neoR

Homologous recombination of the targeted gene will result in neoR expression but the tk element will be lost since it was outside of the recombining DNA sequences.

The 2007 Nobel Prize in Physiology or Medicine - Advanced Information 2007

In utero gene therapy: Transfer and long term expression of the bacterial neoR gene in sheep following direct injection of retroviral vectors into pre-immune fetuses.

Fetal Stem Cell Transplantation, In Utero Stemm Cell Publications 2010

Genes targeted by homologous recombination contain the neoR element but not HSV-tk, since the latter resides outside the sequences in the targeting vector homologous to sequences in the chromosomal gene.

The 2007 Nobel Prize in Physiology or Medicine - Advanced Information 2007

In contrast, random integration of the replacement vector will introduce tk as well as neoR into the gene.

The 2007 Nobel Prize in Physiology or Medicine - Advanced Information 2007

A neomycin resistance element (neoR) is introduced into an exon of the replacement vector, which also has a thymidine kinase (HSV-tk) element at its end.

The 2007 Nobel Prize in Physiology or Medicine - Advanced Information 2007

Thomas and Capecchi [36] introduced a neomycin resistance gene into an exon of the HPRT gene in ES cells and showed that clones of transfected cells had lost HPRT but gained neoR activity.

The 2007 Nobel Prize in Physiology or Medicine - Advanced Information 2007

Screening methods select positively for neoR positive clones and discard those neoR + clones that carry HSV-tk.

The 2007 Nobel Prize in Physiology or Medicine - Advanced Information 2007

In contrast, random integration of the vector results in introduction of HSV-tk as well as neoR.

The 2007 Nobel Prize in Physiology or Medicine - Advanced Information 2007

The insertion of the neoR cassette into intron 2 of the

Journal of Biological Chemistry current issue 2008