+------------SUBJ:V-N------------+                                   
      +-------COMP:N-N(of)-------+     +---------COMP:V-N(in)---------+    
      |           +-MOD_ATT:N-ADJ+     |         +-----MOD_ATT:N-N----+    
      |           |       +MOD_AT+     |         |            +MOD_ATT+    
      |           |       |      |     |         |            |       |    
 Expression of __SP__ __NODE__ mRNA occurs in uterus from pregnant __SP__ .
COMP:N-N(of) (expression,mRNA)
MOD_ATT:N-ADJ (mRNA,__SP__)
MOD_ATT:N-ADJ (mRNA,__NODE__)
SUBJ:V-N (occur,expression)
COMP:V-N(in) (occur,__SP__)
MOD_ATT:N-N (__SP__,uterus)
MOD_ATT:N-ADJ (__SP__,pregnant)