Mapping Data

Experiment

• Experiment
  TEXT-QTL
• Chromosome
  2
• Reference
  J:110033 Lionikas A, et al., Genetic determinants of weight of fast- and slow-twitch skeletal muscles in old mice. Mamm Genome. 2006 Jun;17(6):615-28
• ID
  MGI:3640578

Genes

Gene	Assay Type
Skmw8	visible phenotype
D2Mit300	PCR amplified length variant
Skmw9	visible phenotype
D2Mit304	PCR amplified length variant

Notes

• Experiment
  Linkage analysis was performed to identify QTLs associated with fast- and slow-twitch muscle weights in aged animals. 321 (C57BL/6J x DBA/2J)F2 intercross animals surviving to age 808 days were phenotyped. Ninety-seven polymorphic markers were used to screen the F2 population. In addition 239 animals from 22 BXD recombinant inbred strains were phenotyped at age 805 days. Aged animals from parental strain DBA/2J exhibit decreased mean muscle weights compared to parental strain C57BL/6J. Loci reaching statistical significance of LOD>4.9 are assigned QTL nomenclature and reported below.
  
  Linkage to soleus muscle weight (LOD=6.9) and tibialis anterior (TA) muscle weight (LOD=5.4) mapped to 97 cM with peak marker D1Mit221 on mouse Chromosome 1. This locus is Skmw6(skeletal muscle weight 6). The 1.5 LOD support interval spans 92 cM to telomere. This locus explains 1.2% of the variance. DBA/2J-derived alleles at Skmw6 confer increased soleus muscle weight with dominant inheritance. However, heterozygosity at this locus confers increased TA muscle weight compared to homozygosity for either C57BL/6J or DBA/2J alleles.
  
  A nearby locus at 93 cM (D1Mit16) is linked to gastrocnemius muscle weight with LOD=4.9. This QTL is designated Skmw12 (skeletal muscle weight 12).The1.5 LOD support interval spans 89 cM - 102 cM. C57BL/6J-derived alleles at Skmw12 confer increased muscle weight with dominant inheritance.
  
  Linkage to extensor digitorum longus (EDL) muscle weight mapped to 43 cM with peak marker D2Mit300 on mouse Chromosome 2 (LOD=9.4). This locus, Skmw8 (skeletal muscle weight 8), also exhibits suggestive linkage to tibialis anterior (TA) muscle weight with LOD=4.3. The 1.5 LOD support interval spans 11 cM - 66 cM. Skmw8 explains 2.3% of the TA muscle weight variance and 0.7% of the TA muscle weight variance. C57BL/6J-derived alleles at Skmw8 confer increased EDL weight with additive inheritance and increased TA weight with recessive inheritance.
  
  Linkage to gastrocnemius muscle weight mapped to 63 cM with peak marker D2Mit304(LOD=8.3). This locus is Skmw9 (skeletal muscle weight 9). The 1.5 LOD support interval spans 51 cM - 76 cM. C57BL/6J-derived alleles at Skmw9 confer increased gastrocnemius muscle weight with additive inheritance.
  
  Linkage to gastrocnemiusmuscle weight mapped to 5.4 cM on mouse Chromosome 3 with peak marker D3Mit264 (LOD=7.9). This locus is Skmw1 (skeletal muscle weight 1). The 1.5 LOD support interval spans 0 cM - 13 cM. C57BL/6J-derived alleles at Skmw1 confer increased gastrocnemius muscle weight in aged animals with additive inheritance. This locus explains 0.8% of the trait variance.
  
  Linkage to extensor digitorum longus (EDL) weight mapped to 41 cM on mouse Chromosome 5 with peak marker D5Mit10 (LOD=5.1). This locus is designated Skmw13 (skeletal muscle weight 13) and explains 1% ofthe trait variance. The 1.5 LOD support interval spans 9 cM - 65 cM. C57BL/6-derived alleles at Skmw13 confer increased EDL weight with additive inheritance.
  
  Linkage to soleus muscle weight mapped to 71 cM on mouse Chromosome 6 with peak marker D6Mit15 (LOD=5.6).This locus explains 2% of the variance and is designated Skmw14 (skeletal muscle weight 14). The 1.5 LOD support interval spans 65 cM - 74 cM. Homozygosity for C57BL/6J-derived alleles confersdecreased soleus muscle weight in 800 day old animals.
  
  Linkage to gastrocnemius muscle weight mapped to 24.5 cM with peak marker D6Mit188 (LOD=5.6) and 58 cM with peak marker D6Mit111 (LOD=5.5). The proximal locus is Skmw10 (skeletal muscle weight 10) and the distal locus is designated Skmw15 (skeletal muscle weight 15). The 1.5 LOD support intervals span 0 cM - 40 cM for Skmw10 and 45 cM - 72 cM for Skmw15. Homozygosity for C57BL/6J-derived alleles at these loci appears to increase gastrocnemius muscleweight in males at 200days of age butexhibits a decreasing effect at 800days of age.
  
  Linkage to soleus muscle weight mapped to 32 cM on mouse Chromosome 8 with peak marker D8Mit249 (LOD=7.1). This locus is named Skmw16 (skeletal muscle weight 16). The 1.5 LOD support interval spans 27 cM - 47 cM. Heterozygosity at this locus confer increased soleus muscle weight compared to either C57BL/6J or DBA/2J homozygotes.
  
  Linkage to extensor digitorum longus (EDL) muscle weight mapped to 54 cM with peak marker D8Mit211 (LOD=6.4). This locus is Skmw2 (skeletalmuscle weight 2). The 1.5 LOD-support intervals spans 50 cM - 59 cM. DBA/2J-derived alleles at Skmw2 confer increased EDL muscle weight with dominant inheritance.
  
  Linkage to gastrocnemius muscle weight mapped to 25 cM with peak marker D8Mit191 (LOD=6.6) on Chromosome 8. This locus is Skmw19 (skeletal muscle weight 19). The 1.5 LOD - support interval spans 15 cM- 32 cM. DBA/2J derived alleles at Skmw19 confer increased soleus muscle weight with dominant inheritance. This locus accounts for 1.0% of the variance.
  
  Linkage to tibialis anterior (TA) weight mapped to 56 cM on mouse Chromosome 9 with peak marker D9Mit212 (LOD=8.2). This locus may be the same as Skmw11 (skeletal muscle weight 11). The 1.5 LOD support interval spans 48 cM - 67 cM. C57BL/6J-derived alleles confer increased TA muscle weight with additive inheritance. This locus explains 1.3% of the variance.
  
  Linkage to tibialis anterior (TA) weight mapped to 18 cM on mouse Chromosome 11 with peak marker D11Mit86 (LOD=7.1). This locus is designated Skmw17 (skeletal muscle weight 17) and also showssuggestive linkage to extensor digitorum longus (EDL) weight with LOD=4.5.The 1.5 LOD support interval spans 9 cM - 31 cM. This locus explains 0.9% of the EDL weight variance. DBA/2J-derived alleles at Skmw17 confer increased EDL weight with dominant inheritance.
  
  Linkage to soleus muscle weight mapped to 54 cM on mouse Chromosome 13 with peak marker D13Mit230 (LOD=5.1). This locus explains 1.8%of the variance and is designated Skmw18 (skeletal muscle weight 18). The 1.5 LOD support interval spans 46 cM - 71cM. C57BL/6J-derived alleles at Skmw18 confer increased soleus muscle weight with additive inheritance.
  
  Suggestive linkages to soleus muscle weight mapped to 17 cM on chromosome 5 near D5Mit227 (LOD=4.7), 37 cM on chromosome 14 near D14Mit194 (LOD=4.6), 44 cM on chromosome 16 near D16Mit191 (LOD=4.5),93 cM on chromosome 17 near D17Mit93 (LOD=4.3), and 31cM on chromosome X near DXMit95.
  
  Suggestive linkage to tibialis anterior weight mapped to 55 cM on chromosome 6 near D6Mit149 (LOD=4.5), 35 cM on chromosome 17 near D17Mit93 (LOD=4.8), 24 cM on chromosome 18 near D18Mit123 (LOD=4.6), and 17 cM onchromosome X near DXMit166.
  
  Suggestive linkage to extensor digitorum longus weight mapped to 16 cM on chromosome 7 near D7Mit69 (LOD=4.5), 7 cM on chromosome 9 near D9Mit64 (LOD=4.5), 20 cM on chromosome 11 near D11Mit86 (LOD=4.5), and 41 cM on chromosome 16 near D16Mit4 (LOD=4.3).
  
  Suggestive linkage to gastrocnemius weight mapped to 75 cM on chromosome 13 near D13Mit35 (LOD=4.5) and 40.2 cM on mouse Chromosome 17 near D17Mit93 (LOD=4.4).