Homozygous: flexed tail homozygotes can be identified hematologically as early as embryonic day 13 and are detectably paler than normal by embryonic day 16, with most paler than normal by embryonic day 15. Homozygotes are small at birth and have a transitory siderocytic hypochromic anemia due to defective heme synthesis in fetal but not adult reticulocytes. Fetal erythrocytes have more alpha hemoglobin synthesis than beta hemoglobin synthesis. Very high numbers of siderocytes are found at birth and this decreases during the first few weeks of life and stabilizes at approximately 3 weeks of age with 3% siderocytes, significantly higher than in wild-type adults. Most homozygotes have a belly spot and 1 to 5 flexures in the tail due to vertebral fusions. Vertebral fusions are also found elsewhere in the vertebral column. Fewer than expected homozygotes are generated indicating prenatal death and the postnatal death rate is approximately 4 times normal. A small minority of homozygotes have been found to have embryonic neural tube defects or a dorsal enlargement of the head.
Heterozygous: no observed phenotype
Kamenoff RJ Effects of the flexed-tailed gene on the development of the house mouse. J Morphol 1935 58 117-155
Fleming MD, Campagna DR, Haslett JN, Trenor CC 3rd, Andrews NC. A mutation in a mitochondrial transmembrane protein is responsible for the pleiotropic hematological and skeletal phenotype of flexed-tail (f/f) mice. Genes Dev. 2001 Mar 15;15(6):652-7. (Medline PMID: 11274051).
Hegde S, Lenox LE, Lariviere A, Porayette P, Perry JM, Yon M, Paulson RF. An intronic sequence mutated in flexed-tail mice regulates splicing of Smad5. Mamm Genome. 2007 Dec;18(12):852-60. Epub 2007 Nov 30. (Medline PMID: 18060457).
(see phenotype description above)
Backcross/intercross scheme. Homozygous mutants are backcrossed to 129S6 to generate the next (N) obligate hets, then intercrossed to create Sfxn1-/Sfxn1- N(x)F1's.
|Viability and Fertility:||Female||Male||Comments|
|Homozygotes are viable:||Reduced||Reduced|
|Homozygotes are fertile:||Yes||Yes|
|Heterozygotes are fertile:||Yes||Yes|
|Age Reproductive Decline:||6 months||12 months|
Distribution of this strain requires submission of the MMRRC Conditions of Use (COU). A link to the COU web form will be provided via email after an order has been placed; the form should be completed then or the email forwarded to your institutional official for completion.
The donor or their institution limits the distribution to non-profit institutions only.
Additional charges may apply for any special requests. Shipping costs are in addition to the basic distribution/resuscitation fees. Information on shipping costs and any additional charges will be provided by the supplying MMRRC facility.
|MMRRC Item #||Description||Distribution Fee / Unit (US $)
*Shipping & Handling not included*
|036656-JAX-SPERM||Cryo-preserved spermatozoa||$437.00 / Non-Profit||Aliquot||Approximate quantity3|
|036656-JAX-RESUS||Litter recovered from cryo-archive||$2,022.00 / Non-Profit||Litter||Recovered litter4; additional fees for any special requests.|
|Cryopreserved material may be available upon request, please inquire to firstname.lastname@example.org for more information.|
1 The distribution fee covers the expense of rederiving mice from a live mouse; you will receive the resulting litter. The litter will contain at minimum one mutant carrier; the actual number of animals and the gender and genotype ratios will vary. (Typically, multiple breeder pairs can be established from the recovered litter.) Prior to shipment, the MMRRC will provide information about the animals recovered. If you anticipate or find that you need to request specific genotypes, genders or quantities of mice in excess of what is likely from a resuscitated litter, you may discuss available options and pricing with the supplying MMRRC facility.
2 An aliquot contains a sufficient number of embryos (in one or more vials or straws and based on the transfer success rate of the MMRRC facility) to transfer into one to three recipients. The MMRRC makes no guarantee concerning embryo transfer success experienced in the recipient investigator's laboratory. Neither gender nor genotype ratios are guaranteed.
3 An aliquot is one straw or vial with sufficient sperm to recover at least one litter of mice, as per provided protocols, when performed at the MMRRC facility. The MMRRC makes no guarantee concerning the success of these procedures when performed outside the MMRRC facilities.
4 The distribution fee covers the expense of resuscitating mice from the cryo-archive; you will receive the resulting litter. The litter will contain at minimum one mutant carrier; the actual number of animals and the gender and genotype ratios will vary. (Typically, multiple breeder pairs can be established from the recovered litter.) Prior to shipment, the MMRRC will provide information about the animals recovered. If you anticipate or find that you need to request specific genotypes, genders or quantities of mice in excess of what is likely from a resuscitated litter, you may discuss available options and pricing with the supplying MMRRC facility.