NAEGLERIA - A RESEARCH PARTNER FOR CELL AND DEVELOPMENTAL BIOLOGY

Organisms in the genus Naegleria offer special opportunities for resea rch in contemporary biology. The dramatic cell differentiation from am ebae to flagellates is unique among eukaryotes in the rapidity, synchr ony, reproducibility, homogeneity, and accessibility of a major phenot ypic change. Environmental signals initiate a progressive signal trans duction pathway in which genes are turned on, including those for seve ral calcium-binding proteins, and newly synthesized proteins become lo calized in newly assembled organelles, including the centriole-like ba sal bodies, with the overall consequence that the cell changes its sha pe, motility, and behavior. This essay reviews research opportunities for which Naegleria excels, as well as interesting aspects of its biol ogy that provide challenges for future investigations. Because these o rganisms alternate between two major eukaryotic motility forms, their phylogenetic position is also provocative. Although there are hints th at Naegleria is capable of sexual reproduction in nature, mating has n ot yet been observed in the laboratory. In order to fully exploit the opportunities offered by this wonderful experimental system we are wor king to develop means to do genetic manipulation, in particular via DN A-mediated transformation.