Phenotypes associated with this allele

• Allele Symbol: Tert^tm1Leah
• Allele Name: targeted mutation 1, Lea Harrington
• Allele ID: MGI:3044918
• Summary: 5 genotypes

Jump to	Allelic Composition	Genetic Background	Genotype ID
hm1	Tert^tm1Leah/Tert^tm1Leah	involves: 129P2/OlaHsd * C57BL/6J	MGI:3044924
ht2	Tert^tm1Leah/Tert^+	involves: 129P2/OlaHsd * C57BL/6J	MGI:3841482
cx3	Fancc^tm1Mab/Fancc^tm1Mab Tert^tm1Leah/Tert^tm1Leah	involves: 129P2/OlaHsd * 129S1/Sv * 129X1/SvJ * C57BL/6	MGI:4943735
cx4	Pinx1^tm1.1Kplu/Pinx1^+ Tert^tm1Leah/Tert^tm1Leah	involves: 129P2/OlaHsd * 129S7/SvEvBrd * C57BL/6 * FVB/N	MGI:5300686
cx5	Pot1a^em1Blas/Pot1a^em1Blas Tert^tm1Leah/Tert^tm1Leah	involves: 129P2/OlaHsd * C57BL/6J * C57BL/6NCrl	MGI:8352301

Genotype
MGI:3044924

hm1

• Allelic Composition: Tert^tm1Leah/Tert^tm1Leah
• Genetic Background: involves: 129P2/OlaHsd * C57BL/6J

• ♀: phenotype observed in females
• ♂: phenotype observed in males
• N: normal phenotype

cellular

aneuploidy ( J:90866 )

• late passages of homozygous mutant ES cells display increased aneuploidy relative to wild-type ES cells

abnormal telomere length ( J:90866 )

• although homozygotes are viable and overtly normal for at least 4 generations and splenocytes and thymocytes derived from first generation (G1) homozygotes display a similar telomere signal intensity as wild-type G1 littermates by flow-FISH analysis, cells from G2 homozygotes show a significant reduction in telomere length relative to wild-type and G1 homozygotes

• in addition, late passages (P25 and P50) but not early passages (P1) of homozygous mutant ES cells show a modest reduction in telomeric restriction fragment (TRF) length by pulsed-field gel electrophoresis; not observed in early or late passages of wild-type ES cells

decreased telomere length ( J:375765 )

abnormal intracellular organelle physiology ( J:375765 )

• higher DNA damage burden is seen in the intestine of G3 mice

chromosomal instability ( J:90866 )

• late passages (P50) of homozygous mutant ES cells show decreased telomere signal intensity at some chromosome ends, as shown by FISH analysis on metaphase spreads

• only late passages (P50) of homozygous mutant ES cells (~300 population doublings) show a significant increase in end-to-end chromosome fusions

• however, mitogen-stimulated cells from spleen of G1 and G2 homozygous mutant mice do not display any increase in chromosomal aberrations relative to wild-type littermates, indicating that end-to-end fusions appear only in later generations

digestive/alimentary system

abnormal intestine morphology ( J:375765 )

• higher DNA damage burden is seen in the intestine of G3 mice

• G3 mice show decreased levels of proliferation in the intestine

respiratory system

abnormal lung morphology ( J:375765 )

• G3 mice show higher incidence of alpha-smooth muscle actin (SMA) in the lung, indicating higher incidence of activated myoblasts

Genotype
MGI:3841482

ht2

• Allelic Composition: Tert^tm1Leah/Tert⁺
• Genetic Background: involves: 129P2/OlaHsd * C57BL/6J

cellular

aneuploidy ( J:90866 )

• late passages of heterozygous mutant ES cells display increased aneuploidy relative to wild-type ES cells

abnormal telomere length ( J:90866 )

• late passages (P25 and P50) but not early passages (P1) of heterozygous mutant ES cells show a modest reduction in telomeric restriction fragment (TRF) length by pulsed-field gel electrophoresis; not observed in early or late passages of wild-type ES cells

• P50 but not P1 heterozygous mutant ES cells show decreased telomere signal intensity at some chromosome ends, as shown by FISH analysis on metaphase spreads

• however, no end-to-end chromosomal fusions are detected in P50 heterozygous mutant ES cells, despite the presence of shortened telomeres

Genotype
MGI:4943735

cx3

• Allelic Composition: Fancc^tm1Mab/Fancc^tm1Mab; Tert^tm1Leah/Tert^tm1Leah
• Genetic Background: involves: 129P2/OlaHsd * 129S1/Sv * 129X1/SvJ * C57BL/6

cellular

abnormal cell physiology ( J:157096 )

• late generation mice exhibit increased short telomere-initiated telomere sister chromatid exchange compared to in cells from Tert^tm1Leah homozygotes

Genotype
MGI:5300686

cx4

• Allelic Composition: Pinx1^tm1.1Kplu/Pinx1⁺; Tert^tm1Leah/Tert^tm1Leah
• Genetic Background: involves: 129P2/OlaHsd * 129S7/SvEvBrd * C57BL/6 * FVB/N

Telomere elongation and anaphase bridges are prevented in Pinx1^tm1.1Kplu/Pinx1⁺ Tert^tm1Leah/Tert^tm1Leah mice

cellular

cellular phenotype ( J:171997 )

N • double mutants do not exhibit the telomere lengthening, anaphase bridges, lagging chromosomes or aneuploidy that is seen in single Pinx1 heterozygotes

Genotype
MGI:8352301

cx5

• Allelic Composition: Pot1a^em1Blas/Pot1a^em1Blas; Tert^tm1Leah/Tert^tm1Leah
• Genetic Background: involves: 129P2/OlaHsd * C57BL/6J * C57BL/6NCrl

cellular

decreased telomere length ( J:375765 )

• MEFs exhibit telomere shortening as well as increased frequency of short telomeres and a decrease in the frequency of long telomeres

• mice show shorter telomeres in the lung, liver, intestine, and peripheral blood mononuclear cells but no additive telomere shortening is seen

abnormal intracellular organelle physiology ( J:375765 )

• MEFs from the first mouse generation (G1) exhibit higher DNA damage

• the increase in cells with telomere damage-induced foci is to a similar extent as in each individual homozygote, but no additional additive damage is seen

reproductive system

decreased litter size ( J:375765 )

• a reduction in litter size is seen from intercrosses of G1-G2-G3 homozygous mice