B6;129-Sfrp2^tm1.1Brle/J

Stock number: 018832
Research areas: Developmental Biology Research

Description

Homozygous Sfrp2 (secreted frizzled-related protein 2) mutant mice show a very mild skeletal phenotype affecting distal portions of the limbs (autopods) with shortening of metacarpals/metatarsals and all phalangeal elements. In addition there is soft-tissue syndactyly in the hind limbs between the 3rd and 4th digits (monolateral or bilateral).

Detailed description

These Sfrp2 (secreted frizzled-related protein 2) mutant mice carry a knockout allele that is useful in delineating the role of the gene in embryonic and skeletal development.

Homozygous animals are undistinguishable from their wild-type littermates at birth and exhibit normal patterning of mesenchymal cell condensations (skeletal progenitors) with normal joint formation. They show, however, mild mesomelic (mid-segment) shortening of limbs and brachydactyly of metacarpals/metatarsals due to decreased chondrocyte proliferation. They also exhibit delayed differentiation in distal limb skeletal elements, and hindlimb soft-tissue syndactyly between the 3rd and 4th digits (monolateral or bilateral) due to a lack of interdigital mesenchyme regression.

Homozygotes are viable and fertile and have a normal lifespan. Northern blot of total RNA from whole embryos at E15.5 demonstrates the absence of transcript expression from the mutant allele.

Development

Exons 1 and 2 were replaced by a loxP-flanked TK-neomycin cassette in AB2.2 129S7/SvEvBrd-Hprt1⁺-derived embryonic stem (ES) cells. Recombinant ES cell clones were further transfected with Cre-recombinase and the floxed cassette was removed. Only exon 3 of the gene remains. The donating investigator reported that chimeric males were crossed with a 129 inbred female to initiate the line. Upon arrival, mutant mice were bred to C57BL/6J inbred mice (Stock No. 000664) to establish the colony.

Allele

Symbol: Sfrp2^tm1.1Brle
Name: targeted mutation 1.1, Brendan Lee
MGI accession ID: MGI:5431901
Generation method: Targeted
Attributes: Null/Knockout
Marker symbol: Sfrp2
Marker name: secreted frizzled-related protein 2
Chromosome: 3
Strain of origin: 129S7/SvEvBrd-Hprt^b-m2
Molecular note: Exons 1 and 2 were replaced by a loxP-flanked TK-neomycin cassette. Cre-mediated recombination removed the neo cassette. Northern blot analysis confirmed the absence of transcript expression.