Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology
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Neuropsychopharmacology · Apr 2005
Confirmation of a major QTL influencing oral morphine intake in C57 and DBA mice using reciprocal congenic strains.
C57BL/6 (B6) and DBA/2 (D2) mice exhibit disparate behavior when tested for voluntary morphine intake in a two-bottle choice drinking paradigm with B6 mice consuming 10 times more drug than D2 mice. Previous genetic mapping studies identified a locus, Mop2, on the proximal part of chromosome 10 that explained over half of the genetic variance in this mouse model of opioid self-administration. We constructed a set of reciprocal congenic strains between B6 and D2 mice in which the proximal portion of chromosome 10 has been introgressed from one strain onto the background of the other. ⋯ D2-Mop2 mice was decreased significantly relative to B6 and D2. B6-Mop2 mice. Overall, these data confirm the existence of a gene(s) on chromosome 10 proximal to D10Mit124 that has a strong influence on the difference in morphine drinking behavior between B6 and D2 mice.