Flexed tail homozygotes can be identified hematologically as earlyas 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 wildtype 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 ...
This strain is homozygous for f.
Flexed tail homozygotes can be identified hematologically as earlyas 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 wildtype 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.
The FL/1Re inbred strain, homozygous for f and wildtype for Kit, was made from a female WB/Re heterozygous for KitW bred to a male heterozygous for f from a partially inbred stock derived from crosses between C3H/J and Snell?s WA linkage-testing stock. The integrated FL/1Re congenic strain, segregating for both KitW and f, was derived by repeated backcross-intercross to the developing FL/Re inbred. To generate this FL/1Re segregating congenic a female from the F1 generation of FL/Re heterozygous for KitW and homozygous for f was backcrossed to a WC/Re inbred wildtype for both Kit and f and a Kit wildtype f heterozygous offspring was bred to the F2 generation of the incipient FL/1Re inbred (Russell and McFarland, 1966). This strategy of maintenance, backcrossing KitW carriers to f/f of the FL/1Re homozygous inbred, was maintained for several decades, with this strain reaching generation N58 in 1974, and in 1980 embryos were generated for cryopreservation from +/+ f/f FL/1Re inbred females at generation F79 and KitW/+ f/+ and KitW/+ +/+ congenic males at generation N81.
|Allele Name||dominant spotting|
|Gene Symbol and Name||Kit, kit oncogene|
|Gene Synonym(s)||Bs; C-Kit; CD117; Dominant white spotting; Fdc; Gsfsco1; Gsfsco1; Gsfsco5; Gsfsco5; Gsfsow3; Gsfsow3; PBT; SCFR; SCO1; SCO5; SOW3; Ssm; Steel Factor Receptor; Tr-kit; W; belly-spot; belly-spot; c-KIT; dominant spotting; gsf spotted coat 1; gsf spotted coat 5; phenotype like Sl or W 3; spotted sterile male|
|Strain of Origin||old mutant of the mouse fancy|
|General Note||This is an old mutant of the mouse fancy. KitW mutants are a potential model for human inherited pure red cell anemia, called Diamond-Blackfan anemia (OMIM 205900), but mouse mutants do not respond to corticosteroid treatment as do human patients. Thus, the mechanism of anemia causation in the two conditions must be different (J:14286).|
|Molecular Note||A guanosine to adenosine substitution at the first nucleotide at the 5' boundary of the intron following the transmembrane exon results in two different aberrantly spliced transcripts putatively expressed in a tissue specific manner. A deletion of 107 bp was found in transcripts from mast cells of mutant mice. A deletion of 234 was found in transcripts from brain or bone marrow cells. The GT to AT point mutation probably disrupted a splice donor site, thereby causing exon skipping. The 107 bp deletion could have resulted from skipping of a transmembrane region exon and the 234 bp deletion from skipping 3 exons. The 107 bp deletion would generate a stop codon 12 bp downstream because of a frame shift, whereas the larger deletion would still be in frame. Northern blot analysis indicated that mast cells from mutants have only 31-37% of the transcripts as mast cells derived from normal bone marrow, suggesting that the mutation may reduce efficiency and authenticity of transcription and splicing.|
|Allele Name||flexed tail|
|Gene Symbol and Name||f, flexed-tail|
|Strain of Origin||Not Specified|
|General Note|| |
The flexed-tail mutation appeared in a stock maintained by Dr. H.R. Hunt at Michigan State College (J:12951). Homozygotes are small at birth and have a transitory hypochromic, microcytic anemia characterized by a large number of siderocytes containing non-heme iron granules. Most homozygotes also have flexed tail and a belly spot, but these are not constant manifestations of the mutant. Because of the anemia there is probably greater postnatal mortality among f/f than among normal mice (J:14979).
The anemia begins on the 12th day of embryonic life when the liver first starts to produce blood cells (J:14979). It is most intense at 15 days of gestation and still severe at birth, but by 2 weeks of age has disappeared. Although adults have normal blood values, their response to hemopoietic stress is defective (J:5439, J:27511).
The results of numerous studies have led to the conclusion that the prenatal deficiency in number of erythrocytes and the defective response of adult erythropoietic cells are due to a delay in maturation of already committed erythroid stem cells, and that earlier uncommitted precursors are unaffected by f (J:5439, J:5654, J:5582).
An additional effect of f in homozygotes is defective heme synthesis, which occurs in fetal reticulocytes but not in adult reticulocytes nor in erythroblasts at earlier stages of maturation. In fetal reticulocytes there is normal uptake of iron but poor incorporation into hemoglobin (J:5439), probably as a result of reduced activity ofdelta-aminolevulinate synthetase and dehydratase (J:5591).
Fetal erythrocytes of f/f mice have more alpha than beta globin chains. In both f/f and wild-type fetal erythrocytes there is more alpha- than beta-chain mRNA; probably some regulatory mechanism bringing about equal alpha- and beta-chain synthesis exists in wild-type mice but is defective in f/f (J:5827, J:30711).
The tail abnormalities are first noticeable on the 14th day of gestation as abnormal differentiation of the intervertebral discs (J:13090). The possibility that abnormal heme synthesis could cause the tail and pigment defects in f/f mice has been discussed (J:5591).
It was suggested that flexed-tail might be a mutation in the mouse homolog Fancc of the gene defective in human Fanconi anemia, complementation group C, but no mutation in the Fancc gene or abnormalities in Fancc mRNA have been detected in f/f mutants (J:13598). Also, flexed-tail mice are not susceptible to increases in chromosomal aberrations induced by mitomycin C, a characteristic of Fancc mutant mice (J:35839).
This allele arose on a genetically undefined stock in 1927 and was subsequently transferred onto several genetic backgrounds to create the congenic and recombinant inbred lines Je/Le-f/f, FL1/ReJ, WB/ReJ-f/f and C57BL/6J-f/f. The phenotypes listed above might be associated with any of these strains; in most cases it was not specified.
|Molecular Note||Note that two conflicting reports (J:68377 and J:98445/J:128616) state that the underlying genetic defect in the flexed tail mouse is either in the Sfxn1 or the Smad5 gene.|
|Mutations Made By|| |
Mark Fleming, Children's Hospital Boston
The average number of mice provided from recovery of our cryopreserved strains is 10. The total number of animals provided,
their gender and genotype will vary. We will fulfill your order by providing at least two pair of mice, at least one animal of
each pair carrying the mutation of interest. Please inquire if larger numbers of animals with specific genotype and genders
are needed. Animals typically ship between 10 and 14 weeks from the date of your order. If a second cryorecovery is needed in
order to provide the minimum number of animals, animals will ship within 25 weeks.
The genotypes of animals provided may not reflect the mating scheme utilized by The Jackson Laboratory prior to cryopreservation, or that discussed in the strain description. Please inquire about possible genotypes which will be recovered for this specific strain. The Jackson Laboratory cannot guarantee the reproductive success of mice shipped to your facility. If the mice are lost after the first three days (post-arrival) or do not produce progeny at your facility, a new order and fee will be necessary.
Cryorecovery to establish a Dedicated Supply for greater quantities of mice. Mice recovered can be used to establish a dedicated colony to contractually supply you mice according to your requirements. Price by quotation.
Terms are granted by individual review and stated on the customer invoice(s) and account statement. These transactions are payable in U.S. currency within the granted terms. Payment for services, products, shipping containers, and shipping costs that are rendered are expected within the payment terms indicated on the invoice or stated by contract. Invoices and account balances in arrears of stated terms may result in The Jackson Laboratory pursuing collection activities including but not limited to outside agencies and court filings.
The Jackson Laboratory has rigorous genetic quality control and mutant gene genotyping programs to ensure the genetic background of JAX® Mice strains as well as the genotypes of strains with identified molecular mutations. JAX® Mice strains are only made available to researchers after meeting our standards. However, the phenotype of each strain may not be fully characterized and/or captured in the strain data sheets. Therefore, we cannot guarantee a strain's phenotype will meet all expectations. To ensure that JAX® Mice will meet the needs of individual research projects or when requesting a strain that is new to your research, we suggest ordering and performing tests on a small number of mice to determine suitability for your particular project.
"MICE" means mouse strains, their progeny derived by inbreeding or crossbreeding, unmodified derivatives from mouse strains or their progeny supplied by The Jackson Laboratory ("JACKSON"). "PRODUCT(S)" means biological materials supplied by JACKSON, and their derivatives. "SERVICES" means projects conducted by JACKSON for other parties that may include but are not limited to the use of MICE or PRODUCTS. "RECIPIENT" means each recipient of MICE, PRODUCTS, or SERVICES provided by JACKSON including each institution, its employees and other researchers under its control. MICE or PRODUCTS shall not be: (i) used for any purpose other than internal research, (ii) sold or otherwise provided to any third party for any use, or (iii) provided to any agent or other third party to provide breeding or other services. Acceptance of MICE, PRODUCTS or SERVICES from JACKSON shall be deemed as agreement by RECIPIENT to these conditions, and departure from these conditions requires JACKSON’s prior written authorization.
MICE, PRODUCTS AND SERVICES ARE PROVIDED "AS IS". JACKSON EXTENDS NO WARRANTIES OF ANY KIND, EITHER EXPRESS, IMPLIED, OR STATUTORY, WITH RESPECT TO MICE, PRODUCTS OR SERVICES, INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, OR ANY WARRANTY OF NON-INFRINGEMENT OF ANY PATENT, TRADEMARK, OR OTHER INTELLECTUAL PROPERTY RIGHTS.
In case of dissatisfaction for a valid reason and claimed in writing by a purchaser within ninety (90) days of receipt of, PRODUCTS or SERVICES, JACKSON will, at its option, provide credit or replacement for the PRODUCT received or the SERVICES provided; JACKSON makes no other representations and this shall be the exclusive remedy of the purchaser. Please note specific policy for live mice.
Consistent with the requirement for a written understanding regarding animal care and use, the JACKSON Animal Care and Use Committee will review the animal care and use protocol(s) associated with any SERVICES to be performed at JACKSON, and JACKSON shall have ultimate responsibility and authority for the care of animals while on site or in JACKSON custody.
In no event shall JACKSON, its trustees, directors, officers, employees, and affiliates be liable for any causes of action or damages, including any direct, indirect, special, or consequential damages, arising out of the provision of MICE, PRODUCTS, or SERVICES, including economic damage or injury to property and lost profits, and including any damage arising from acts or negligence on the part of JACKSON, its agents or employees. Unless prohibited by law, in purchasing or receiving MICE, PRODUCTS, or SERVICES from JACKSON, purchaser or recipient, or any party claiming by or through them, expressly releases and discharges JACKSON from all such causes of action or damages, and further agrees to defend and indemnify JACKSON from any costs or damages arising out of any third party claims.
MICE, PRODUCTS or SERVICES are to be used in a safe manner and in accordance with all applicable governmental rules and regulations.
The foregoing represents the General Terms and Conditions applicable to JACKSON’s MICE, PRODUCTS or SERVICES. In addition, special terms and conditions of sale of certain MICE, PRODUCTS, or SERVICES may be set forth separately in JACKSON web pages, catalogs, price lists, contracts, and/or other documents, and these special terms and conditions shall also govern the sale of these MICE, PRODUCTS and SERVICES by JACKSON, and by its licensees and distributors.
Acceptance of delivery of MICE, PRODUCTS or SERVICES shall be deemed agreement to these terms and conditions. No purchase order or other document transmitted by purchaser or recipient that may modify the terms and conditions hereof, shall be in any way binding on JACKSON, and instead the terms and conditions set forth herein, including any special terms and conditions set forth separately, shall govern the sale of MICE, PRODUCTS or SERVICES by JACKSON.