Insight into genetics underlying muscle growth can lead to pharmacological targets for treatment of muscle wasting conditions. The telomeric region of chromosome 10, between markers rs3676616 and D10Utsw1, contains genes that might be associated with signaling pathways involved in muscle growth, Stat2 (Wang et al, 2008) and metabolism, Cs (Ratkevicius et al, 2010). The non-synonymous polymorphisms in Stat2, and Cs genes are present between the commonly used laboratory mouse strains, C57BL/6J (B6) and A/J, and can provide a useful research model. The aim of the study was to investigate the role of this genomic region in the compensatory skeletal muscle growth.Synergist ablation method was used in the B6, and congenic B6.A-(rs3676616-D10Utsw1)/Kjn (B6.A) strain, and in the offspring (F1) of the cross between these two strains. Genotypic difference between the B6 and B6.A strains is restricted to a ~1.5 Mb region, between rs3676616 and D10Utsw1, where the A/J allele was introgressed in the congenic strain. Males (M; n=7-8 per strain) and females (F; n=5-9 per strain) at 12 weeks of age were used. A compensatory growth of soleus and plantaris muscles in the left hind limb was induced by ablation of gastrocnemius. Right hind limb remained intact and served as control. Eight weeks later animals were sacrificed, soleus and plantaris muscles were removed from both legs and weighed to a precision of 0.1 mg. Body weight (BW) before ablation and at the end of experiment was measured. Data (presented as mean ± SD) were analyzed using 2-way ANOVA (genotype and sex) with repeated measures (treatment) where appropriate.The genotype did not affect (p>0.05) BW (B6: (M) 26.7±2.0 g, (F) 20.5±0.7 g; F1: (M) 25.0±1.3 g, (F) 20.9±0.8 g; B6.A: (M) 26.0±1.3 g, (F) 21.4±1 g), soleus (B6: (M) 8.8±0.9 mg, (F) 6.8±0.6 mg; F1: (M) 8.3±0.7 mg, (F) 6.6±0.6 mg; B6.A: (M) 8.9±0.6 mg, (F) 6.9±0.7 mg) or plantaris (B6: (M) 17.9±1.3 mg, (F) 13.0±0.9 mg; F1: (M) 17.4±1.0 mg, (F) 13.7±1.2 mg; B6.A: (M) 18.3±1.7 mg, (F) 13.4±0.8 mg) muscle weight. During the course of the study, BW of mice significantly increased (p<0.001), but did not differ between strains. It indicates that surgical intervention did not affect animal health status adversely. The overloaded muscles were significantly heavier (p<0.001). Soleus muscle increased by 1.5 fold independently of genotype (p=0.64). The increase in plantaris weight was affected by genotype (Genotype x Treatment, p<0.0001). The B6 animals gained more weight (p<0.001), 2.2-fold, compared to the F1 or B6.A, 1.8-fold each. There was no significant sex effect or genotype by sex interaction in soleus or plantaris response to ablation (p>0.05).Our results suggest that the telomeric region of mouse chromosome 10 contains important regulator(s) of hypertrophy in the muscles dominated by the fast twitch fibres.