B6.129S1-Snrpn^tm2.1Kaj/J

Stock number: 018395
Research areas: Developmental Biology Research, Research Tools

Description

These PWS-IC^flox6kb mice may be useful in generating conditional mutations for studying the role of Snrpn and the temporal and developmental requirements of the Prader-Willi imprinting center.

Detailed description

Mice homozygous for this PWS-IC^flox6kb allele are viable and fertile, with loxP sites flanking the 6 kb Prader-Willi Syndrome imprinting center (PWS-IC) region around exon 1 of the Snrpn gene . When bred to mice that express Cre recombinase, the resulting offspring will have this area deleted in the cre-expressing tissue(s). Because Snrpn is imprinted and only expressed from the paternal allele, breeding PWS-IC^flox6kb males with cre-expressing females is required to generate deleted offspring with the knockout phenotype. These PWS-IC^flox6kb mice be useful in studying the temporal and spatial functions of the Prader-Willi imprinting center.

When crossed to female mice carrying the Tg(CMV-cre)1Cgn allele (see Stock No. 006054), widespread Cre recombinase expression prior to implantation results in postnatal lethality.

When crossed to female mice carrying the Tg(Nes-cre)1Kln allele (see Stock No.003771), Cre recombinase expression in brain precursors cells starting at E10.5 results in a growth retardation, but is not lethal.

Development

A targeting vector was designed to insert a loxP site upstream of exon 1 followed by a loxP-flanked neomycin resistance (neo) cassette downstream of exon 1. The construct was electroporated into 129S1/Sv-derived CJ7 embryonic stem (ES) cells. Correctly targeted ES cells were transiently transfected with a cre-expressing plasmid to remove the neo selection cassette, but retain the loxP-flanked 6 kb Prader-Willi Syndrome-imprinting center (PWS-IC) region centered around exon 1. Chimeric mice crossed to C57BL/6J and offspring were backcrossed to C57BL/6J for 11 generations. Upon arrival at The Jackson Laboratory, mice were bred to C57BL/6J inbred mice (Stock No. 000664) for at least one generation to establish the colony.

Allele

Symbol: Snrpn^tm2.1Kaj
Name: targeted mutation 2.1, Karen A Johnstone
MGI accession ID: MGI:5140864
Generation method: Targeted
Attributes: Conditional ready (e.g. floxed); No functional change
Synonyms: PWS-IC^flox6kb
Marker symbol: Snrpn
Marker name: small nuclear ribonucleoprotein N
Chromosome: 7
Strain of origin: 129S1/Sv-Oca2⁺ Tyr⁺ Kitl⁺
Molecular note: A loxP site was inserted 3.7 kb upstream of exon 1. A floxed neo cassette was inserted downstream of exon 1. Cre-mediated recombination first removed the neo cassette and left the 6 kb encompassing the Prader-Willi syndrome imprinting center (PWS-IC) floxed.