Verification of quantitative trait loci located on chromosome 4 that affect mouse behaviors by use of congenic and sub-congenic strains generated from DBA/2 and C57BL/6 mice

Abstract

The open field test is a basic test used to assess exploratory behavior, anxiety, and locomotor activity in rodents. Some quantitative trait loci (QTLs) regarding mouse behavior in open field were identified so far. A QTL associated with grooming duration was identified in chromosome (Chr) 4 using recombinant inbred strain made from DBA/2 (D2) and C57BL/6 (B6) mice. We previously generated D2 congenic line, D2.B6-Sen1, in which most region of Chr 4 was replaced to B6 haplotype. In this paper, to confirm the position of this QTL and to investigate candidate genes, two sub-congenic lines, D2.B6-Sen1.1 and D2.B6-Sen1.2, were generated. From results of open field test with a congenic and two sub-congenic strains, we found that D2.B6-Sen1.2 increased grooming duration compared with D2, but D2.B6-Sen1.1 demonstrated opposite result, suggesting two genes responsible for grooming duration located in Chr 4. We also found that only D2.B6-Sen1 mice decreased the time in thigmotaxis zone, suggesting another gene responsible for this behavior located in B6-derived chromosomal region.