PMID- 10029690
OWN - NLM
STAT- MEDLINE
DCOM- 19990312
LR  - 20190702
IS  - 0027-5107 (Print)
IS  - 0027-5107 (Linking)
VI  - 423
IP  - 1-2
DP  - 1999 Jan 25
TI  - Tk+/- mouse model for detecting in vivo mutation in an endogenous, autosomal
      gene.
PG  - 125-36
AB  - Tk+/- transgenic mice were created using an embryonic stem cell line in which one
      allele of the endogenous thymidine kinase (Tk) gene was inactivated by targeted
      homologous recombination. Breeding Tk+/- parents produced viable Tk-/- knockout
      (KO) mice. Splenic lymphocytes from KO mice were used in reconstruction
      experiments for determining the conditions necessary for recovering Tk somatic
      cell mutants from Tk+/- mice. The cloning efficiency of KO lymphocytes was not
      affected by the toxic thymidine analogues 5-bromo-2'-deoxyuridine (BrdUrd) or
      trifluorothymidine (TFT), or by BrdUrd in the presence of lymphocytes from Tk+/- 
      animals; however, it was easier to identify clones resistant to BrdUrd than to
      TFT when Tk+/- cells were present. Tk+/- mice were treated with vehicle or 100
      mg/kg of N-ethyl-N-nitrosourea (ENU), and after 4 months, the frequency of Tk
      mutant lymphocytes was measured by resistance to BrdUrd. The frequency of Tk
      mutants was 22+/-5.9x10-6 in control animals and 80+/-31x10-6 in treated mice. In
      comparison, the frequency of Hprt mutant lymphocytes, as measured by resistance
      to 6-thioguanine, was 2.0+/-1.2x10-6 in control animals and 84+/-28x10-6 in the
      ENU-treated mice. Analysis of BrdUrd-resistant lymphocyte clones derived from the
      ENU-treated animals revealed point mutations in the non-targeted Tk allele. These
      results indicate that the selection of BrdUrd-resistant lymphocytes from Tk+/-
      mice may be used for assessing in vivo mutation in an endogenous, autosomal gene.
CI  - Copyright 1999 Elsevier Science B.V.
FAU - Dobrovolsky, V N
AU  - Dobrovolsky VN
AD  - Division of Genetic and Reproductive Toxicology, HFT-120, National Center for
      Toxicological Research, 3900 NCTR Road, Jefferson, AR 72079, USA.
      vdobrovolsky@nctr.fda.gov
FAU - Casciano, D A
AU  - Casciano DA
FAU - Heflich, R H
AU  - Heflich RH
LA  - eng
PT  - Journal Article
PT  - Research Support, U.S. Gov't, Non-P.H.S.
PT  - Research Support, U.S. Gov't, P.H.S.
PL  - Netherlands
TA  - Mutat Res
JT  - Mutation research
JID - 0400763
RN  - EC 2.4.2.8 (Hypoxanthine Phosphoribosyltransferase)
RN  - EC 2.7.1.21 (Thymidine Kinase)
RN  - P8M1T4190R (Ethylnitrosourea)
SB  - IM
MH  - Animals
MH  - Crosses, Genetic
MH  - Ethylnitrosourea/toxicity
MH  - Female
MH  - Genes/*drug effects
MH  - Hypoxanthine Phosphoribosyltransferase/deficiency/genetics
MH  - Male
MH  - Mice
MH  - Mice, Inbred C57BL
MH  - Mice, Knockout
MH  - Mice, Transgenic
MH  - Models, Genetic
MH  - *Mutagenesis
MH  - Thymidine Kinase/*deficiency/*genetics
EDAT- 1999/02/25 00:00
MHDA- 1999/02/25 00:01
CRDT- 1999/02/25 00:00
PHST- 1999/02/25 00:00 [pubmed]
PHST- 1999/02/25 00:01 [medline]
PHST- 1999/02/25 00:00 [entrez]
AID - S0027-5107(98)00234-6 [pii]
AID - 10.1016/s0027-5107(98)00234-6 [doi]
PST - ppublish
SO  - Mutat Res. 1999 Jan 25;423(1-2):125-36. doi: 10.1016/s0027-5107(98)00234-6.