Fig. 1: The hmTert gene and its expression in mice.

a Genomic maps of hTERT, mTert, and hmTert loci. Arrows indicate the directions of transcription. Vertical lines are exons; black and dark grey regions represent repetitive sequences, TEs, and VNTRs, respectively. Human and mouse 5’IR and introns 2 & 6 are labeled in blue and red, respectively. b Telomerase expression in tissues from Tert^+/- and Tert^h/- littermates. Telomerase activities were determined by TRAP assay. 0.5 µg protein extracts from 4-month-old mice were used except for thymus (0.12 µg). +, h, and - refer to mTert, hmTert, and mTert-KO alleles, respectively. Organs from at least three different mice were examined and data from one representative mouse are shown here. c The expression of Tert mRNAs in adult mice. Tissues were collected from 4-month-old Tert^h/+ mice. hmTert and mTert mRNAs were distinguished by using primers overlapping with the silent mutations in exon 2 of the hmTert allele. P values, two tailed student’s t test, are shown. d hTERT mRNA expression in human tissues. Tert/TERT mRNA data were determined by qRT-PCR assay, normalized to 18S rRNA, and compared to those in Tert^h/+ ESCs or human ESC H1 cells (1.0). For c, d means and standard deviations (±SDs) of three technical repeats are shown. Repeated experiments showed similar results. Source data for panels b–d are provided as Source Data files.