To test that the protein changes they saw actually were critical to the formation of the ventral furrow, Minden and his colleagues used a technique called RNA interference to greatly decrease the expression of genes for altered proteins in the fruitfly embryos. They found that that the embryos failed to form ventral furrows.
"Our study demonstrates that the formation of the ventral furrow is a complex process that encompasses nearly all cellular processes," said Minden.
The scientists also found that only one protein was activated at the exact moment when cells changed shape. This protein is part of a complex cellular machine called the proteosome, which is responsible for breaking down proteins.
"This finding suggests that right before cells in the ventral furrow change shape, they break down proteins, perhaps the cytoskeletal proteins that preserve their columnar shape," said Minden.
To compare the abundance and kinds of proteins made at different stages of development, Minden and his colleagues used Difference Gel Electrophoresis, a tool created by Minden and commercialized by Amersham, plc. Using DIGE, scientists label two protein samples with different color fluorescent dyes and then run both samples on the same gel, which separates proteins by size and electrical charge. A computer program analyzes the gel to detect differences in the abundance and presence of all the proteins from the two samples and reports them back to the investigator.
"Our study is really a starting point. Comparing the proteomes at different stages in an anima
'"/>
Contact: Lauren Ward
wardle@andrew.cmu.edu
412-268-7761
Carnegie Mellon University
30-Mar-2004