STOCK Tg(Hoxa5-cre)447BLjea/MsfdJ

Stock number: 038433
Product name: Hoxa5/Cre
Strain synonyms: B6;CBA-Tg(Hoxa5-cre)447BLjea/MsfdJ
Research areas: Developmental Biology Research, Internal/Organ Research, Research Tools

Description

Hoxa5/Cre transgenic mice express an IRES-eGFPCre fusion protein under the control of the murine Hoxa5 promoter. They may be useful for site-specific recombination in subsets of Hoxa5 expressing tissues when studying the specification of axial identity in the developing embryo.

Detailed description

Hoxa5/Cre transgenic mice express an IRES-eGFPCre fusion protein under the control of the murine homeobox A5 (Hoxa5) promoter. Hoxa5 encodes a DNA-binding transcription factor which may regulate gene expression, morphogenesis, and differentiation. It is involved in providing cells with specific positional identities on the anterior-posterior axis. When crossed with a strain containing a loxP site-flanked sequences, Cre-mediated recombination will result in deletion of the floxed sequences in the cre-expressing cells of the offspring. EGFP is detectable by direct fluorescence and immunostaining.

Hemizygous mice are viable and fertile, it is unknown if homozygous mice are viable and fertile (June 2023).

Development

A 14.5 kb Hoxa5/Cre transgenic construct was designed to contain an internal ribosome entry site (IRES) and an enhanced green fluorescent protein sequence (eGFP) fused to a Cre recombinase coding sequence (IRES-eGFPCre) under the control of the murine homeobox A5 (Hoxa5) promoter. The transgene also included an enhancer targeting Hoxa5 lung and gut developmental expression. This transgene was introduced into (C57BL/6 x CBA)F1 donor oocytes and resulting Hoxa5/Cre offspring, from founder line 447 carrying 6 copies of the transgene, were maintained on a mixed C57BL/6;CBA genetic background. Upon arrival at The Jackson Laboratory, sperm was cryopreserved. To establish a live colony, an aliquot of frozen sperm was used to fertilize B6CBAF1/J oocytes (Stock No. 100011).



In 2024, a 48 SNP (single nucleotide polymorphism) panel analysis, with 43 markers covering all 19 chromosomes and the X chromosome, as well as 5 markers that distinguish between the C57BL/6J and C57BL/6N substrains, was performed on the rederived living colony at The Jackson Laboratory Repository. Four of the 43 markers throughout the genome were segregating with an unknown source. These data suggest the mice sent to The Jackson Laboratory Repository were on a mixed genetic background.

Allele

Symbol: Tg(Hoxa5-cre)447BLjea
Name: transgene insertion 447B, Lucie Jeannotte
MGI accession ID: MGI:5518947
Generation method: Transgenic
Attributes: Recombinase-expressing
Synonyms: Tg(14.5kb Hoxa5-cre)Ljea
Marker symbol: Tg(Hoxa5-cre)447BLjea
Marker name: transgene insertion 447B, Lucie Jeannotte
Chromosome: UN
Strain of origin: (C57BL/6 x CBA)F1
Molecular note: A 5 kb genomic fragment of Hoxa5 (containing the temporal (T) control region, the brachial spinal cord (BSC) enhancer, proximal Hoxa5 promoter, both exons and the intron of Hoxa5) drives cre epxression in this transgene. An IRES-EGFPcre cassette was inserted into exon 1 of Hoxa5 downstream of the translation initiation codon. A 2.1 kb fragment containing the mesodermal (MES) enhancer and an additional 7.4-kb of downstream sequences including an enhancer driving lung and gut (L/G) expression were added at the 3' end of the construct to produce the 14.5 Hoxa5/Cre transgene. Eight founder lines were obtained and line 447B was established. This line has 6 copies of the transgene.