syngen and mating types in ciliates

[Detlef D. Leipe]

Dear Fellow Protistologists,

The books on my shelf do not offer much help in understanding the 
terms syngen and mating type in ciliates.  I would be grateful 
receiving exact definition for these term and I would also like 
to know if there is any ambiguity about their usage (do all people 
use them in the same sense?).  Last question: are these terms used 
outside the ciliatological community?

All help appreciated,


   Detlef Leipe