Environmental and neuroendocrine control of pubertal initiation in Atlantic salmon
The Brain-Pituitary-Gonad axis regulates reproduction integrating hormonal messaging from internal and environmental stimuli. Luteinizing hormone (Lh) and follicle-stimulating hormone (Fsh) produced by the pituitary gland are main hormones involved in reproduction. Available knowledge suggests that in mammals, both Lh and Fsh, produced by the same cell type, are required to trigger the entry into puberty. In fish, where Lh and Fsh are produced by two distinct cell types, evidence suggests a major role of Fsh in the regulation of this developmental process. However, knowledge about the regulation of Fsh synthesis and secretion is still fragmentary.
The aim of this project is to identify possible regulators of pubertal initiation in Salmo salar, studying and comparing the expression of candidate receptors in Fsh-producing cells before and after puberty.
A better understanding of the regulation of puberty may reduce the future need for exogenous hormones treatment increasing social acceptance regarding farmed fish for both restocking or commercial farming purposes.
We are working with Atlantic salmon parr, comparing the developmental profile from maturing and non maturing fish during pubertal development occurring in spring.
In total 36 fish will be culled. Pituitaries fixated in PFA will be collected from 36 fish for gene localization study via fluorescent microscopy.
Fish will only experience a short netting stress .They will be anaesthetized immediately (MS-222; 50 mg/L) and therefore lose consciousness within 15 seconds after being exposed to the stressor, reducing delayed stress effects (plasma cortisol levels in stressed fish peak at around 20 minutes to one hour after being exposed to a stressor).
Replacement: This study focuses on the regulation of the secretion of one of the most important hormones involved in reproduction, Fsh. We are interested in Fsh regulation during pubertal development, which is influenced by environmental, social, behavioral, hormonal and neuronal stimuli acting together. These complex stimuli cannot be replicated in vitro, and therefore live animals must be used.
Reduction: Following consultation with a bio-statistician, the minimum number of fish will be sampled that will give statistically relevant data. According to power analysis from a previous pilot study, 6 biological replicates are required in order to accept differential expression in some of the genes analyzed in the study (e.g. gnrhr 1A1) between groups.
Refinement:The health and well-being of all animals, including symptoms of distress, will monitored on a daily basis by qualified technical staff. All participants, including the principle researcher (Elia Ciani) are fully accredited with FELASA documentation.
The aim of this project is to identify possible regulators of pubertal initiation in Salmo salar, studying and comparing the expression of candidate receptors in Fsh-producing cells before and after puberty.
A better understanding of the regulation of puberty may reduce the future need for exogenous hormones treatment increasing social acceptance regarding farmed fish for both restocking or commercial farming purposes.
We are working with Atlantic salmon parr, comparing the developmental profile from maturing and non maturing fish during pubertal development occurring in spring.
In total 36 fish will be culled. Pituitaries fixated in PFA will be collected from 36 fish for gene localization study via fluorescent microscopy.
Fish will only experience a short netting stress .They will be anaesthetized immediately (MS-222; 50 mg/L) and therefore lose consciousness within 15 seconds after being exposed to the stressor, reducing delayed stress effects (plasma cortisol levels in stressed fish peak at around 20 minutes to one hour after being exposed to a stressor).
Replacement: This study focuses on the regulation of the secretion of one of the most important hormones involved in reproduction, Fsh. We are interested in Fsh regulation during pubertal development, which is influenced by environmental, social, behavioral, hormonal and neuronal stimuli acting together. These complex stimuli cannot be replicated in vitro, and therefore live animals must be used.
Reduction: Following consultation with a bio-statistician, the minimum number of fish will be sampled that will give statistically relevant data. According to power analysis from a previous pilot study, 6 biological replicates are required in order to accept differential expression in some of the genes analyzed in the study (e.g. gnrhr 1A1) between groups.
Refinement:The health and well-being of all animals, including symptoms of distress, will monitored on a daily basis by qualified technical staff. All participants, including the principle researcher (Elia Ciani) are fully accredited with FELASA documentation.