CAST.129S1(B6)-Kif18a^gcd2/JcsMmjax

Stock number: 014535
Product name: germ cell depletion 2
Research areas: Developmental Biology Research, Reproductive Biology Research

Description

These EMS-induced mice exhibit a strain dependent sterility phenotype due to germ cell depletion. On the CAST/Ei background, homozygotes are 90% sterile. Testes have few or no developing germ cells and ovaries are small with few or no follicles. This mutant mouse strain may be useful in studies of gametogenesis.

Detailed description

Homozygotes: Mice that are homozygous for this mutation exhibit a strain dependent sterility phenotype due to germ cell depletion. On the CAST/Ei background, homozygotes are 90% sterile. Testes have few or no developing germ cells and ovaries are small with few or no follicles. The reduction in the number of germ cells is first observed in the embryonic proliferative/post-proliferative period (11.5 dpc) following germ cell migration to the embryonic gonads. On a C57BL/6J background, 37% of mice are infertile and on a mixed CAST/Ei and C57BL/6J background, an intermediate phenotype (64%) is observed. This mutant mouse strain may be useful in studies of gametogenesis.

Heterozygote: Not evaluated. The heterozygote phenotype is expected to be similar to the wild-type phenotype.

Development

The germ cell depletion 2 mutation was induced in 129S1/Sv-Oca2⁺ Tyr⁺ Kitl⁺-derived CJ7 ES cells via a 16 hour exposure to ethyl methansulfonate. Treated ES cells were injected into C57BL/6J blastocysts and the chimeras were bred with C57BL/6J males. The mutation results in a G to A transversion of the Kif18a gene, in exon 7. The mutation alters the corresponding amino acid from arginine to lysine at codon 308 (R308K). The mutation was introgressed to CAST/EiJ, and selected using the 129S1-derived flanking markers D2Mit58 and D2Mit274 at each generation. In 2008 this congenic reached generation N9F2. Males donated to the MMRRC were cryopreserved by sperm.

Please note: Because in vitro fertilization is problematic with CAST oocytes, mice recovered from cryopreservation will be generated using C57BL/6 oocytes. Recovery of the 90% sterility phenotype will require additional crosses to CAST.

Allele

Symbol: Kif18a^gcd2
Name: germ cell depletion, John Schimenti
MGI accession ID: MGI:3050507
Generation method: Chemically induced (other)
Attributes: Null/Knockout
Marker symbol: Kif18a
Marker name: kinesin family member 18A
Chromosome: 2
Strain of origin: 129S1/Sv-Oca2⁺ Tyr⁺ Kitl⁺
Molecular note: The gcd2 mutation affects the highly conserved R308 residue within the KIF18A motor domain. The gcd2 mutation is a G-to-A transition in exon 7. This is a missense mutation that changes an AGA codon to an AAA, leading to the single amino acid change, R308K. Arginine 308 is a highly conserved amino acid in the motor domain of the protein.
General note: ES cells were mutagenized using ethyl methansulfonate (EMS). Generation 3 mice on a mixed 129S1/SvImJ and C57BL/6 background were identified by examining ductus deferens sperm for defects in morphology, motility, and quantity.