In yeast, {TAIL ~ SIR2} is required for {HEAD ~ transcriptional silencing} , and is also involved in suppressing rDNA recombination and controlling life span  
In yeast , { TAIL ~ SIR2 } is required for { HEAD ~ transcriptional silencing } , and is also involved in suppressing rDNA recombination and controlling life span
OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH