B6(Cg)-Slc6a8^tm1.2Clar/J

Stock number: 021072
Product name: CrT knockout
Research areas: Cell Biology Research, Developmental Biology Research, Neurobiology Research

Description

The ubiquitous CrT knockout allele (CrT^-) has a deletion of the exons encoding the 2nd-4th transmembrane domain of the creatine transporter gene on the X chromosome. These mice may be useful for studying creatine transport and human X-linked creatine deficiency syndrome, mental retardation, autism, and speech, language, cognitive, and memory disorders.

Detailed description

The ubiquitous CrT knockout allele (CrT^-) has a deletion of the exons encoding the 2nd-4th transmembrane domain of the creatine transporter gene on the X chromosome. Heterozygous females (CrT^+/-) are viable and fertile with no observed abnormalities. Hemizygous males (CrT^-/Y) do not breed (perhaps due to behavioral/cognitive phenotype; fertility is unknown). No homozygous females have been generated to date (January 2013). Males hemizygous for the pan deletion (CrT^-/Y) lack creatine in brain and muscle, have significant creatine reductions in other tissues (including heart and testis), and exhibit learning and memory deficits resembling human X-linked creatine deficiency syndrome.

Of note, the donating investigator also sent the CrT^flox conditional mice (floxed exons 2-4) to The Jackson Laboratory Repository as Stock No. 020642.

Development

A targeting vector was designed by Dr. Joseph F. Clark (University of Cincinnati) to insert a loxP site upstream of exon 2, and an frt-flanked neo cassette and second loxP site downstream of exon 4 of the creatine transporter gene (CrT; Slc6a8) on the X chromosome. The construct was electroporated into C57BL/6-derived embryonic stem (ES) cells. Correctly targeted ES cells were injected into recipient MF-1 blastocysts. Chimeric males were bred with C57BL/6J females to generate the conditional founder mice. To remove the frt-flanked neo cassette, mice were bred with the germline FLP deleter strain (B6;SJL-Tg(ACTFLPe)9205Dym/J; Stock No. 003800). Offspring with the CrT^flox allele (loxP site upstream of exon 1, and a single frt site and second loxP site downstream of exon 4) were obtained. The CrT^flox mice were bred to C57BL/6J wildtype mice for several generations (and the FLP transgene was removed) prior to sending to The Jackson Laboratory Repository in 2013 as Stock No. 020642. Upon arrival, some CrT^flox mice were bred to animals expressing Cre recombinase in the germline (B6.Sox2Cre; Stock No. 008454) to remove floxed exons 2-4. Offspring with the ubiquitous CrT knockout allele (CrT^-) were established. Heterozygous females were bred to C57BL/6J wildtype males to remove the Sox2Cre transgene. The CrT^- colony was then maintained by breeding heterozygous females with wildtype males from the colony or with C57BL/6J inbred males.

Allele

Symbol: Slc6a8^tm1.2Clar
Name: targeted mutation 1.2, Joseph Clark
MGI accession ID: MGI:3522510
Generation method: Targeted
Attributes: Null/Knockout
Marker symbol: Slc6a8
Marker name: solute carrier family 6 (neurotransmitter transporter, creatine), member 8
Marker synonyms: CCDS1; CHOT1; CHT1; Creat; CRT; CRT1; CRT-1; CRTR; CT1; CTR5
Chromosome: X
Strain of origin: C57BL/6
Molecular note: Cre-mediated recombination of Slc6a8^tm1.1Clar removed exons 2, 3, and 4.