al·lo·type 
(ălə-tīp′)
(ălə-tīp′)n.
1. Taxonomy A biological specimen that is the opposite sex of a holotype.
2. Immunology Any of several variants in the constant region of a given class or subclass of immunoglobulins that are caused by allelic variation and differ from individual to individual.
al′lo·typic (-tĭpĭk) adj.
allo·ty′py (-tī′pē) n.