+---------------COMP:V-N(in)---------------+    
      +------------SUBJ:V-N------------+         +----------MOD_ATT:N-ADJ---------+    
      +-------COMP:N-N(of)-------+     |         |       +-------MOD_ATT:N-N------+    
      |           +-MOD_ATT:N-ADJ+     |         |       |        +--MOD_ATT:N-N--+    
      |           |       +MOD_AT+     |         |       |        |        +MOD_AT+    
      |           |       |      |     |         |       |        |        |      |    
 Expression of __SP__ __NODE__ mRNA occurs in __SP__ extensor digitorum longus muscle .
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,muscle)
MOD_ATT:N-ADJ (muscle,__SP__)
MOD_ATT:N-N (muscle,extensor)
MOD_ATT:N-N (muscle,digitorum)
MOD_ATT:N-N (muscle,longus)