B6;129S1-Diaph1^tm1Asal/J

Stock number: 030411
Product name: Drf1- , mDia1- , diap1-
Research areas: Cell Biology Research, Developmental Biology Research, Immunology, Inflammation and Autoimmunity Research, Internal/Organ Research, Neurobiology Research, Research Tools

Description

Diaph1 knock-in/knock-out allele (also called Drf1- , mDia1- or diap1-) was designed to both abolish Diaph1 gene function and express a fusion transcript encoding DRF1 amino acids 1-105 fused to EGFP. EGFP fluorescence is observed in cells that normally express DRF1. These mice may be useful in studying cytoskeleton, cell morphology, T cell polarization/migration/trafficking, immune responses, myeloproliferative syndrome (MPS) and myelodysplastic syndromes (MDS), microcephaly and hearing loss.

Detailed description

Diaphanous related formin 1 (Diaph1 ; Drf1 or mDia1) is a member of the diaphanous-related formin family of Rho effector proteins. Upon the activation of GTP-bound Rho, DRF1 generates linear actin filaments in the maintenance of polarity during adhesion, migration, and division in immune cells and neuroepithelial cells, and in driving tangential migration of cortical interneurons.

The Diaph1 knock-in/knock-out allele (also called Drf1- , mDia1- or diap1-) has EGFP replacing parts of exons 2 and 6, and all of exons 3-5 of the Diaph1 locus. This abolishes endogenous gene function and results in the Diaph1 promoter/enhancer regions directing expression of a fusion transcript encoding DRF1 amino acids 1-105 fused to EGFP. Immunoblotting shows the Drf1- allele confers loss of DRF1 protein expression. The donating investigator reports that heterozygous (Drf1^+/-) mice exhibit EGFP fluorescence in cells that normally express DRF1.

Unless stated otherwise, the following is for Drf1- mice on a C57BL/6;129 mixed genetic background.
At birth, both heterozygotes and homozygotes (Drf1^-/-) are developmentally and morphologically indistinguishable from their wildtype littermates. Both Drf1^+/- and Drf1^-/- develop age-dependent myeloproliferative defects. Homozygous onset is ~300 days of age with splenomegaly, fibrotic and hypercellular bone marrow, extramedullary hematopoiesis in both spleen and liver, and the presence of immature myeloid progenitor cells with high nucleus-to cytoplasm ratios - all characteristics of human myeloproliferative syndrome (MPS) and myelodysplastic syndromes (MDS). Heterozygotes are less severely affected with later onset (~450 days of age. [Peng et al. 2007 Cancer Res 67:7565]
Additionally, Drf1^-/- mice develop lymphopenia characterized by diminished T cell populations in lymphoid tissues. DRF1-deficient T cells exhibit defects in adhesion, migration and ruffling. [Eisenmann et al. 2007 J Biol Chem 282:25152]
Furthermore, Drf1^-/- coronal brain sections at early and postnatal stages show unilateral ventricular enlargement - indicating that this mutant mouse shows both important similarities as well as differences with a human DIAPH1 mutation that causes microcephaly. [Ercan-Sencicek et al. 2015 Eur J Hum Genet 23:165]
Of note, when maintained on a C57BL/6 genetic background, DRF1-deficiency is associated with defective T cell polarization/migration and attenuated T cell-dependent immune responses. [Dong et al. 2013 PLoS ONE 8:e80500]

Heterozygous mice of both sexes are viable and fertile up to one year of age. Homozygotes are subfertile. The donating investigator maintains their colony by breeding heterozygous females with homozygous males.

Development

The Diaph1 knock-in/knock-out allele (also called Drf1- , mDia1- or diap1-) was created in the laboratory of Dr. Arthur S. Alberts (Van Andel Research Institute). A targeting vector was designed to replace parts of exons 2 and 6, and all of exons 3-5 of the diaphanous related formin 1 locus (Diaph1 ; Drf1 or mDia1) on chromosome 18 with an enhanced green fluorescent protein (EGFP) and a PGK-neomycin-resistance cassette. The construct was electroporated into 129S1/Sv-Oca2⁺ Tyr⁺ Kitl⁺-derived CJ7 embryonic stem (ES) cells. The donating investigator reports correctly targeted ES cells were injected into recipient blastocysts, and chimeric animals were bred with 129S1/SvImJ for germline transmission. At some point, a breeding with C57BL/6J occurred. The Drf1- mutant colony was maintained on a C57BL/6J;129S1 mixed genetic background prior to sending heterozygous males with black coat color to The Jackson Laboratory Repository in 2017. Upon arrival, sperm was cryopreserved. To establish our live colony, an aliquot of frozen sperm was used to fertilize C57BL/6J oocytes (Stock No. 000664).

Allele

Symbol: Diaph1^tm1Asal
Name: targeted mutation 1, Arthur S Alberts
MGI accession ID: MGI:3722153
Generation method: Targeted
Attributes: Null/Knockout
Synonyms: Drf1^-; mDia1^-
Marker symbol: Diaph1
Marker name: diaphanous related formin 1
Marker synonyms: D18Wsu154e; DFNA1; DIA1; Diap1; Drf1; hDIA1; LFHL1; mDIA1; p140mDia; SCBMS
Chromosome: 18
Strain of origin: 129S1/Sv-Oca2⁺ Tyr⁺ Kitl⁺
Expressed genes: GFP,Green Fluorescent Protein,
Site of expression: EGFP fluorescence in expressed in cells that normally express Diaph1.
Molecular note: The insertion of an EGFP-PGK-neo replaced parts of exons 2 and 6, and all of exons 3-5.
General note: Phenotypic Similarity to Human Syndrome: Myeloproliferative syndrome and Myelodysplastic syndrome (J:124643, J:214460)