eNews April 04, 2013

A tool for telling apart C57BL/6J versus C57BL/6N substrains

If you need to know whether your mouse has a C57BL/6J (B6J, 000664), C57BL/6N (B6N, 005304), or mixed B6J;B6N background, The Jackson Laboratory’s (JAX’s) new C57BL/6 Substrain Characterization Panel may be just the tool you need.

Does it really matter?

Does it make a difference if your mouse has a B6J, B6N, or mixed B6J;B6N background? If your answer is “No,” consider the following:

  • C57BL/6J has the Nnt mutation, which modulates metabolism (Freeman et al. 2006; Shimomura et al. 2009) and immune response (Ripoll et al. 2012).
  • C57BL/6J and C57BL/6N vary in their fear responses (Radulovic et al. 1998; Stiedl et al. 1999) and how anesthetics affect their cardiac functions (Roth et al. 2002).
  • C57BL/6N mice and embryonic stem cells derived from them harbor the Rd8 mutation of the Crb1 gene, which causes developmental defects in photoreceptor segments (Mehalow et al. 2003; Mattapallil et al. 2012).
  • Mice produced by the Knockout Mouse Project (KOMP) are on a B6N background, which means that if you breed them to your B6 colony, you may be producing offspring with a mixed B6J;B6N genetic background.
  • When you receive strains from other sources, keeping the mutation on similar strain background reduces the chance that you will alter or lose your strain’s phenotype due to background modifier genes.

Once you know the background of your mouse strain, you can better identify the right control strain, which background to select for backcrossing, and what strain-specific phenotypes you should be aware of.

How you can use the C57BL/6 Substrain Characterization Panel

JAX’s new C57BL/6 Substrain Characterization Panel covers all autosomes and the X chromosome. The genome-wide spacing averages 15.4 +/- 7.3 Mb – equivalent to approximately 8 centiMorgans.

Number of SNP markers per chromosome in the C57BL/6 Substrain Characterization Panel:

Chr #

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

No of SNPs

12

10

9

8

7

8

9

8

7

7

7

7

7

7

6

6

5

6

4

10

You can send samples from your breeding projects to us for testing or we can perform testing in conjunction with any project you choose to outsource to us. JAX can perform genome scanning as a stand-alone service or integrate it with cryopreservation, rederivation or breeding services for you.

JAX distributes both C57BL/6J (000664) and C57BL/6NJ (005304) mouse strains

For more information about the C57BL/6 Substrain Characterization Panel, contact Technical Information Services at 1-800-422-6423, 1-207-288-5845, or micetech@jax.org.