Fine mapping of a major QTL influencing morphine preference in C57BL/6 and DBA/2 mice using congenic strains.
C57BL/6J (B6) and DBA/2J (D2) mice differ in behaviors related to substance abuse, including voluntary morphine consumption and preference in a two-bottle choice paradigm. Two major quantitative trait loci (QTL) for morphine consumption and preference exist between these strains on chromosomes (Chrs.) 6 and 10 when the two-bottle choice involves morphine in saccharin vs quinine in saccharin. Here, we report the refinement of the Chr. 10 QTL in subcongenic strains of D2.B6-Mop2 congenic mice described previously. With these subcongenic mouse strains, we have divided the introgressed region of Chr. 10 containing the QTL gene(s) into two segments, one between the acromere and Stxbp5 (in D2.B6-Mop2-P1 mice) and the other between marker D10Mit211 and marker D10Mit51 (in D2.B6-Mop2-D1 mice). We find that, similar to B6 mice, the D2.B6-Mop2-P1 congenic mice exhibit a strong preference for morphine over quinine, whereas D2.B6-Mop2-D1 congenic mice avoid morphine (similar to D2 mice). We have also created a line of double congenic mice, B6.D2-Mop2.Qui, which contains both Chr. 10 and Chr. 6 QTL. We find that they are intermediate in their morphine preference scores when compared with B6 and D2 animals. Overall, these data suggest that the gene(s) involved in morphine preference in the morphine-quinine two-bottle choice paradigm are contained within the proximal region of Chr. 10 (which harbors Oprm1) between the acromere and Stxbp5, as well as on distal Chr. 6 between marker D6Mit10 and the telomere.
Doyle
Glenn A
GA
Department of Psychiatry, Center for Neurobiology and Behavior, University of Pennsylvania, Philadelphia, PA 19104, USA. gadoyle@mail.med.upenn.edu
Furlong
Patrick J
PJ
Schwebel
Candice L
CL
Smith
George G
GG
Lohoff
Falk W
FW
Buono
Russell J
RJ
Berrettini
Wade H
WH
Ferraro
Thomas N
TN
D018712:Analgesics, Non-Narcotic / Q000494:pharmacology; D000701:Analgesics, Opioid / Q000494:pharmacology; D000818:Animals; D020296:Animals, Congenic / Q000235:genetics; D001923:Brain Chemistry / Q000187:drug effects* / Q000235:genetics*; D002874:Chromosome Mapping; D004193:Discrimination Learning / Q000187:drug effects / Q000502:physiology; D005518:Food Preferences / Q000502:physiology; D005819:Genetic Markers / Q000235:genetics; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D051379:Mice; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D009020:Morphine / Q000494:pharmacology*; D009021:Morphine Dependence / Q000235:genetics* / Q000378:metabolism / Q000503:physiopathology; D009419:Nerve Tissue Proteins / Q000235:genetics; D040641:Quantitative Trait Loci / Q000235:genetics*; D011803:Quinine / Q000494:pharmacology; D050683:R-SNARE Proteins / Q000235:genetics; D013045:Species Specificity
D018712:Analgesics, Non-Narcotic; D000701:Analgesics, Opioid; D005819:Genetic Markers; D009419:Nerve Tissue Proteins; D050683:R-SNARE Proteins; C112618:tomosyn protein, mouse; D009020:Morphine; D011803:Quinine