nofima.no
Creating value
2013
25
Financed by:
The Research Council
of Norway
Adrijana Skugor moves on to studying early onset of sexual maturity in salmon.
photo: Jon-Are Berg-Jacobsen © nofima
Farmed cod that escape can also affect the genes of
wild fish. Nofima scientist Adrijana Skugor has examined
biological mechanisms that control development of the
sex organs in cod.
She has studied both individual genes and the whole
cod genome to obtain more knowledge about how the
germ cells of the embryo develop into eggs and sperm.
A “dead end” shows the way:
Skugor made use of
the knowledge she gained while studying zebrafish.
In zebrafish, the dead end gene (DnD) is necessary for
development of germ cells, and she has now studied the
significance of this gene in Atlantic cod.
She injected cod embryos with a molecule that blocks
DnD and found that inactivation of the gene stops sexual
maturation in cod too. Skugor used micro array screen-
ing to study the effects of DnD inactivation in a wider
context.
Transferring knowledge to salmon research:
“We now know that DnD is a good candidate for inhibi-
tion of germ cell development,” says Skugor. “But the
method used is costly and complicated and cannot be
used commercially. It has however been important in the
work of developing tools that make it easier to obtain
knowledge about how the cells develop.”
As a commercial method, it may be better to block
the dead end proteins in the mother fish, rather than
blocking the dead end gene in the embryo. Skugor will
establish this strategy in salmon, in a project financed by
the Norwegian Seafood Research Fund, as early sexual
maturation is also a major problem in salmon farming. In
this way, much of what has been learned from study-
ing cod may be brought into the work on salmon, in the
same way as Skugor previously made use of knowledge
from zebrafish studies.
“Skugor’s research has improved our knowledge
about the differentiation of germ cells and about the
general embryonic development of Atlantic cod”, says
supervisor and Senior Scientist Øivind Andersen at
Nofima.
Early onset of sexual maturity is a great problem in cod aquaculture
due to negative effects on growth, feed utilisation and health.
Stops sexual maturation in cod
