+----------------SUBJ:V-N----------------+                                   
      +-------COMP:N-N(of)-------+             +---------COMP:V-N(in)--------+     
      |           +-MOD_ATT:N-ADJ+             |            +--MOD_ATT:N-ADJ-+     
      |           |       +MOD_AT+        +-NEG+            |         +MOD_AT+     
      |           |       |      |        |    |            |         |      |     
 Expression of __SP__ __NODE__ mRNA does not occur in unfertilized __SP__ oocytes .
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,oocyte)
MOD_ATT:N-ADJ (oocyte,unfertilized)
MOD_ATT:N-ADJ (oocyte,__SP__)