Effects of the herbicide pendimethalin on hormone receptor expressions and dorsal fin biometrics in Thai medaka, Oryzias minutillus (Actinopterygii: Beloniformes: Adrianichthyidae)

Background. Xeno-oestrogens have negative effects on the endocrine systems of wildlife including freshwater fish.  Pendimethalin is a herbicide found in the environment which exerts some oestrogenic action in vivo. Dwarf medaka (known also as Thai medaka), Oryzias minutillus Smith, 1945...

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Main Authors: A. Ngamniyom, B. Panyarachun
Format: Article
Language:English
Published: Pensoft Publishers 2012-09-01
Series:Acta Ichthyologica et Piscatoria
Subjects:
Online Access:https://aiep.pensoft.net/article/26318/download/pdf/
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author A. Ngamniyom
B. Panyarachun
author_facet A. Ngamniyom
B. Panyarachun
author_sort A. Ngamniyom
collection DOAJ
description Background. Xeno-oestrogens have negative effects on the endocrine systems of wildlife including freshwater fish.  Pendimethalin is a herbicide found in the environment which exerts some oestrogenic action in vivo. Dwarf medaka (known also as Thai medaka), Oryzias minutillus Smith, 1945, inhabit the natural aquatic environments.  Dorsal fin of this species is a secondary sex character controlled by sex hormones and assumes as a sensitive bioindicator for testing of oestrogenic chemicals.  In this study, we aimed to examine the pendimethalin effects on hormone receptor expressions and dorsal fin biometrics in adult Thai medaka. Materials and methods. Pendimethalin effects on the androgen receptor (AR) and estrogen receptor (ER) β expressions in dorsal fins were determined by semi-quantitative RT-PCR.  The fin biometry was presented as the values (%) of the dorsal fin length (DFL) divided by the standard length (SL). Results. In males, AR levels decreased when the fish were exposed to 0.1 µg · mL–1 pendimethalin for 60 days and were exposed to 1 µg · mL–1 for 30 and 60 days.  In females, a 60-day treatment with 1 µg · mL–1 caused AR levels to decrease.  Conversely, in males, ERβ levels increased after 30 and 60 days of treatment with 1 µg · mL–1.  In females, ERβ levels increased after 30 days of treatment with 1 µg · mL–1 and 60 days of treatment with 0.1 µg · mL–1.  In males, values of DFL/SL% decreased after exposure to 1 µg · mL–1 for 60 days.  Additionally, we observed 4 testis-ova among 30 gonads from males treated with 1 µg · mL–1 for 60 days. Conclusion. Our results suggest that pendimethalin may interfere with endocrine processes via hormone receptors, leading to the feminisation of dorsal fins and gonads in Thai medaka
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spelling doaj.art-a578effefb3f4095a752db185c285a2d2022-12-22T03:28:42ZengPensoft PublishersActa Ichthyologica et Piscatoria1734-15152012-09-0142323924610.3750/AIP2011.42.3.0826318Effects of the herbicide pendimethalin on hormone receptor expressions and dorsal fin biometrics in Thai medaka, Oryzias minutillus (Actinopterygii: Beloniformes: Adrianichthyidae)A. NgamniyomB. PanyarachunBackground. Xeno-oestrogens have negative effects on the endocrine systems of wildlife including freshwater fish.  Pendimethalin is a herbicide found in the environment which exerts some oestrogenic action in vivo. Dwarf medaka (known also as Thai medaka), Oryzias minutillus Smith, 1945, inhabit the natural aquatic environments.  Dorsal fin of this species is a secondary sex character controlled by sex hormones and assumes as a sensitive bioindicator for testing of oestrogenic chemicals.  In this study, we aimed to examine the pendimethalin effects on hormone receptor expressions and dorsal fin biometrics in adult Thai medaka. Materials and methods. Pendimethalin effects on the androgen receptor (AR) and estrogen receptor (ER) β expressions in dorsal fins were determined by semi-quantitative RT-PCR.  The fin biometry was presented as the values (%) of the dorsal fin length (DFL) divided by the standard length (SL). Results. In males, AR levels decreased when the fish were exposed to 0.1 µg · mL–1 pendimethalin for 60 days and were exposed to 1 µg · mL–1 for 30 and 60 days.  In females, a 60-day treatment with 1 µg · mL–1 caused AR levels to decrease.  Conversely, in males, ERβ levels increased after 30 and 60 days of treatment with 1 µg · mL–1.  In females, ERβ levels increased after 30 days of treatment with 1 µg · mL–1 and 60 days of treatment with 0.1 µg · mL–1.  In males, values of DFL/SL% decreased after exposure to 1 µg · mL–1 for 60 days.  Additionally, we observed 4 testis-ova among 30 gonads from males treated with 1 µg · mL–1 for 60 days. Conclusion. Our results suggest that pendimethalin may interfere with endocrine processes via hormone receptors, leading to the feminisation of dorsal fins and gonads in Thai medakahttps://aiep.pensoft.net/article/26318/download/pdf/pendimethalinandrogen receptoroestrogen recept
spellingShingle A. Ngamniyom
B. Panyarachun
Effects of the herbicide pendimethalin on hormone receptor expressions and dorsal fin biometrics in Thai medaka, Oryzias minutillus (Actinopterygii: Beloniformes: Adrianichthyidae)
Acta Ichthyologica et Piscatoria
pendimethalin
androgen receptor
oestrogen recept
title Effects of the herbicide pendimethalin on hormone receptor expressions and dorsal fin biometrics in Thai medaka, Oryzias minutillus (Actinopterygii: Beloniformes: Adrianichthyidae)
title_full Effects of the herbicide pendimethalin on hormone receptor expressions and dorsal fin biometrics in Thai medaka, Oryzias minutillus (Actinopterygii: Beloniformes: Adrianichthyidae)
title_fullStr Effects of the herbicide pendimethalin on hormone receptor expressions and dorsal fin biometrics in Thai medaka, Oryzias minutillus (Actinopterygii: Beloniformes: Adrianichthyidae)
title_full_unstemmed Effects of the herbicide pendimethalin on hormone receptor expressions and dorsal fin biometrics in Thai medaka, Oryzias minutillus (Actinopterygii: Beloniformes: Adrianichthyidae)
title_short Effects of the herbicide pendimethalin on hormone receptor expressions and dorsal fin biometrics in Thai medaka, Oryzias minutillus (Actinopterygii: Beloniformes: Adrianichthyidae)
title_sort effects of the herbicide pendimethalin on hormone receptor expressions and dorsal fin biometrics in thai medaka oryzias minutillus actinopterygii beloniformes adrianichthyidae
topic pendimethalin
androgen receptor
oestrogen recept
url https://aiep.pensoft.net/article/26318/download/pdf/
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AT bpanyarachun effectsoftheherbicidependimethalinonhormonereceptorexpressionsanddorsalfinbiometricsinthaimedakaoryziasminutillusactinopterygiibeloniformesadrianichthyidae