C57BL/6NJ

Stock number: 005304
Product name: B6N
Strain synonyms: Black 6N
Research areas: Cell Biology Research, Developmental Biology Research, Mouse/Human Gene Homologs, Research Tools, Sensorineural Research

Description

This is an NIH subline of C57BL/6. It was separated from C57BL/6J in 1951. Five SNP differences have been identified that distinguish C57BL/6J from C57BL/6ByJ and C57BL/6NJ. This strain does not have the deletion in the Nnt gene that has been found in the C57BL/6J strain (Stock No. 000664).

Detailed description

This is an NIH subline of C57BL/6. It was separated from C57BL/6J in 1951. 5 SNP differences have been identified that distinguish C57BL/6NJ from C57BL/6J and C57BL/6ByJ. Both C57BL/6ByJ and C57BL/6NJ type as follows: 08-015199792-M (rs3709624) is C; 11-004367508-M (rs3659787) is A; 13-041017317-M (rs3722313) is C; 15-057561875-M (rs3702158) is G; 19-049914266-M (rs3724876) is T. C57BL/6J types as follows: 08-015199792-M is T; 11-004367508-M is G; 13-041017317-M is T; 15-057561875-M is A; 19-049914266-M is G (Petkov and Wiles 2005.)

This strain does not have the deletion in the Nnt gene that has been found in the C57BL/6J strain (Stock No. 000664). C57BL/6NJ mice are homozygous for Cyfip2^M1N, a spontaneous mutation in the cytoplasmic FMR1 interacting protein 2 that results in an amino acid substitution of phenylalanine for serine at position 968 (S968F). The mutation is found in all C57BL/6N substrains but is not present in the C57BL/6J strain or substrains. The mutation results in 45% lower acute response to cocaine as measured by locomotor hyperactivity (Kumar et al., 2013). This strain is also homozygous for the Del(13)1N deletion, common to the NIH sublines, which includes Zfp998 and Zfp997 and has been found to cause the loss of transcriptional repression of non-ecotropic endogenous retroviruses in C57BL/6NJ compared with C57BL/6J, which does not have this deletion (Treger et al., 2019). A 2022 study found vaginal septa in 5.5% of C57BL/6NJ females.

Development

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 2005 some of these embryos frozen in 1997 were sent to The Jackson Laboratory where they were thawed and gave rise to C57BL/6NJ. Thus, C57BL/6NJ is devoid of mutations that may have arisen in any C57BL/6N sublines that remained on the shelf after the 1984 freeze. The embryos received by The Jackson Laboratory were thawed, the colony expanded, and re-frozen immediately. This strain is maintained with frequent replenishment from this frozen stock in order to arrest genetic drift.

Allele

Symbol: Crb1^rd8
Name: retinal degeneration 8
MGI accession ID: MGI:2676366
Generation method: Spontaneous
Marker symbol: Crb1
Marker name: crumbs family member 1, photoreceptor morphogenesis associated
Chromosome: 1
Strain of origin: C57BL/6By or C57BL/6N
Molecular note: The mutation in the rd8 mouse has been identified as a single base deletion of a C (G on forward strand) at coding nucleotide 3481 in the gene. This deletion causes a frame shift and a premature stop codon that truncates the transmembrane and cytoplasmic domain of the protein after amino acid 1207. This mutation has been found to be present in all sublines of C57BL/6N and in C57BL/6ByJ, but not in any C57BL/6J subline. It occurred sometime between transfer of mice from JAX to NIH, in 1951, and from NIH to Donald Bailey, in 1961.

Allele

Symbol: Cyfip2^M1N
Name: mutation 1, National Institutes of Health
MGI accession ID: MGI:5527294
Generation method: Spontaneous
Marker symbol: Cyfip2
Marker name: cytoplasmic FMR1 interacting protein 2
Chromosome: 11
Strain of origin: C57BL/6N
Molecular note: An G-to-A mutation at 46,222,615 bp of chromosome 11 (GRCm38) occurred between 1961 and 1974 in the C57BL/6N strain that resulted in the amino acid substitution of serine with phenylalanine at position 968 (p.S968F). This mutation is found in all C57BL/6N substrains (C57BL/6NCrl, C57BL/6NTac and C57BL/6NJ) but is not present in the C57BL/6J strain or substrains (C57BL/6Ei, C57BL/6EiJ, C57BL/6ByJ and C57BL/6By). The mutation destabilizes the protein leading to decreased half-life.

Allele

Symbol: Nlrp12^C57BL/6N
Name: C57BL/6N
MGI accession ID: MGI:5818576
Generation method: Spontaneous
Attributes: Not Applicable
Marker symbol: Nlrp12
Marker name: NLR family, pyrin domain containing 12
Chromosome: 7
Strain of origin: C57BL/6N
Molecular note: A sequence variant is identified in C57BL/6N (C) as compared to C57BL/6J (T) at position 3,222,537 (GRCm38). The polymorphism is located in the C-terminal leucine-rich repeat domain and results in a lysine to arginine change at amino acid residue 1034 (p.K1034R).

Allele

Symbol: Cox7a2l^s
Name: short
MGI accession ID: MGI:6276120
Generation method: Not Applicable
Attributes: Not Specified
Marker symbol: Cox7a2l
Marker name: cytochrome c oxidase subunit 7A2 like
Chromosome: 17
Strain of origin: multiple strains
Molecular note: This allele contains a 6 bp microdeletion causing the loss of two amino acids and truncating the protein to 111 amino acids instead of 113 amino acids. It is found in BALB/cAnCrl, BALB/cJ, C57BL/6Cr, C57BL/6JCrl, C57BL/6JOlaHsd, C57BL/6NCrl, C57BL/6NJcl, C57BL/6NHsd, C57BL/6NTac, C57BL/6NJ, B6(CG)-Tyr/J, C57BL/6JClr, C57BL/6JArc, C57BL/6JJcl, C57BL/6JJmsSlc, C57BL/6JOla, C57BL/6JOlaHsd, C57BL/6JRcc, C57BL/6JRccHsd, C57BL/6JBom, and C57BL/6JBomTac mice.
General note: Querying the sequences of the Sanger Mouse Genomes Project reveals that the short allele with its 6 bp deletion exists in C57BL/6J, C57BL/10J, C57BL/6NJ, C58/J, BALB/cJ, C3H/HeH, 129S5/SvEvBrd, NZW/LacZ, and SEA/GnJ, but the long allele lacking the deletion exists in 129S1/SvImJ, A/J, AKR/J, BTBR T⁺ Itpr3^tf/J, BUB/BnJ, C3H/HeJ, C57BR/cdJ, C57L/J, CAST/EiJ, CBA/J, DBA/1J, DBA/2J, FVB/NJ, I/LnJ, KK/HiJ, LEWES/EiJ, LP/J, MOLF/EiJ, NOD/ShiLtJ, NZB/BlNJ, NZO/HlLtJ, PWK/PhJ, RF/J, SPRET/EiJ, ST/bJ, WSB/EiJ, ZALENDE/EiJ.

Allele

Symbol: Del(13)1N
Name: Deletion, Chr 13, NIH 1
MGI accession ID: MGI:6514360
Generation method: Spontaneous
Attributes: Modified regulatory region
Marker symbol: Del(13)1N
Marker name: Deletion, Chr 13, NIH 1
Chromosome: 13
Strain of origin: C57BL/6N
Molecular note: This multigenic deletion, present in C57BL/6NJ and C57BL/6NTac but not C57BL/6J inbred strains, is approximately 1 Mb in size and spans from Chr13:65.66Mb-66.67Mb which includes several lincRNA and pseudogenes along with Zfp998 and Zfp997, with the distal breakpoint falling between Zfp997 and Zfp640.