16547
This genome comparison revealed that most receptor and peptide genes were clustered in three GAC linkage groups and suggested that the ancestral forms of five peptide subfamilies ( corticotropin - releasing hormone - like , calcitonin - like , parathyroid hormone - like , glucagon - like , and growth hormone - releasing hormone - like ) and their cognate receptor families emerged through tandem local gene duplications before two rounds ( 2R ) of whole - genome duplication .
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Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
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