1391
These results suggest that beta - 1 may act as a tissue - specific , trans - acting regulator of the expression of the beta - zein gene in developing maize endosperm .
 beta - 1, beta - zein gene
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: GENE 
Text: {0} 
Answer:
 beta - 1, beta - zein gene