Strain Code 01C55 [C57BL/6NCr] (C Black 6, C57 Black subline 6, B6)
Origin and Characteristics
In 1951 C57BL/6J, then at generation F32, were sent from The Jackson Laboratory
to The National Institute of Health where they were maintained via sibling mating
for decades. In 1980 this subline reached F126 and in 1984 embryos were cryopreserved
at the NIH cryopreservation facility. In approximately 1994 some of these embryos
were thawed and maintained via sibling mating and this subline was referred to as
B6(e84) to specify that it derived from the embryos frozen in 1984. In September
and October of 1997 a new set of embryos were cryopreserved from this thawed line
by backcrossing +F6 females to their +F5 fathers. In 1999 NCI received the latest
start of C57BL/6N.
Genetics
a, B, C
Intense black
Genes:
Car-2a, Ce-2a, Cs-1g, Es-1a, Es-3a,
Es-10a, Gpd-1a, Gpi-1b, Gusb, Hbaa,
Hbbs, Idh-1a, Lvb, Mod-1b, Mup-1b,
Pep-3a, Pgm-1a, Trfb
Hc1, H-2Db, H-2Kb, Lyb-2b, Lyt-1b,
Lyt-2b, Lyt-3b, Thy-1b, Tlab.
Diseases
Neoplastic (Spontaneous)
- Very low incidence of mammary tumors. (274)
Neoplastic (Induced)
- More than 75% developed pulmonary metastases within 50 days of amputation of legs
with autochthonous 3-methylcholanthrene-induced sarcomas providing a useful model
for studies of metastases and evaluation of cancer therapy in a minimal residual
disease setting. (790)
- N-butylnitrosourea induced leukemia in 91% of C57BL/6J mice; thymic lymphoblastic,
0-alloantigen-positive (T cell) leukemia predominated with a few cases of non-thymic
or stem cell leukemia. Thymectomy reduced the incidence to 64%. (659)
- 3-Methylcholanthrene induced brain tumors in 60% of males. (404)
- Dietary acetylaminofluorene or chlordane induced elevated 0-fetoprotein levels and
malignant hepatic lesions. (049)
- In comparison with other inbred strains, C57BL/6 is resistant to Gross, Tennant,
and Friend B viruses. (370)
Non-Neoplastic (Spontaneous)
- No dystrophic cardiac calcinosis detected in either sex. (160)
- Intestinal volvulus in a small percentage. (140)
Non-Neoplastic (Induced)
- Incidence of cortisone-induced cleft palate much higher on one commercial diet than
on another. (464)
- Relatively resistant to ectromelia. (632)
- Susceptible to infection with Leishmania tropica, but no clinical signs
of disease. (063)
- Benzo(a)pyrene administration at day 7 or 10 of gestation caused in utero toxicity
and teratogenicity more in C57BL/6 thant in Akr mice. Allelic differences at the
Ah locus in the fetus were correlated with dysmorphogenesis. (664)
Other Characteristics
Immunologic
- BCG pretreatment accelerated the recovery of granuloctye counts after cyclophosphamide-induced
leukopenia. (386)
- Delayed hypersensitivity to methylated serum albumin was enhanced by cycloposphamide
in young, but not old mice. (469)
- High interferon production after induction with Newcastle disease virus or mammary
tumor virus. (131)
- Responsive to pertussis HSF. (778,500)
- Two Lyt differentiated thymocyte populations were detected: one with
Lyt-1+ and one with Lyt 123+. (445)
Biochemical
- Aryl hydrocarbon hydroxylase is inducible by 3-methylcholanthrene and other polycyclic
hydrocarbons. The “responsive” Ahb allele is present.
(404,403)
- Morphine increased 3-methoxytyramine and cyclic AMP levels in striatum. (561)
- Liver alcohol dehydrogenase and aldehyde dehydrogenase activities 30% and 300% greater,
respectively, than those of DBA/2. (299)
Behavioral
- High preference for alcohol and for morphine presented in a saccharin vehicle. (794)
Misc.
- Survival time ws significantly shortened by the intraperitoneal, but not oral administration
of benzo(a)pyrene. (737)
- 3-Methylcholanthrene was more toxic to C57BL/6N primordial oocytes than to DBA/2N
oocytes. (447)
- Resistant to audiogenic seizures at all ages, but susceptibility enhanced by treatment
with excess thyroxine. (647,646)
- Less sensitive to analgesic action of morphine than DBA/2 and locomotor response
is higher. (561)
- Resistant to toxic effects of chloroform. (127,097)