8964
Specifically , I use molecular markers that identify particular neuroectodermal domains , all neuroblasts or individual neuroblasts , to show that in DER mutant embryos ( 1 ) intermediate column neuroblasts do not form , ( 2 ) medial column neuroblasts often acquire identities inappropriate for their position , while ( 3 ) lateral neuroblasts develop normally .
 DER mutant
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: GENE 
Text: {0} 
Answer:
 DER mutant