Strain Code 01S35 [SJL/JCr]
Origin and Characteristics
SJL mice were developed by James Lambert at The Jackson Laboratory in 1955 from
three different sources of Swiss Webster mice. Received by NCI from Jackson Laboratory
in 1982. SJL mice display a very high incidence of reticulum cell sarcomas resembling
Hodgkin's disease around one year of age. Sarcomas first appear in the Peyer's patches
and mesenteric lymph nodes and later in the spleen, liver, thymus and other lymph
nodes. Most of the tumors are mixed-cell types classified as type B reticulum cell
neoplasms, but a few are type A histiocytomas. This strain is also characterized
by extreme aggression in males and its susceptibility to experimental autoimmune
encephalomyelitis (EAE) for multiple sclerosis research. SJL/J mice develop a spontaneous
myopathy resulting from a splice-site mutation in the Dysferlin gene. This
Dysf im allele has been shown to result in decreased levels of dysferlin
protein in SJL/J mice and makes this strain a good model for limb girdle muscular
dystrophy 2B. This spontaneous myopathy is characterized by a progressive loss of
muscle mass and strength corresponding with an increase in muscle pathology including
muscle fibers with central nuclei, variation in size, splitting, inflammatory infiltrate,
necrosis, and eventual replacement of muscle fiber with fat. While muscle weakness
can be detected as early as three weeks of age the greatest pathology occurs after
6 months of age. SJL/J mice have also been shown to have an increased rate of muscle
regeneration after injury when compared to BALB/c mice.