1759
In the present study , the AHR1 LBD sequences of 86 avian species were studied , and differences at amino acid sites 256 , 257 , 297 , 324 , 337 , and 380 were identified .
 Chemical: amino acid
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: amino acid