Phenotypes of Two JAX® Mice Strains Being Restored
JAX® NOTES Issue 505, Spring 2007
We are in the process of replacing two JAX® Mice strain colonies, whose phenotypes are gradually deteriorating due to genetic drift, with stocks derived from embryos cryopreserved early in the history of these strains (and therefore not affected by genetic drift). The first colony is that of strain B6CBA-Tg(HDexon1)62Gpb/1J (002810), a Huntington disease (HD) model originating from a transgenic line carrying the 5' end of the human HD gene. Compared to mice from the replaced colony, mice from the new colony have more CAG repeats (~154-159 vs. ~100-115), resulting in a more severe and earlier onset HD phenotype (9 to 11 weeks vs. later than 12 to 13 weeks). Mice from the new colony will retain the old strain name and stock number; mice from the replaced colony will be given a new strain name and stock number, B6CBA-Tg(HDexon1)62Gpb/3J (006494).
The second colony being replaced is that of strain MRL/MpJ-Faslpr/J (000485), a lupus-like model. Even though the two colonies are homozygous for the Faslpr mutation and have the same SNP profile in the region of the mutation, the new colony better represents the historically reported and expected lymphoproliferative lupus phenotype: compared to age- and sex-matched mice from the replaced colony, lymph nodes of 16-week old females and males from the new colony are, respectively, 4.5 and 10.1 times larger, splenomegaly is 3 to 6 times more severe, and life spans are greatly reduced. Mice from the new colony will retain the old strain name and stock number; mice from the replaced colony will be given a new strain name and stock number, MRL/MpJ-Faslpr/2J (006825).
We are in the process of expanding the two new colonies and will notify you when mice from these colonies are available for distribution. To help us plan the expansion and management of the two new colonies, please contact our Customer Service department at 1-800-422-MICE (6423) or 1-207-288-5845 and register your interest in one or both of the strains. We will continue to distribute mice from the replaced colonies as long as our customers need them.
Information on how the restoration of the two strains is progressing will be published on the JAX® Mice Web site and in future issues of JAX® NOTES and our JAX® Mice News newsletter.
We sincerely regret any negative impact that this restoration may have on your research. If you have any questions, please contact JAX® Customer Service at 1-800-422-MICE (6423) or 1-207-288-5845.
