Fine mapping of "mini-muscle," a recessive mutation causing reduced hindlimb muscle mass in mice.
Prolonged selective breeding of Hsd:ICR mice for high levels of voluntary wheel running has favored an unusual phenotype (mini-muscle [MM]), apparently caused by a single Mendelian recessive allele, in which hindlimb muscle mass is reduced by almost 50%. We recently described the creation and phenotypic characterization of a population suitable for mapping the genomic location of the MM gene. Specifically, we crossed females from a high-runner line fixed for the MM allele with male C57BL/6J. F1 males were then backcrossed to the MM parent females. Backcross (BC) mice exhibited a 50:50 ratio of normal to MM phenotypes. Here, we report on linkage mapping of MM in this BC population to a 2.6335-Mb interval on MMU11. This region harbors approximately 100 expressed or predicted genes, many of which have known roles in muscle development and/or function. Identification of the genetic variation that underlies MM could potentially be very important in understanding both normal muscle function and disregulation of muscle physiology leading to disease.
Hartmann
John
J
Department of Nutrition, University of North Carolina, Chapel Hill, NC 27599, USA.
Garland
Theodore
T
Hannon
Robert M
RM
Kelly
Scott A
SA
Muñoz
Gloria
G
Pomp
Daniel
D
D000483:Alleles; D000818:Animals; D002874:Chromosome Mapping; D003433:Crosses, Genetic; D005260:Female; D005808:Genes, Recessive; D006614:Hindlimb / Q000033:anatomy & histology / Q000502:physiology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008813:Mice, Inbred ICR; D018482:Muscle, Skeletal / Q000033:anatomy & histology* / Q000502:physiology; D009154:Mutation; D009929:Organ Size; D010641:Phenotype