Differences in Aggressive Behavior and DNA Copy Number Variants Between BALB/cJ and BALB/cByJ Substrains
Some BALB/c substrains exhibit different levels of aggression. We compared aggression levels between male BALB/cJ and BALB/cByJ substrains using the resident intruder paradigm. These substrains were also assessed in other tests of emotionality and information processing including the open field, forced swim, fear conditioning, and prepulse inhibition tests. We also evaluated single nucleotide polymorphisms (SNPs) previously reported between these BALB/c substrains. Finally, we compared BALB/cJ and BALB/cByJ mice for genomic deletions or duplications, collectively termed copy number variants (CNVs), to identify candidate genes that might underlie the observed behavioral differences. BALB/cJ mice showed substantially higher aggression levels than BALB/cByJ mice; however, only minor differences in other behaviors were observed. None of the previously reported SNPs were verified. Eleven CNV regions were identified between the two BALB/c substrains. Our findings identify a robust difference in aggressive behavior between BALB/cJ and BALB/cByJ substrains, which could be the result of the identified CNVs.
KeywordsAggression Resident intruder BALB/c CNV Substrain
This work was supported by National Institutes of Health grants K01MH071555 and R01MH079424, and Brain Research Foundation and NARSAD Awards to S.C.D.
Disclosure/Conflict of interest
None of the authors reported biomedical financial interests or potential conflicts of interest.
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