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