Telomerase activity and differential expression of telomerase genes and c-myc in chicken cells in vitro.
This study examined telomerase activity and gene expression profiles for three genes in Gallus gallus domesticus: telomerase reverse transcriptase (chTERT), telomerase RNA (chTR), and c-myc. Expression of these genes was studied in chicken embryonic stem (chES) cells, chicken embryo fibroblasts (CEFs), and DT40 cells using quantitative real-time polymerase chain reaction. Our results establish that, relative to transcription levels in telomerase-negative CEFs, chTERT and chTR are up-regulated in telomerase-positive chES cells. Transcription levels of chTERT, chTR, and c-myc are dramatically up-regulated in telomerase-positive DT40 cells, relative to CEFs and chES cells. These results are consistent with a model in which telomerase activity is up-regulated in proliferating embryonic stem cells requiring stable telomeres to endure multiple rounds of cell division; down-regulated in differentiated, lifespan-limited cells; and dramatically up-regulated in immortalized, transformed cells for which uncontrolled proliferation is correlated with c-myc dysregulation and telomerase activity.
Department of Animal Science, University of California, Davis, California 95616, USA.
Susan E
SE
Swanberg
William S
WS
Payne
Henry D
HD
Hunt
Jerry B
JB
Dodgson
Mary E
ME
Delany
D000818:Animals; D002478:Cells, Cultured; D002642:Chick Embryo; D002645:Chickens; D004268:DNA-Binding Proteins; D005347:Fibroblasts / Q000166:cytology / Q000201:enzymology*; D005786:Gene Expression Regulation / Q000502:physiology*; D016259:Genes, myc / Q000502:physiology*; D012313:RNA / Q000378:metabolism*; D019098:Telomerase / Q000378:metabolism*; D014158:Transcription, Genetic / Q000235:genetics
D004268:DNA-Binding Proteins; C422952:telomerase RNA; D012313:RNA; D019098:Telomerase