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Title:

Sex reversal and sex differentiation in Atlantic salmon (Salmo salar)

Project Number:

2018-121

Organisation:

Deakin University Warrnambool Campus

Principal Investigator:

Luis O. Afonso

Project Status:

Current

FRDC Expenditure:

$99,326.00

Program(s):

Industry

Need

Based on the National Fishing and Aquaculture RDE strategy 2016, our project relates to Strategic Goal 3: Benefits and value from fisheries and aquaculture resources (productivity and profitability) are maximised, and aquaculture production increased. Priority area: Develop new technologies and systems to improve the efficiency of production methods. This project is needed because the Australian Atlantic Salmon Industry is lacking basic and applied knowledge that could lead to the development of a reliable, non-steroidal method to produce all-female populations of Atlantic salmon. One of the drivers of this project is the fact that eliminating males from the production cycle (grow-out period), will reduce the effects of precocious sexual maturation, including reduced growth, reduced flesh quality, and susceptibility to diseases. As a consequence of eliminating males from the production cycle is a concomitant increase in overall productivity (biomass produced) and profitability We will use genetic and morphological techniques to improve our understanding of sex differentiation in Atlantic salmon. This knowledge is needed to inform the exact period that sex reversal treatments with exogenous substances are more effective to produce neo-males. This exact timing can then be used in the trial of next generation non-steroidal substances, ensuring that they have the greatest chance of success. This will be the first time that detailed gene expression and morphological information will be collected throughout the entire period of sexual differentiation.

Objectives

1. Investigate morphological sex differentiation processes in male and female Atlantic salmon larvae

2. Quantify the expression of several key genes involved in sex differentiation in male and female Atlantic salmon embryo’s and male and female Atlantic salmon larvae (gonadal and estrogenic non-gonadal tissues)

3. Investigate the effects of MDHT treatment on expression of several key genes involved in sex differentiation in female Atlantic salmon larvae (gonadal and estrogenic non-gonadal tissues)

4. Investigate the effects of DMSO on the masculinizing potential of a single MDHT immersion treatment in female Atlantic salmon.

5. Investigate the effects of the aromatase inhibitor letrozole on expression of several key genes involved in sex differentiation in female Atlantic salmon larvae (gonadal and estrogenic non-gonadal tissues)