title: Chromosomal assignment of quantitative trait loci influencing baseline circulating total cholesterol level in male laboratory mice: report of a consomic strain survey and comparison with published results.
abstract: BACKGROUND
  An important risk for atherosclerosis is a low level of HDL cholesterol. Baseline HDL cholesterol is under complex genetic and environmental control. Here we report on results of male mice from a consomic strain survey and the parental inbred strains for baseline circulating total cholesterol concentration, which is almost the same as HDL cholesterol in chow fed mice. The consomic strains have been derived from C57BL/6J (host strain) and A/J (donor strain) inbred lines. The work contributes to the value of the mouse as an animal model for studying the genetic background of differences in baseline circulating total and HDL cholesterol levels.
  
  
  RESULTS
  The consomic strain survey suggested that mouse chromosomes 1, 7, 9, 14, 16, 17, 19, X, and Y contained at least one quantitative trait locus that is involved in baseline circulating total cholesterol concentration. All consomic lines, for which there is evidence that the substituted chromosome contains a quantitative trait locus, increase compared to the host strain baseline circulating total cholesterol concentration. Since there is evidence that 'body weight', 'age at blood sampling', 'time of the day blood was collected', and 'season' influence this phenotype, additional statistical analyses (with these variables as covariates) were performed. Now there is only evidence for quantitative trait loci on chromosomes 1, 8, 12, and Y. Taken the present results together with previous consomic strain surveys there is evidence that all mouse chromosomes carry quantitative trait loci that control baseline circulating total cholesterol levels. There was however little agreement between the present consomic strain results and previous sets of data. This might be explained by seasonal effects and differences in methodological variables such as age of the mice, fasting versus non-fasting, percentage of dietary fat, unanesthetized versus anesthetized mice, and the daily light-dark cycle.
  
  
  CONCLUSIONS
  The present findings, when compared with previous consomic strain surveys, clearly illustrate the complexity of the genetic-environmental architecture for the regulation of baseline circulating total cholesterol levels in mice. Different data can be obtained from different labs and it underscores that animal geneticists should present as accurate a picture as possible of the laboratory mouse's environment.
authors.affiliation: Division of Animal Welfare & Laboratory Animal Science, Department of Animals in Science and Society, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 2, P.O. Box 80166, 3508 TD, Utrecht, The Netherlands. H.A.vanLith@uu.nl.|Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, The Netherlands. H.A.vanLith@uu.nl.
authors.forename: Hein A
authors.initials: HA
authors.lastname: van Lith
authors.affiliation: Division of Animal Welfare & Laboratory Animal Science, Department of Animals in Science and Society, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 2, P.O. Box 80166, 3508 TD, Utrecht, The Netherlands. Marijke.Laarakker@bsci.com.|Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, The Netherlands. Marijke.Laarakker@bsci.com.|Current address: Boston Scientific Nederland B.V., Nieuwegein, The Netherlands. Marijke.Laarakker@bsci.com.
authors.forename: Marijke C
authors.initials: MC
authors.lastname: Laarakker
authors.affiliation: Division of Animal Welfare & Laboratory Animal Science, Department of Animals in Science and Society, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 2, P.O. Box 80166, 3508 TD, Utrecht, The Netherlands. J.G.vantKlooster@uu.nl.
authors.forename: José G
authors.initials: JG
authors.lastname: Lozeman-van't Klooster
authors.affiliation: Division of Animal Welfare & Laboratory Animal Science, Department of Animals in Science and Society, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 2, P.O. Box 80166, 3508 TD, Utrecht, The Netherlands. F.Ohl@uu.nl.|Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, The Netherlands. F.Ohl@uu.nl.
authors.forename: Frauke
authors.initials: F
authors.lastname: Ohl
mesh_terms: D000367:Age Factors; D000818:Animals; D001835:Body Weight; D008076:Cholesterol, HDL / Q000097:blood / Q000235:genetics*; D002874:Chromosome Mapping; D002875:Chromosomes / Q000737:chemistry*; D003433:Crosses, Genetic; D059647:Gene-Environment Interaction; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D010641:Phenotype; D017440:Photoperiod; D040641:Quantitative Trait Loci; D012621:Seasons; D013997:Time Factors
chemical_list: D008076:Cholesterol, HDL