+------------SUBJ:V-N------------+              
      +----COMP:N-N(of)---+            |              
      |           +MOD_ATT+            +COMP:V-N(+    
      |           |       |            |         |    
 Expression of __SP__ __NODE__ gene occurs in __SP__ .
COMP:N-N(of) (expression,__NODE__)
MOD_ATT:N-ADJ (__NODE__,__SP__)
SUBJ:V-N (occur,expression)
COMP:V-N(in) (occur,__SP__)