ABSTRACT
Nematodes have been model organisms for developmental biologists for a century. The nematode Caenorhabditis elegans occupies a unique place in developmental genetics because it is the only animal for which the complete cell lineage is known, from the single cell of the zygote to the thousand or so differentiated cells of the adult. The number of entomopathogenic infective juveniles formed in nature is dependent on the number of nematodes present in the insect cadaver. The dauer juvenile of entomopathogenic nematodes is capable of tolerating stresses fatal to other developmental forms, and of infecting new hosts, and is therefore also called an infective juvenile or infective third-stage juvenile. Conventional and molecular genetics have great potential for improving entomopathogenic nematode/bacterial symbiont complexes to yield powerful biological pest control agents. The genetic consequences of the various sex determination mechanisms differ, and the strategy for any kind of genetic analysis depends upon the mode of reproduction of the organism.
