2178
First , a pet54 : : LEU2 cytoductant bearing the ' short ' mitochondrial genome that lacks both COX1 introns aI5 alpha and aI5 beta is defective only in COX3 gene expression and not in COX1 mRNA splicing or mRNA translation .
 pet54, LEU2, COX1 introns, aI5 alpha, aI5 beta, COX3 gene, COX1 mRNA
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: GENE 
Text: {0} 
Answer:
 pet54, LEU2, COX1 introns, aI5 alpha, aI5 beta, COX3 gene, COX1 mRNA