GLIN==> Illinois-Indiana Sea Grant News: Building a Better Fish Using Embryonic Stem Cells

[Irene Miles <miles@uiuc.edu>]

December 8, 2004
Source: Paul Collodi (765) 494-9280
 
Building a Better Fish Using Embryonic Stem Cells
 
In the world of medicine, research on embryonic stem cells offers the
possibility of curing fatal and debilitating diseases. In the world of
aquaculture, embryonic stem cell research may enhance production and
reduce environmental risks.
 
With funding from Illinois-Indiana Sea Grant, a team of Purdue University
scientists have developed fish embryonic stem cell lines that can
potentially be used to modify the genetic characteristics of any fish
species. Paul Collodi and his team established these cultured cells from
zebrafish that can form viable eggs or sperm when transplanted into an
embryo. The cells may be used in the future to introduce specific
alterations into the fish chromosomes.
 
One of the ultimate goals of this research is to use these cell lines to
grow fish that are lacking the hormone necessary for fertility (which can
be reversed by adding the hormone to the fish?s diet). Controlling
fertility in aquaculture production offers a way to reduce the threat of
non-native species escaping and disrupting the balance of local
waterways. A prime example of an invasive species escaping from
aquaculture production is Asian carp. These fish have moved up the
Mississippi River and pose a threat to the Great Lakes. 
 
?If this technology is successful, it also offers many possibilities of
enhancing aquaculture production through the manipulation of specific
desirable genes. In an aquaculture setting, we may be able to control
growth, disease, and reproduction rates, or change species
characteristics and improve survival capabilities,? said Collodi.
?Zebrafish possess a number of characteristics that make them ideal for
developing this technology, including that they are relatively
inexpensive and easy to maintain in the laboratory, but once we
successfully develop gene-transfer methods, they will be applied to
commercially important species.? 
 
?This work may also have implications for research into the genetic basis
for human disease and the development of new drugs,? said Collodi. ?We
are doing very basic research into gene function during embryonic
development, which may offer insight into developmental abnormalities and
help pinpoint which genes play a role in disease.? 
 
This project has involved a series of difficult steps. First, the
scientists developed a technique to grow zebrafish embryonic cells in a
culture dish long enough to be practical for genetic research. Stem cells
have the ability to develop into any kind of tissue, which makes them
particularly useful for introducing genetic alterations. For example, it
is critical that when these cells are transplanted into a host embryo,
they have the ability to differentiate into sperm or egg, providing the
means to pass on the altered trait.
 
The next step was to make specific genetic alterations in embryonic stem
cells and to isolate these altered cells in a culture dish. The
researchers used a red fluorescent protein gene as a way of identifying
these cells. Now Collodi?s team is working to transfer the selected cells
that carry the genetic alteration back into an embryo to produce fish
with the altered trait. ?We are using pigmentation pattern to determine
if the embryonic stem cells contributed to the germ line of the host
embryo and the genetic alteration was transferred to the next
generation,? he said.
 
Collodi now has funding from the USDA and the National Institute of
Health to continue this work. ?The initial support from Illinois-Indiana
Sea Grant allowed our lab to generate this promising data that has led to
much larger funding opportunities,? he added.

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The Illinois-Indiana Sea Grant College Program is one of more than 30
National Sea Grant College Programs. Created by Congress in 1966, Sea
Grant combines university, government, business and industry expertise to
address coastal and Great Lakes needs.  Funding is provided by the
National Oceanic Atmospheric Administration (NOAA), U. S. Department of
Commerce, the University of Illinois at Urbana-Champaign and Purdue
University at West Lafayette, Indiana.

Irene Miles
Illinois-Indiana Sea Grant
376 NSRC
1101 W. Peabody Dr.
Urbana, Il 61801
(217) 333-8055
FAX (217) 333-8046