+------------SUBJ:V-N------------+-----------COMP:V-N(in)----------+    
      +-------COMP:N-N(of)-------+     |             +----MOD_ATT:N-N----+    
      |           +-MOD_ATT:N-ADJ+     |             |   +-MOD_ATT:N-ADJ-+    
      |           |       +MOD_AT+     |             |   |      +MOD_ATT:+    
      |           |       |      |     |             |   |      |        |    
 Expression of __SP__ __NODE__ mRNA occurs in 170.0 day old embryonic __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__,day)
MOD_ATT:N-ADJ (__SP__,old)
MOD_ATT:N-ADJ (__SP__,embryonic)