Speckled stripe zebrafish originally found in Ganges river has been making a splash in the scientific world. The US Food and Drug Administration’s (FDA’s) National Centre for Toxicological Research (NCTR) scientists are using the embryos and larvae of zebrafish as models to study how drugs and chemicals affect the organs and systems. According to researchers this will help get best possible picture of the hazard that would be involved in taking a drug before it is tested in human patients.
At the FDA research centre in Arkansas, scientists are using the embryos and larvae (up to five- to six-days old) of these small, transparent fish to conduct large numbers of chemical, genetic or pharmaceutical tests. “We can test 20 different concentrations of a drug or chemical in just ten minutes and screen as many as 384 embryos within the same time period,” said FDA research biologist, Dr Jyotshna Kanungu.
NCTR is using the zebrafish in a number of different studies. For instance, Scientists are studying the effects of ketamine (a paediatric anaesthetic regulated by FDA) on the overall development of embryos as well as on the cardiovascular and nervous systems. The transgenic (genetically-altered) zebrafish embryos have been used by the scientists to investigate the effect of copper nanoparticles — frequently used in medical devices, paints and fabrics — on biological systems. Zebrafish have neuromasts (small sensory patches) similar to those lining the inner ear of humans. Using dyes, scientists can stain the neuromasts to make them more visible and monitor the effects of compounds such as nicotine, ketamine, and ethanol on hearing. According to Dr Jyotshna Kanungo, PhD “Zebrafish make terrific preclinical trial subjects, as “They are similar to humans in many ways and have a number of advantages over the other animals used in experimental research, such as laboratory mice and rats because of their fast development and low cost of maintenance.”
Surrounded by 288 fish tanks in her lab, Dr Kanungo notes that unlike the fruit flies and the nematode worm, other popular species studied in laboratories, zebrafish are vertebrates, as are humans. Most of their genes — more than 80 percent — have a human counterpart, she says.