Boule gene expression underpins the meiotic arrest in spermatogenesis in male rainbow trout ( Oncorhynchus mykiss ) exposed to DEHP and butachlor

“…These results are in agreement with other studies on mammalian and non-mammalian vertebrates showing that exposure to DEHP results in meiotic arrest in spermatogenesis and production of fewer spermatozoa (Sharpe et al, 1995;Uren-Webster et al, 2010). However, many works have shown that the adverse effects due to exposure to DEHP and butachlor likely occur preferentially via PPAR signalling pathways by oxidative stress in the testis and oestrogen signalling pathways in the liver (Onorato et al, 2008;Uren-Webster et al, 2010;Zhu et al, 2014).…”

“…LC 50 (96 h) of butachlor in fishes has been reported to range from 0.14 to 0.52 mg/L (0.52 mg/L in rainbow trout, Oncorhynchus mykiss (Tomlin, 1994). Many adverse effects of this herbicide on fish species have been reported (Lasheidani et al, 2008;Guo et al, 2010;Tu et al, 2013;Zhu et al, 2014;Xu et al, 2015).…”

Thyroid hormones and androgens differentially regulate gene expression in testes and ovaries of sexually mature Silurana tropicalis

“…The androgen-mediated decreases in trβ and dio3 expression in ovarian tissue may be indicative of a more feminized profile. For example, exposure to pesticides with known feminizing and TH-related properties have been shown to decrease dio3 transcripts while increasing erα transcripts in various tissues in fish and frogs (butachlor: Zhu et al, 2014;atrazine: Langlois et al, 2010a). In the present study, the expression of erα significantly increased in 5α-DHT and 5β-DHT treated ovary tissues.…”