By Matthew Willett

Instant disease model: just add water.

Like futuristic sea monkeys, zebrafish (Brachydanio rerio) are easy to grow, easy to observe and cheap.

Unlike sea monkeys, zebrafish are useful disease models, vertebrates that mimic human organ structure. Nina Sawczuk, Atlanta-based Zygogen LLC's CEO, told BioWorld Today that's why her company can shop the fish to biotechnology and pharmaceutical companies as methods for target identification, validation and disease modeling.

And, she said, unlike the playful critters available in the back pages of comic books, the zebrafish eat sea monkeys, a.k.a. brine shrimp.

"Zebrafish are really a hot, emerging model organism that is shifting from research use to becoming a validated model for the human state and human diseases," Sawczuk said. "Their advantages are threefold: optical clarity - they're see-through and you can watch the development of organs; in angiogenesis you can watch blood vessels form - they're inexpensive - you can do a lot of experiments for less cost than mice; and finally, you can put them in 96-well plates and have embryos that live there for three to five days."

The company formed in July 1999 and opened labs at Georgia State University a year later. It now is fine-tuning its technology and seeking partnerships with biotechnology and pharmaceuticals companies.

"Our therapeutic areas of focus are angiogenesis, cardiology, neurodegenerative diseases and hematological diseases like thrombosis and leukemia," Sawczuk said. "What we do is use our transgenic zebrafish as disease models for screening small molecules and coming up with drug candidates."

That screening is born of libraries created with the company's Z-tag technology, which involves methods for making organs in the transparent zebrafish fluorescent.

"The key thing to understand, a thing that's somewhat humbling, is that the DNA for a zebrafish is 75 percent the same as human DNA," Sawczuk said. "A lot of the other 25 percent is similar, the same types of neurons that humans have more of, etc., so a lot of the basic gene families are represented. The other key thing is that zebrafish, as opposed to yeast, flies or worms, are vertebrates, so they've got a vertebrate system that's really cheap and easy to work with in large numbers."

Still in the start-up phase, Sawczuk said the company hopes to expand from seven employees to 12 by the end of the year, and she added that the company is pursuing its first $4 million in venture capital financing.

"We're still very early stage," Sawczuk said. "We opened labs last July, and based on our therapeutic areas of interest what we're doing is staging a panel of fish lines with fluorescent organs, as well as lines with multiple fluorescent organs, and those fish will be used as tools for tissue-specific assays. We'll market them for development or multiple uses, number one, making them into disease models.

"We're still on angel money, and we're looking for our first round of financing of $4 million," she said. "We'd like to have that in the second or third quarter, and we're actively in discussions with people on that."