Impacts of synthetic oestrogen and antioestrogen treatments on courtship and mating behaviours in male guppies (Poecilia reticulata)
(English)Manuscript (Other academic)
Understanding the neuroendocrinological mechanisms behind reproductive behaviour is fundamental when studying endocrine disruption. Neuroestrogen production is a key step in the activation of reproductive behaviours among vertebrates. The actions of estrogens are transmitted through estrogen receptors (ERs) in distinct brain nuclei. Here we report alterations in reproductive behaviours in guppy males following 55-day food treatments with the antiestrogen fulvestrant (ICI) and the synthetic oestrogen 17α-ethinylestradiol (EE2). Male courtship and mating attempts were severely reduced in EE2 treated males after both 27-30 and 41-55 days of treatment when paired with females. ICI treatment gave a significant reduction in the frequency of sigmoid display behaviour after 27-30 days of treatment, and an almost 2.5-fold increase in gonopodium thrusting after 41-55 days of treatment. ICI treated males also decreased their frequency in successful mating attempts in comparison to the control males. The neurological effects of ICI were confirmed by Real Time-PCR analysis for brain aromatase and ERα gene expression. ICI treatment suppressed aromatase expression to 64% and stimulated ERα gene expression by over 300%. These results indicate that oestrogen action via ERs may play an important role for the complete display of male courtship and mating behaviour in the guppy. The results also suggest that local steroids are involved in regulating brain aromatase expression and that the negative effects of EE2 on sexual behaviour are linked via endocrine disruption of gonadal function.
Brain aromatase, estrogen receptors, xenoestrogens, teleost reproduction, fulvestrant
Research subject Functional Zoomorphology
IdentifiersURN: urn:nbn:se:su:diva-26903OAI: oai:DiVA.org:su-26903DiVA: diva2:211717
ProjectsAromatase and androgens in fish reproductive behaviour