PMID- 11536432
OWN - NLM
STAT- MEDLINE
DCOM- 20011204
LR  - 20191105
IS  - 1526-954X (Print)
IS  - 1526-954X (Linking)
VI  - 30
IP  - 4
DP  - 2001 Aug
TI  - Bidirectional transcriptional activity of PGK-neomycin and unexpected embryonic 
      lethality in heterozygote chimeric knockout mice.
PG  - 259-63
AB  - In an effort to create a conventional knockout mouse model for multiple endocrine 
      neoplasia type 1 (MEN1), we targeted disruption of the mouse Men1 gene through 
      homologous recombination in ES cells. Men1 exons 2-4 were replaced by a 
      PGK-neomycin cassette inserted in the opposite direction of Men1 transcription 
      (Men1(MSK/+)). Unexpectedly, the Men1 conventional knockout was lethal in 
      heterozygous, chimeric animals. Analysis of embryos revealed late gestational 
      lethality with some embryos showing omphalocele. This was a very surprising 
      phenotype, given that humans and mice that are heterozygotes for loss of function 
      mutations in MEN1 are phenotypically normal except for a risk of endocrine 
      tumors. Northern analysis of Men1(MSK/+) embryonic stem cell RNA revealed the 
      presence of an abundant, novel transcript of 2.1 kb, in addition to the expected 
      wild-type transcripts of 2.7 kb and 3.1 kb. RT-PCR analysis identified this 
      aberrant transcript as arising from the antisense strand of the PGK promoter. We 
      hypothesize that this transcript is producing either a toxic effect at the RNA 
      level, or a dominant negative effect through the production of an amino-terminal 
      truncated protein product. This example serves as a cautionary reminder that 
      mouse knockouts using PGK-neo may sometimes display phenotypes that reflect more 
      than just the loss of function of the targeted gene.
FAU - Scacheri, P C
AU  - Scacheri PC
AD  - National Human Genome Research Institute, National Institute of Health, Bethesda, 
      Maryland 20892, USA.
FAU - Crabtree, J S
AU  - Crabtree JS
FAU - Novotny, E A
AU  - Novotny EA
FAU - Garrett-Beal, L
AU  - Garrett-Beal L
FAU - Chen, A
AU  - Chen A
FAU - Edgemon, K A
AU  - Edgemon KA
FAU - Marx, S J
AU  - Marx SJ
FAU - Spiegel, A M
AU  - Spiegel AM
FAU - Chandrasekharappa, S C
AU  - Chandrasekharappa SC
FAU - Collins, F S
AU  - Collins FS
LA  - eng
PT  - Journal Article
PL  - United States
TA  - Genesis
JT  - Genesis (New York, N.Y. : 2000)
JID - 100931242
RN  - 0 (MEN1 protein, human)
RN  - 0 (Neoplasm Proteins)
RN  - 0 (Proto-Oncogene Proteins)
RN  - 0 (RNA, Messenger)
RN  - I16QD7X297 (Neomycin)
SB  - IM
MH  - Animals
MH  - Blotting, Western
MH  - Chimera/genetics
MH  - Embryo Loss/*genetics
MH  - Embryo, Mammalian/metabolism
MH  - Exons/genetics
MH  - Gene Deletion
MH  - Gene Targeting/methods
MH  - Genes, Dominant/genetics
MH  - Genes, Lethal/*genetics
MH  - Genes, Reporter/genetics
MH  - Hernia, Umbilical/genetics
MH  - *Heterozygote
MH  - Mice
MH  - Mice, Knockout
MH  - Mutagenesis, Insertional/*genetics
MH  - Neomycin/biosynthesis
MH  - Neoplasm Proteins/*genetics
MH  - Phenotype
MH  - Precipitin Tests
MH  - Promoter Regions, Genetic/genetics
MH  - *Proto-Oncogene Proteins
MH  - RNA, Messenger/genetics/metabolism
MH  - Transcription, Genetic/*genetics
EDAT- 2001/09/06 10:00
MHDA- 2002/01/05 10:01
CRDT- 2001/09/06 10:00
PHST- 2001/09/06 10:00 [pubmed]
PHST- 2002/01/05 10:01 [medline]
PHST- 2001/09/06 10:00 [entrez]
AID - 10.1002/gene.1072 [pii]
AID - 10.1002/gene.1072 [doi]
PST - ppublish
SO  - Genesis. 2001 Aug;30(4):259-63. doi: 10.1002/gene.1072.