Cloning, sequencing and In situ localisation of guppy brain aromatase, cyp19b
(English)Manuscript (Other academic)
Oestrogens are biosynthesised by cytochrome p450-aromatase (Cyp19). Brain oestrogens serve several important functions of which nerve protection, cell proliferation, nerve development and behaviour control are a few. Teleost brain aromatase activity is exceptionally high (between 100-1000 times) compared to mammals and birds. We have successfully cloned and sequenced a 950 bp long partial fragment of the guppy CYP19B gene (PrCyp19b) derived from adult brain mRNA. Sequence alignment of translated amino acid sequence shows PrCYP19b having high sequence similarity to teleost brain aromatase. Anatomical distribution of PrCYP19b expression in adult guppy brains was studied using in situ-hybridisation with an antisense riboprobe synthesised from the cloned PrCYP19b gene. Expression of brain aromatase appeared at ventricular surfaces of the ventral telencephalic zones and the pre-optic area, in the hypothalamus, the pituitary gland, optic tectum and the cerebellum. This pattern is similar to previously reported distribution of brain aromatase in other teleosts. Measurement of brain aromatase activity in telencephalon, mesencephalon/diencephalon and rhombencephalon revealed female guppies producing the most oestrogens in mesencephalon/diencephalon, whereas males produces the most oestrogens in both telencephalon and mesencephalon/diencephalon. This indicates that brain oestrogen production is sexually dimorphic in the guppy and may serve different functions in the two genders.
Brain aromatase, teleost brain, In Situ-hybridisation, anatomical distribution
Research subject Functional Zoomorphology
IdentifiersURN: urn:nbn:se:su:diva-26905OAI: oai:DiVA.org:su-26905DiVA: diva2:211937
ProjectsAromatase and androgens in fish reproductive behaviour