In edited versus unedited cells, the authors used ChIP to determine which DNA sequences in the FXS genome were bound to specific proteins. Which of the following related statements is true?
a) An antibody to the FMR1 DNA sequence copurified RNA polymerase
b) When modified (edited) using the dCas9-TET system, RNA polymerase II was associated with the FMR1 locus.
c) Mock cells were also treated with dCas9-TET.
d) When modified (edited) using the dCas9-TET system, a modified type of histone 3 that is associated with silenced DNA was found to be associated with the FMR1 locus.