2145
In addition , 269 mice from a ( Mus spretus x C57BL / 6J ) F1 x C57BL / 6J interspecific backcross were also used to order marker loci and calculate intergene distances for this region .
 None
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: GENE 
Text: {0} 
Answer:
 None