6731
We have cloned and sequenced a 3574 - bp Bacillus subtilis ( Bs ) DNA fragment located between the nrdA and citB genes at about 169 degrees on the chromosome .
 GENE: nrdA; GENE: citB genes
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: GENE 
Text: {0} 
 Entities: nrdA, citB genes 
Answer:
 GENE: nrdA; GENE: citB genes