From A to Zebrafish
[-Back to Seeking Immunity-]

Like their mammalian namesakes, zebrafish are striped for camouflage protection. When moving as a herd or a school, the stripes of the zebra and zebrafish make it difficult for predators to focus on a single individual.

Zebrafish in the wild are found in the Ganges River and in rice paddies in India and Burma. The late George Streisinger, a researcher at the University of Oregon, is widely considered to be the founding father of zebrafish development and genetic research.

Zebrafish are hardy and can tolerate fluctuations in water temperature. They prefer water that's 28 degrees C, with 14 hours of daylight and 10 hours of darkness. The room temperature in the zebrafish facility is a constant 82 degrees.

UMaine's zebrafish facility was started in 1999 with 250 zebrafish purchased from the University of Oregon, home of the Zebrafish International Resource Center. The brood stock was from a specially bred scientific line called AB. Today, the UMaine facility houses more than 40,000 zebrafish. They are kept in 648 small or 56 large tanks.

Research assistant Mark Nilan manages UMaine's zebrafish facility. The native of Nebraska studied aquaculture at UMaine, conducting research at the Center for Cooperative Aquaculture Research in Franklin. He joined the zebrafish lab in 2003 and helped design its intricate system that pumps UV-sterilized water to the self-cleaning, recirculating tanks. The water and filtration system are computer monitored, with a backup generator in case of power outage.

Zebrafish are vertebrates with a less complex immune system than that of mammals, yet they have comparable structure. Scientists at UMaine are trying to identify factors that influence regulation of the innate immune response, focusing primarily on the molecular activity of what's called the Toll signaling pathway that goes into motion at the first sign of infection. Ultimately, researchers hope to learn enough about the innate immune response and its role in adapted immune response to begin to develop methods for intervention that can be applied to mammals and fish.

Zebrafish make good models for studying aspects of mammalian and fish health because they reproduce and grow rapidly, and embryos are easily manipulated and propagated. Females can lay up to 300 eggs a week. Embryonic development inside each of the transparent eggs can be viewed under a microscope. Zebrafish grow from a single cell to a fish-shaped organism within 24 hours of fertilization; baby fish called fry hatch within 72 hours.