heteropyknosis

noun

het·​ero·​pyk·​no·​sis

variants also heteropycnosis

ˌhet-ə-rō-pik-ˈnō-səs 

: the quality or state of some chromosomes or of parts of some chromosomes in a nucleus of taking up more stain and being more tightly coiled or of taking up less stain and being less tightly coiled than is usual compare isopyknosis

heteropyknotic adjective

also heteropycnotic

-ˈnät-ik