+----------------SUBJ:V-N----------------+----------COMP:V-N(in)---------+    
      +-------COMP:N-N(of)-------+             |        +------MOD_ATT:N-N-----+    
      |           +-MOD_ATT:N-ADJ+             |        |            +MOD_ATT:N+    
      |           |       +MOD_AT+        +-NEG+        |            |   +MOD_A+    
      |           |       |      |        |    |        |            |   |     |    
 Expression of __SP__ __NODE__ mRNA does not occur in ovary from 50 day old __SP__ .
COMP:N-N(of) (expression,mRNA)
MOD_ATT:N-ADJ (mRNA,__SP__)
MOD_ATT:N-ADJ (mRNA,__NODE__)
SUBJ:V-N (occur,expression)
NEG (occur,not)
COMP:V-N(in) (occur,__SP__)
MOD_ATT:N-N (__SP__,ovary)
MOD_ATT:N-N (__SP__,day)
MOD_ATT:N-ADJ (__SP__,old)