Exon 3 of the Sec24c gene is flanked by loxP sites in this conditional Sec24c-FL mutant strain. These mice are useful in studies of embryonic development and endoplasmic reticulem (ER)-Golgi vesicular trafficking.
David Ginsburg, University of Michigan
SEC24 proteins are responsible for selectively recruiting cargo proteins from the endoplasmic reticulum (ER) into COPII vesicles that mediate transport to the Golgi. Sec24c (Sec24 related gene family, member C (S. cerevisiae)) is one of four mammalian Sec24 paralogs which are highly conserved at the C-terminus and variable in the N-terminal region. Mice completely lacking SEC24C die around embryonic day 7.
Exon 3 of the Sec24c gene is flanked by loxP sites in this conditional mutant strain. Heterozygous and homozygous Sec24c-FL mice are healthy, appear normal and are fertile. Cre excision of the floxed segment results in a frameshift mutation and early stop in exon 4, producing a null allele (see Stock No. 024868).
Progeny derived from crosses with a smooth muscle cell-specific Cre strain (SM22-Cre, see Stock No. 04746) do not have any grossly apparent abnormalities and are able to carry litters to term. Pups derived from crosses with albumin-Cre (hepatocyte-specific , see Stock No. 003574) and villin-cre (intestinal-epithelial-specific, see Stock No. 004586), show normal plasma cholesterol and triglyceride levels when on a high fat diet.
Embryonic stem (ES) cell clone EPD0241-2-A11 (EUCOMM ID: 32981) was created by the Wellcome Trust Sanger Institute as part of the Knockout Mouse Project (KOMP). The original gene trapped allele of Sec24c incorporated an FRT-En2 splice acceptor (SA)-IRES-lacZ-SV40 polyadenylation signal (pA)-loxP-PGK-Neo-SV40 polyadenylation signal (pA)-FRT-loxP sequence in intron 2 of the gene and an additional loxP site in intron 3 to create the Sec24c-GT (tm1a(EUCOMM)Wtsi) allele. C57BL/6N-derived JM8.N4 embryonic stem (ES) cells were used to create the mutation. Chimeras were crossed with B6(Cg)-Tyrc-2J/J (see Stock No. 000058) to achieve germline transmission. The lacZ and neomycin segments were excised with germline Flp recombinase (see Stock No. 005703), leaving exon 3 flanked by loxP sites. Mice were backcrossed to C57BL/6J for two generations to remove the FLP transgene. The Tyrc-2J allele was bred out of the line.
|Allele Name||targeted mutation 1c, Wellcome Trust Sanger Institute|
|Allele Type||Targeted (Conditional ready (e.g. floxed))|
|Gene Symbol and Name||Sec24c, Sec24 related gene family, member C (S. cerevisiae)|
|Strain of Origin||C57BL/6N|
|General Note||Cell line EPD0241_2_A11 was successfully used to make chimeric mice. Germline transmission was accomplished. J:232065|
|Molecular Note||The L1L2_Pgk_P cassette was inserted at position 20679037 of Chromosome 14 upstream of exon 3. The cassette is composed of an FRT site followed by lacZ sequence and a loxP site. This first loxP site is followed by neomycin resistance gene under the control of the PGK promoter, SV40 polyA, a second FRT site and a second loxP site. A third loxP site is inserted downstream of exon 3 at position 20679926. A "conditional ready" (floxed) allele was created by flp recombinase expression in mice, deleting the lacZ seqences and neomycin selection cassette, leaving exon 3 flanked by loxP sites.|
Heterozygotes and homozygotes are viable and fertile.
When using the B6(Cg)-Sec24ctm1c(EUCOMM)Wtsi/J mouse strain in a publication, please cite the originating article(s) and include JAX stock #024867 in your Materials and Methods section.