Identification and Confirmation of Quantitative Trait Loci Regulating Alcohol Consumption in Congenic Strains of Mice (original) (raw)

Genotypic selection provides experimental confirmation for an alcohol consumption quantitative trait locus in mouse

Molecular Psychiatry, 1997

Genotypic selection sites on these chromosomes were selected because of the strength of evidence from our RI study and because provides experimental of encouraging early results from a concurrent intercross study of an F 2 derived from C57BL/6 and confirmation for an alcohol DBA/2 progenitor strains. A full genome assessment of complete data from the latter group will be presented consumption quantitative elsewhere. Here we present the relevant chromosome 12 and 15 analyses.

Hybrid Mice as Genetic Models of High Alcohol Consumption

Behavior Genetics, 2009

We showed that F1 hybrid genotypes may provide a broader variety of ethanol drinking phenotypes than the inbred progenitor strains used to create the hybrids (Blednov et al. in Alcohol Clin Exp Res 29:1949-1958-2005). To extend this work, we characterized alcohol consumption as well as intake of other tastants (saccharin, quinine and sodium chloride) in five inbred strains of mice (FVB, SJL, B6, BUB, NZB) and in their reciprocal F1 hybrids with B6 (FVBxB6; B6xFVB; NZBxB6; B6xNZB; BUBxB6; B6xBUB; SJLxB6; B6xSJL). We also compared ethanol intake in these mice for several concentrations before and after two periods of abstinence. F1 hybrid mice derived from the crosses of B6 and FVB and also B6 and SJL drank higher levels of ethanol than their progenitor strains, demonstrating overdominance for two-bottle choice drinking test. The B6 and NZB hybrid showed additivity in two-bottle choice drinking, whereas the hybrid of B6 and BUB demonstrated full or complete dominance. Genealogical origin, as well as non-alcohol taste preferences (sodium chloride), predicted ethanol consumption. Mice derived from the crosses of B6 and FVB showed high sustained alcohol preference and the B6 and NZB hybrids showed reduced alcohol preference after periods of abstinence. These new genetic models offer some advantages over inbred strains because they provide high, sustained, alcohol intake, and should allow mapping of loci important for the genetic architecture of these traits.

Genetic Contribution to Initial and Progressive Alcohol Intake Among Recombinant Inbred Strains of Mice

Frontiers in genetics, 2018

We profiled individual differences in alcohol consumption upon initial exposure and during 5 weeks of voluntary alcohol intake in female mice from 39 BXD recombinant inbred strains and parents using the drinking in the dark (DID) method. In this paradigm, a single bottle of 20% (v/v) alcohol was presented as the sole liquid source for 2 or 4 h starting 3 h into the dark cycle. For 3 consecutive days mice had access to alcohol for 2 h followed by a 4th day of 4 h access and 3 intervening days where alcohol was not offered. We followed this regime for 5 weeks. For most strains, 2 or 4 h alcohol intake increased over the 5-week period, with some strains demonstrating greatly increased intake. There was considerable and heritable genetic variation in alcohol consumption upon initial early and sustained weekly exposure. Two different mapping algorithms were used to identify QTLs associated with alcohol intake and only QTLs detected by both methods were considered further. Multiple sugges...

Alcohol Acceptance, Preference, and Sensitivity in Mice.. I. Quantitative Genetic Analysis Using BXD Recombinant Inbred Strains

Alcoholism: Clinical and Experimental Research, 1994

Although the recombinant inbred strain method was designed for molecular genetic analysis of linkage, it also provides powerful quantitative genetic analyses of heritability and genetic correlations. Measures of alcohol acceptance, alcohol preference, and hypnotic dose sensitivity (HDS) were assessed in 21 strains of mice from the BXD RI series. Sex differences were found to be significant at a phenotypic level. However, heritability estimates for acceptance, preference, and HDS are similar in males and females. Heritability estimates for the three measures are -0.20 for acceptance and preference, and 0.10 for HDS. Analyses of genetic correlations reveal that acceptance and preference share some degree of genetic influence, although they mostly operate under different genetically mediated mechanisms. HDS did not show a significant genetic relationship to either acceptance or preference. Strong correlations were obtained when acceptance, preference, and HDS strain means were correlated across male and female recombinant inbreds, suggesting substantial genetic similarity across sexes.

Genes on mouse Chromosomes 2 and 9 determine variation in ethanol consumption

Mammalian Genome, 1998

Quantitative trait locus (QTL) mapping efforts in alcohol (ethanol) research are beginning to generate promising data that may ultimately lead to the identification of genes influencing alcohol addiction. Rodents have been extensively utilized to study ethanol's rewarding and aversive effects, and to demonstrate the existence of genetic influences on traits such as free-choice ethanol-consumption, ethanol-conditioned place preference and ethanol-conditioned taste aversion. The purpose of the current investigation was to verify or eliminate from further consideration putative QTLs for free-choice ethanol consumption originally identified in BXD Recombinant Inbred (RI) strains and other informative genetic crosses. B6D2F 2 mice were utilized in a verification testing strategy to evaluate the viability of putative ethanol consumption QTLs. When data were combined from BXD RI, B6D2F 2 and short-term selected line (STSL) mapping studies, verification was obtained for two QTLs, one on Chromosome (Chr) 9 (proximal-mid) and another on Chr 2 (distal), and suggestive verification was obtained for QTLs on Chrs 2 (proximal), 3, 4, 7, and 15. In addition, the possible genetic association of ethanol consumption with conditioned place preference was evaluated. Genetic correlations were estimated from BXD RI strain means, and QTL maps for these traits were compared to evaluate the possibility of a genetic association. The correlational analysis yielded a trend (r ‫ס‬ 0.34, p ‫ס‬ 0.09), but no statistically significant results. However, comparisons of QTL mapping results between phenotypes suggested some possible genetic overlap for these traits, both putative measures of ethanol reward. These data suggest that the determinants of these two measures are genetically diverse, but may share some common genetic elements.

Derivation and Characterization of Replicate High- and Low-Alcohol Preferring Lines of Mice and a High-Drinking Crossed HAP Line

Behavior Genetics, 2010

Selectively breeding lines of mice and rats to differ in alcohol intake has proven useful for defining which traits correlate with high alcohol drinking behavior, as well as for creating animal models of alcoholism. This study reports the derivation of two novel sets of selected lines, High Alcohol Preferring (HAP) and Low Alcohol Preferring (LAP) replicate 2 and 3 lines. Mice were mass-selected using the same procedure as in the replicate 1 lines: using HS/Ibg as a progenitor, mice were selected for differences in 2-bottle choice intake of 10% alcohol during a 4-week testing period. In addition, another high drinking line, the crossed HAP (cHAP) line was selectively bred from a progenitors that were a cross of replicate 1 (S27) X replicate 2 (S21) HAP lines. All lines were characterized for saccharin intake. Overall, the response to selection of the HAP and LAP replicate 2 and 3 lines was quite similar. As anticipated, following selection, the cHAP line drank more than either parent HAP line (consuming 26.0 g/kg per day of alcohol by S11), suggesting that this method of crossing replicate lines and selecting from that cross captures more alleles than any single selected line, as well as producing a line with exceptionally high voluntary alcohol intake. As expected, saccharin consumption was highly associated with alcohol consumption; data from all 8 lines (HAP 1, 2, and 3, LAP 1, 2, and 3, HS/Ibg, and cHAP) indicated a genetic correlation between 10% alcohol and 0.32% saccharin intake of 0.917. Overall, these findings show the practicality of developing replicate lines divergent in alcohol preference, and validate a novel procedure for generating very high-drinking mouse populations.

Mapping of quantitative trait loci for ethanol preference in quasi-congenic strains

Alcohol, 2000

Ethanol preference, a component of alcoholism, has been known for four decades to differ greatly between C57BL/6 and BALB/c inbred mouse strains. For mapping quantitative trait loci (QTLs) that affect ethanol preference , we used a set of B6.C Recombinant QTL Introgression (RQI) strains, which carry about 5% of the donor BALB/cJ (C) genome on a C57BL/6ByJ (B6) background. After characterizing males of the progenitor and RQI strains for variations in ethanol preference, we scanned their genome for polymorphisms at 244 dinucleotide-repeat marker loci known to differ between B6 and C. Because of the introgression of BALB/c-type QTLs onto the B6 background, some strains showed ethanol preference significantly lower or higher than that of the background strain, suggesting that genetic interaction between ethanol preference QTLs and the background can be operative. The genomic region showing the strongest influence on ethanol preference was on mouse chromosome 15, and corresponds to human chr.12 q11-q13.

Epistatic quantitative trait loci for alcohol preference in mice

Behavior genetics, 2000

Alcohol consumption is a complex trait, responding to the influence of various genes and environmental influences acting in a quantitative fashion. Various studies in alcohol consumption processes have identified quantitative trait locus (QTL) regions across the mouse genome that appear to contribute to this phenotype. The purpose of this study was to examine the influence of interactions between alleles at different loci, a phenomenon known as epistasis, on previously identified QTLs for alcohol consumption in mice. A multiple regression model was developed and applied to test for the significance of the interaction between two QTLs and to quantify this interaction. Our results indicate the presence of epistasis between loci on mouse chromosomes 2 and 3 accounting for 7-8% of the variation in alcohol preference, respectively.

Genetic Mapping of Progressive Ethanol Consumption in the Diversity Outbred Mouse

Traditional genetic mapping studies using inbred crosses are a powerful tool for identifying chromosomal regions associated with ethanol-related traits, but typically have very large confidence intervals which make identification of specific and potentially causal candidate genes difficult. Diversity Outbred (DO) mice offer the ability to map quantitative trait loci (QTLs) associated with ethanol-drinking behaviors at a high resolution that allows for easier identification of candidate genes. Here, we exposed a population of 636 male DO mice to four weeks of intermittent ethanol access via a three-bottle choice paradigm, identifying 3 significant (Chrs 3, 4, and 12) and 12 suggestive loci for ethanol-drinking behaviors. The confidence intervals for these loci were narrow (1-4 Mbp for significant QTLs). We then further analyzed positional candidate genes using transcriptomics data from prefrontal cortex samples taken from 220 of these animals, as well as human GWAS data and prior gen...