Effects of 17β-trenbolone on Eastern and Western mosquitofish (Gambusia holbrooki and G. affinis) anal fin growth and gene expression patterns

Erica K. Brockmeier, Yukiko Ogino, Taisen Iguchi, David S. Barber, Nancy D. Denslow

Research output: Contribution to journalArticle

23 Citations (Scopus)

Abstract

The Eastern and Western mosquitofish (Gambusia holbrooki and G. affinis) are potential bioindicator organisms for endocrine disruptors. Male mosquitofish have an elongated anal fin (gonopodium) used for internal fertilization whose formation is driven by androgens. Normal female mosquitofish have a normal, rounded anal fin which undergoes elongation into a gonopodium structure when female mosquitofish are exposed to androgenic chemicals. Significant issues with using mosquitofish as a bioindicator include the lack of knowledge on how anal fin growth in females corresponds to endpoints relevant to biological integrity and the lack of information on the molecular pathways that regulate anal fin growth. The objectives of this study were to understand how androgen-induced anal fin elongation relates to changes in endpoints related to the female reproductive system and to understand how anal fin elongation occurs in androgen-exposed female mosquitofish. To achieve these objectives, adult female G. holbrooki were exposed to a vehicle control or one of three doses of the androgen 17β-trenbolone (TB) at nominal concentrations of 0.1, 1 or 10 μg TB/L. Anal fin measurements were taken and livers were used for quantitative polymerase chain reaction analysis of vitellogenin (vtg) mRNA expression at multiple time points. 10 μg TB/L induced anal fin elongation after 7 days of treatment (one-way ANOVA, p< 0.05) as did 0.1 and 1 μg TB/L at later time points (one-way ANOVA, p< 0.05). 10 μg TB/L significantly reduced hepatic vtg gene expression at all time points assessed (one-way ANOVA, p< 0.05). There was no correlation between anal fin elongation levels and vtg gene expression (Spearman's ρ, p> 0.05). In a separate experiment, female G. holbrooki and G. affinis were exposed to the vehicle control or 1 μg TB/L. Anal fins were used for qualitative gene expression analysis of the genes sonic hedgehog (shh), muscle segment homeobox C (msxC), and fibroblast growth factor receptor 1 (fgfr1) by in situ hybridization. Shh was expressed in the distal tip of the gonopodium while msxC and fgfr1 were more widely expressed along the same anal fin rays during androgen exposure. These data provide insight into the molecular pathways involved in anal fin elongation and pave the way for future work toward developing the mosquitofish into a bioindicator organism for endocrine disruptors.

Original languageEnglish
Pages (from-to)163-170
Number of pages8
JournalAquatic Toxicology
Volume128-129
DOIs
Publication statusPublished - Mar 5 2013
Externally publishedYes

Fingerprint

Trenbolone Acetate
Cyprinodontiformes
trenbolone
Gambusia holbrooki
Gambusia affinis
fins
gene expression
androgen
Gambusia
Gene Expression
Androgens
Growth
androgens
bioindicator
Receptor, Fibroblast Growth Factor, Type 1
Endocrine Disruptors
endocrine disruptor
Homeobox Genes
muscle
endocrine-disrupting chemicals

All Science Journal Classification (ASJC) codes

  • Aquatic Science
  • Health, Toxicology and Mutagenesis

Cite this

Effects of 17β-trenbolone on Eastern and Western mosquitofish (Gambusia holbrooki and G. affinis) anal fin growth and gene expression patterns. / Brockmeier, Erica K.; Ogino, Yukiko; Iguchi, Taisen; Barber, David S.; Denslow, Nancy D.

In: Aquatic Toxicology, Vol. 128-129, 05.03.2013, p. 163-170.

Research output: Contribution to journalArticle

Brockmeier, Erica K. ; Ogino, Yukiko ; Iguchi, Taisen ; Barber, David S. ; Denslow, Nancy D. / Effects of 17β-trenbolone on Eastern and Western mosquitofish (Gambusia holbrooki and G. affinis) anal fin growth and gene expression patterns. In: Aquatic Toxicology. 2013 ; Vol. 128-129. pp. 163-170.
@article{bf83438648f4476285c35800a7925959,
title = "Effects of 17β-trenbolone on Eastern and Western mosquitofish (Gambusia holbrooki and G. affinis) anal fin growth and gene expression patterns",
abstract = "The Eastern and Western mosquitofish (Gambusia holbrooki and G. affinis) are potential bioindicator organisms for endocrine disruptors. Male mosquitofish have an elongated anal fin (gonopodium) used for internal fertilization whose formation is driven by androgens. Normal female mosquitofish have a normal, rounded anal fin which undergoes elongation into a gonopodium structure when female mosquitofish are exposed to androgenic chemicals. Significant issues with using mosquitofish as a bioindicator include the lack of knowledge on how anal fin growth in females corresponds to endpoints relevant to biological integrity and the lack of information on the molecular pathways that regulate anal fin growth. The objectives of this study were to understand how androgen-induced anal fin elongation relates to changes in endpoints related to the female reproductive system and to understand how anal fin elongation occurs in androgen-exposed female mosquitofish. To achieve these objectives, adult female G. holbrooki were exposed to a vehicle control or one of three doses of the androgen 17β-trenbolone (TB) at nominal concentrations of 0.1, 1 or 10 μg TB/L. Anal fin measurements were taken and livers were used for quantitative polymerase chain reaction analysis of vitellogenin (vtg) mRNA expression at multiple time points. 10 μg TB/L induced anal fin elongation after 7 days of treatment (one-way ANOVA, p< 0.05) as did 0.1 and 1 μg TB/L at later time points (one-way ANOVA, p< 0.05). 10 μg TB/L significantly reduced hepatic vtg gene expression at all time points assessed (one-way ANOVA, p< 0.05). There was no correlation between anal fin elongation levels and vtg gene expression (Spearman's ρ, p> 0.05). In a separate experiment, female G. holbrooki and G. affinis were exposed to the vehicle control or 1 μg TB/L. Anal fins were used for qualitative gene expression analysis of the genes sonic hedgehog (shh), muscle segment homeobox C (msxC), and fibroblast growth factor receptor 1 (fgfr1) by in situ hybridization. Shh was expressed in the distal tip of the gonopodium while msxC and fgfr1 were more widely expressed along the same anal fin rays during androgen exposure. These data provide insight into the molecular pathways involved in anal fin elongation and pave the way for future work toward developing the mosquitofish into a bioindicator organism for endocrine disruptors.",
author = "Brockmeier, {Erica K.} and Yukiko Ogino and Taisen Iguchi and Barber, {David S.} and Denslow, {Nancy D.}",
year = "2013",
month = "3",
day = "5",
doi = "10.1016/j.aquatox.2012.12.007",
language = "English",
volume = "128-129",
pages = "163--170",
journal = "Aquatic Toxicology",
issn = "0166-445X",
publisher = "Elsevier",

}

TY - JOUR

T1 - Effects of 17β-trenbolone on Eastern and Western mosquitofish (Gambusia holbrooki and G. affinis) anal fin growth and gene expression patterns

AU - Brockmeier, Erica K.

AU - Ogino, Yukiko

AU - Iguchi, Taisen

AU - Barber, David S.

AU - Denslow, Nancy D.

PY - 2013/3/5

Y1 - 2013/3/5

N2 - The Eastern and Western mosquitofish (Gambusia holbrooki and G. affinis) are potential bioindicator organisms for endocrine disruptors. Male mosquitofish have an elongated anal fin (gonopodium) used for internal fertilization whose formation is driven by androgens. Normal female mosquitofish have a normal, rounded anal fin which undergoes elongation into a gonopodium structure when female mosquitofish are exposed to androgenic chemicals. Significant issues with using mosquitofish as a bioindicator include the lack of knowledge on how anal fin growth in females corresponds to endpoints relevant to biological integrity and the lack of information on the molecular pathways that regulate anal fin growth. The objectives of this study were to understand how androgen-induced anal fin elongation relates to changes in endpoints related to the female reproductive system and to understand how anal fin elongation occurs in androgen-exposed female mosquitofish. To achieve these objectives, adult female G. holbrooki were exposed to a vehicle control or one of three doses of the androgen 17β-trenbolone (TB) at nominal concentrations of 0.1, 1 or 10 μg TB/L. Anal fin measurements were taken and livers were used for quantitative polymerase chain reaction analysis of vitellogenin (vtg) mRNA expression at multiple time points. 10 μg TB/L induced anal fin elongation after 7 days of treatment (one-way ANOVA, p< 0.05) as did 0.1 and 1 μg TB/L at later time points (one-way ANOVA, p< 0.05). 10 μg TB/L significantly reduced hepatic vtg gene expression at all time points assessed (one-way ANOVA, p< 0.05). There was no correlation between anal fin elongation levels and vtg gene expression (Spearman's ρ, p> 0.05). In a separate experiment, female G. holbrooki and G. affinis were exposed to the vehicle control or 1 μg TB/L. Anal fins were used for qualitative gene expression analysis of the genes sonic hedgehog (shh), muscle segment homeobox C (msxC), and fibroblast growth factor receptor 1 (fgfr1) by in situ hybridization. Shh was expressed in the distal tip of the gonopodium while msxC and fgfr1 were more widely expressed along the same anal fin rays during androgen exposure. These data provide insight into the molecular pathways involved in anal fin elongation and pave the way for future work toward developing the mosquitofish into a bioindicator organism for endocrine disruptors.

AB - The Eastern and Western mosquitofish (Gambusia holbrooki and G. affinis) are potential bioindicator organisms for endocrine disruptors. Male mosquitofish have an elongated anal fin (gonopodium) used for internal fertilization whose formation is driven by androgens. Normal female mosquitofish have a normal, rounded anal fin which undergoes elongation into a gonopodium structure when female mosquitofish are exposed to androgenic chemicals. Significant issues with using mosquitofish as a bioindicator include the lack of knowledge on how anal fin growth in females corresponds to endpoints relevant to biological integrity and the lack of information on the molecular pathways that regulate anal fin growth. The objectives of this study were to understand how androgen-induced anal fin elongation relates to changes in endpoints related to the female reproductive system and to understand how anal fin elongation occurs in androgen-exposed female mosquitofish. To achieve these objectives, adult female G. holbrooki were exposed to a vehicle control or one of three doses of the androgen 17β-trenbolone (TB) at nominal concentrations of 0.1, 1 or 10 μg TB/L. Anal fin measurements were taken and livers were used for quantitative polymerase chain reaction analysis of vitellogenin (vtg) mRNA expression at multiple time points. 10 μg TB/L induced anal fin elongation after 7 days of treatment (one-way ANOVA, p< 0.05) as did 0.1 and 1 μg TB/L at later time points (one-way ANOVA, p< 0.05). 10 μg TB/L significantly reduced hepatic vtg gene expression at all time points assessed (one-way ANOVA, p< 0.05). There was no correlation between anal fin elongation levels and vtg gene expression (Spearman's ρ, p> 0.05). In a separate experiment, female G. holbrooki and G. affinis were exposed to the vehicle control or 1 μg TB/L. Anal fins were used for qualitative gene expression analysis of the genes sonic hedgehog (shh), muscle segment homeobox C (msxC), and fibroblast growth factor receptor 1 (fgfr1) by in situ hybridization. Shh was expressed in the distal tip of the gonopodium while msxC and fgfr1 were more widely expressed along the same anal fin rays during androgen exposure. These data provide insight into the molecular pathways involved in anal fin elongation and pave the way for future work toward developing the mosquitofish into a bioindicator organism for endocrine disruptors.

UR - http://www.scopus.com/inward/record.url?scp=84872201123&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84872201123&partnerID=8YFLogxK

U2 - 10.1016/j.aquatox.2012.12.007

DO - 10.1016/j.aquatox.2012.12.007

M3 - Article

C2 - 23314276

AN - SCOPUS:84872201123

VL - 128-129

SP - 163

EP - 170

JO - Aquatic Toxicology

JF - Aquatic Toxicology

SN - 0166-445X

ER -