| Primary Identifier | MGI:1856339 | Allele Type | Transgenic |
| Gene | Fmn1 | Inheritance Mode | Recessive |
| Strain of Origin | (C57BL/6 x SJL)F2 | Is Recombinase | false |
| Is Wild Type | false |
| description | On a genetic background that involves C57BL/6 and SJL, homozygous transgenic mice display skeletal malformations including oligodactyly and partial fusions of the radius and ulna, tibia and fibula, carpals, metacarpals, tarsals, and metatarsals. The axial skeleton and skull appear unaffected. Unilateral renal aplasia is found in some of these mice. Interestingly, although the total length of the gene is probably greater than 200 kb, both transgenic insertions (Fmn1ld-TgHD and Fmn1ld-TgBri137) and the chromosomal rearrangement (Fmn1ld-Is(17;In2)1Gso) have occurred within the same 11 kb region (J:1741). Morphological effects of these gross chromosomal changes within this gene resemble those of the Grem1ld and Grem1ld-J mutations. To evaluate protein isoforms expressed in the various mutants, five isoform sets of the protein transcribed from cDNA sequences were used. The absence of isoform IV in Fmn1ld-TgHD homozygous cells made an assay for endogenous formin possible. This was used to show absence of isoform IV in homozygotes for Fmnld-TgBri137. |
| molecularNote | A 3.6 kb transgene replaced a large genomic segment (at least 36 kb) including exons 20-22, and disrupted a regulatory element that affects the expression of the downstream Grem1 gene. The deletion overlaps an 11 kb interval involved in two other limb deformity alleles: the Fmn1ld-TgHD insertion/deletion and the Fmn1ld-Is(17;In2)1Gso chromosomal rearrangement. This mutation was determined by complementation analyses to be allelic to Fmn1ld-TgHD, Grem1ld, and Grem1ld-J. The transgene contains 1.1 kb of 5' flanking sequence from the rat myelin protein zero gene (Mpz) fused to a mutant simian virus 40 early region sequence (tsA-1609). Ribonuclease protection assays suggest that isoform IV transcripts produced by the 3' region of this allele are disrupted. No differences were detected between mutant and wild-type transcripts produced by the 5' and central regions of the gene. |
