B6.Cg-Tg(Tek-cre)1Ywa/J

Stock number: 008863
Product name: Tie2-Cre
Research areas: Cancer Research, Neurobiology Research, Research Tools, Sensorineural Research

Description

The Tie2-Cre (Tek-Cre) transgene has the mouse endothelial-specific receptor tyrosine kinase (Tek or Tie2) promoter directing expression of Cre recombinase. These Tek-Cre transgenic mice are a Cre-lox tool useful for deletion of floxed sequences in endothelial cells during embryogenesis and adulthood. Cre recombinase activity is also detected in reproductive tissues (endometrium, ovary, testis, epididymis), as well as extraembryonic vascular system and yolk sac.

Detailed description

Please see Development section for information regarding transgene copy number.

These Tek-Cre (Tie2-Cre) transgenic mice express Cre recombinase under the direction of the receptor tyrosine kinase Tek (Tie2) promoter/enhancer, which has been shown to provide uniform expression in endothelial cells during embryogenesis and adulthood (see additional expression information below). Mice that are hemizygous for the transgenic insert are viable, fertile, normal in size and do not display any gross physical or behavioral abnormalities. Recombinase activity results in the deletion of loxP flanked targets in vascular endothelial cells. Cre recombinase activity is also detected in reproductive tissues (endometrium, ovary, testis, epididymis), as well as extraembryonic vascular system and yolk sac.
As such, for Cre-lox experiments and to reduce the frequency of germline deletion of the floxed allele, researchers may consider maintaining the Tek-Cre transgene as hemizygous in males but not in females. Researchers are urged to monitor their Cre;floxed double mutant mice for any undesirable germline deletion of the floxed allele (e.g., genotyping tail/ear samples). Researchers may consider also maintaining a Tek-Cre colony separate from any floxed colonies.

The donating investigator's 2001 publication estimated ~2 copies of the Tek-Cre transgene integrated had been inserted randomly into the genome. In 2017, it was discovered the transgene integrated approximately 15 kB into intron 1 of the Sorcs2 gene on Chr 5 (between nucleotides 36382105 to 36382309 GRCm37/mm9 genome build) resulting in a 204 bp deletion. The insertion leads to reduced and variable expression of Sorcs2. Mice homozygous for the transgene exhibit abnormal cochlear stereociliary bundle formation on both inner and outer hair cells along the organ of Corti, decreased body weight and deafness.

If the recombinase activity pattern of this Tek-Cre allele is further characterized by the Genetic Resource Science group at The Jackson Laboratory, such findings will be reported on the Mouse Genome Informatics (MGI) Allele Detail entry. This same information may also be found searching the MGI Recombinase Activity and MGI Gene Expression + Recombinase Activity Comparison Matrix.

Development

Cre cDNA and metallothionein-1 (MT-1) polyA signal sequence was inserted between the mouse Tek (Tie2) promoter and enhancer. The transgenic cassette was injected into B6SJLF1 fertilized oocytes and backcrossed to a C57BL/6 genetic background for at least eight generations by the donating investigator.

The donating investigator's 2001 publication estimated ~2 copies of the Tek-Cre transgene integrated had been inserted randomly into the genome. In 2017, it was discovered the transgene integrated approximately 15 kB into intron 1 of the Sorcs2 gene on Chr 5 (between nucleotides 36382105 to 36382309 GRCm37/mm9 genome build) resulting in a 204 bp deletion.

Important Note regarding transgene copy number:
In 2021-2022, advanced quality control analysis performed by The Jackson Laboratory identified Stock No. 008863 hemizygous pedigrees having either ~3-4 or ~10-12 copies of the Tek-Cre transgene. Thereafter, we began to establish a pedigree of hemizygous breeders with ~3-4 Tek-Cre transgene copies [April 2022]. This will replace the distribution colony and cryopreserved stocks, but is still in progress at this time [August/September 2022]. The mice distributed from Stock No. 008863 have been verified to contain the transgene, but the transgene copy number cannot be guaranteed at this time [August/September 2022]. Please see our Genotyping Protocols section for qPCR assay.

Allele

Symbol: Tg(Tek-cre)1Ywa
Name: transgene insertion 1, Masashi Yanagisawa
MGI accession ID: MGI:2450311
Generation method: Transgenic
Attributes: Recombinase-expressing; Hypomorph
Marker symbol: Tg(Tek-cre)1Ywa
Marker name: transgene insertion 1, Masashi Yanagisawa
Chromosome: 5
Strain of origin: (C57BL/6 x SJL)F1
Expressed genes: cre,cre recombinase,bacteriophage P1
Site of expression: Uniform expression in endothelial cells during embryogenesis and adulthood. Cre recombinase activity in vascular endothelial cells, also detected in reproductive tissues (endometrium, ovary, testis, epididymis), as well as extraembryonic vascular system and yolk sac.
Molecular note: This transgene expresses Cre recombinase under the control of a mouse Tek promoter and enhancer. This promoter is active in endothelial cells. Insertion within intron 1 of Sorcs2 results in the 204 bp deletion (36382105 to 36382309 on mouse chromosome 5; GRCm37/mm9 genome build) leading to reduced and variable expression.