2297
We used nucleotide sequence data from two mtDNA genes ( COI and 16S rDNA ) and three nuclear genes ( 28S rDNA , 18S rDNA , and ITS1 ) to estimate phylogenetic relationships among 47 described and one undescribed species of Branchiobdellida .
 nucleotide
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 nucleotide