RT Journal Article
SR Electronic
T1 Tetrahymena Mutants With Short Telomeres
JF Genetics
JO Genetics
FD Genetics Society of America
SP 643
OP 650
VO 150
IS 2
A1 Ahmed, Shawn
A1 Sheng, Hong
A1 Niu, Luming
A1 Henderson, Eric
YR 1998
UL http://www.genetics.org/content/150/2/643.abstract
AB Telomere length is dynamic in many organisms. Genetic screens that identify mutants with altered telomere lengths are essential if we are to understand how telomere length is regulated in vivo. In Tetrahymena thermophila, telomeres become long at 30°, and growth rate slows. A slow-growing culture with long telomeres is often overgrown by a variant cell type with short telomeres and a rapid-doubling rate. Here we show that this variant cell type with short telomeres is in fact a mutant with a genetic defect in telomere length regulation. One of these telomere growth inhibited forever (tgi) mutants was heterozygous for a telomerase RNA mutation, and this mutant telomerase RNA caused telomere shortening when overexpressed in wild-type cells. Several other tgi mutants were also likely to be heterozygous at their mutant loci, since they reverted to wild type when selective pressure for short telomeres was removed. These results illustrate that telomere length can regulate growth rate in Tetrahymena and that this phenomenon can be exploited to identify genes involved in telomere length regulation.