MATING IN THE NEMATODE PARASITE STRONGYLOIDES-RATTI - PROOF OF GENETIC EXCHANGE

Strongyloides, a parasitic nematode, has a complex life cycle that rep resents a transition between free-living and purely parasitic ways of life. By using minisatellite DNA fingerprinting, we have detected a la rge number of polymorphic loci in cloned lines of S. ratti. In control led crosses between free-living adults of S. ratti, we show that genet ic exchange, consistent with normal sexual reproduction, occurs. This is in contrast to earlier cytological studies which claimed that repro duction in this organism was by pseudogamy, and thus that inheritance was maternal only.