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GenSAT (Gene Expression Nervous System Atlas) Project Announced

Public release date: 29-Oct-2003
Contact: Lynn Love
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212-327-8977
Rockefeller University

Unprecedented genetic access to brain provided by Rockefeller University scientists

For scientists studying the brain, this week's Nature announces a remarkable new map describing previously uncharted
territory, plus the means of exploring the new horizons for themselves. Rockefeller University scientists led by Nat
Heintz, Ph.D., and Mary Beth Hatten, Ph.D., are well under way on a genetic atlas of the mammalian brain that provides
unprecedented access to central nervous system regions, cell classes and pathways.

"Researchers studying degenerative and developmental diseases from Parkinson's and Huntington's to autism and epilepsy
now will have genetic access to the brain without all the effort required of doing their own molecular genetics from
scratch," says Heintz. "Gensat will advance the experimentation that can be done based on the information provided in
the atlas; to me this is the key contribution of our project."

The project, called Gensat (Gene Expression Nervous System Atlas) employs a method for manipulation of "bacterial
artificial chromosomes" or BACs, developed by project co-leader Heintz, professor and head of the Laboratory of
Molecular Biology at Rockefeller and an investigator at the Howard Hughes Medical Institute. BACs in an early form
provided the backbone of The Human Genome Project; Heintz discovered how to manipulate them by inserting, changing or
deleting parts of the large gene sequences composing them. Once created, the modified BACs for individual genes are
inserted into the genome of laboratory mice to assess gene expression.

The BAC technology provides unparalleled insight because it identifies the actual cell types in the brain in which
individual genes express themselves. Heintz also added a reporter gene to the BACs so that cells with the selected gene
activity glow bright green. Many new brain cell types or subtypes have been discovered in this project as a result of
the potent tool. (Traditional methods of genetic analysis such as in situ hybridization cannot distinguish among cell
types for gene expression, and therefore are not as powerful.)

Gensat comes with the accoutrements necessary for scientists anywhere to further improve our knowledge of the brain and
its diseases. Gensat is a fully public, searchable database of gene expression in all central nervous system cell types
for individual genes. What's more, Gensat provides the tools (BAC vectors and transgenic mice) used in the project for
researchers interested in following up on new disease-based insights revealed in the atlas. One hundred-fifty genes are
analyzed in the new database at www.gensat.org, with 100 more genes scheduled for posting soon.

"We are providing more information in our database than has ever been known in the central nervous system," says
Hatten, professor and head of the Laboratory of Developmental Neurobiology at Rockefeller. "There isn't a single gene
among the 150 currently on our public atlas that has been studied in the range of detail that we have provided. If
biologists tend to explore things locally in great detail, we've started examining a global economy of the central
nervous system."

Gensat analyzes up to five genes per week in a high-throughput laboratory space provided by The Rockefeller University.
Heintz and Hatten plan to analyze gene expression in all central nervous system cell types for 250 to 300 genes per
year.

Landmarks in the brain

Maps are valuable when they exhibit distinguishing features of the landscape. The same is true for Gensat. When the two
Rockefeller scientists conceived the project four years ago, Hatten knew she would need to put her considerable
expertise in imaging the brain to work if Gensat was going to succeed. Today, the Gensat project recreates for
scientists and students the experience of sitting down to look at brain specimens at a microscope. Seeing genes
expressed in every cell type in the brain, and viewing that expression in a traditional, anatomical format, provide
researchers with more insights about the function of genes.

To achieve this result, the project's automated microscope records mouse brain specimens for every gene in the atlas at
three developmental stages. The images are captured at high resolution, checked for accuracy by several of the 20
researchers involved with the project, annotated and prepared for inclusion in the database.

The organizational challenge alone for such a large-scale project is impressive. But Heintz and Hatten faced more than
an organizational challenge when they started out. The means of displaying high-resolution digital images on the scale
they envisioned simply did not exist.

"It was like going into a bike shop and designing a bike that no one has ever imagined before," says Hatten. "All the
components were available, but we had to put them together and design the computing systems to run them for the first
time."

The lead duo were fortunate to attract gifted scientists and a programmer to the project, without whom, they would
never have achieved all the significant technical infrastructure and refinements required at every stage. The
scientists include Shiaoching Gong, Chen Zheng, Martin Doughty, Kasia Losos and programmer Nick Didkovsky. Heintz and
Hatten describe this group as "some of the most talented young researchers we've ever worked with." Remarkably,
Didkovsky, without prior exposure to science, worked closely with Hatten to build an operating system for Gensat from
the ground up.

This year, Gensat has received multi-year funding from the NIH's National Institute of Neurological Disorders and
Stroke. But in the three years that it took to refine the imaging, computing system and BAC methodology as well as set
up the large-scale mouse transgenic operation that powers the project, Hatten and Heintz have relied on The Rockefeller
University's tradition of supporting researchers undertaking risky, but potentially important science.

"Without the university, this project simply would not exist," says Hatten. "Rockefeller has made it all work out;
they've funded all computer systems, a full-time software programmer, as well as built us lab space for the researchers
working together on this project."

"A lot of scientists form companies," says Heintz. "We thought about that, too, but we didn't want to see so much
valuable information and the tools we created reserved for scientists with big resources to buy database information,
vectors and transgenic mice for their experiments." The university and NIH have helped fulfill Heintz and Hatten's goal
of keeping this project truly public.

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SOURCE: EurekAlert, DC
http://www.eurekalert.org/pub_releases/2003-10/ru-ge102903.php

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