Titin provides a molecular blueprint for muscle sarcomere assembly and sarcomere length can vary according to titin isoform expression. If variations in sarcomere length influence muscle fascicle length, this may provide an advantage for running performance. Thus the aim of this study was to investigate if the titin (TTN) rs10497520 polymorphism was associated with muscle fascicle length in recreationally active men (RA; n = 137) and marathon personal best time in male marathon runners (MR; n = 141). Fascicle length of the vastus lateralis was assessed in vivo using B-mode ultrasonography at 50% of muscle length in RA. All participants provided either a whole blood, saliva or buccal cell sample, from which DNA was isolated and genotyped using real-time polymerase chain reaction. Vastus lateralis fascicle length was 10.4% longer in CC homozygotes, those carrying two copies of the C-allele, than CT heterozygotes (p = 0.003) in RA. In the absence of any TT homozygotes, reflective of the low T-allele frequency within Caucasian populations, it is unclear if fascicle length for this group would have been smaller still. No differences in genotype frequency between the RA and MR groups were observed (p = 0.500), although within the MR group the T-allele carriers demonstrated marathon personal best times 2 min 25 s faster than CC homozygotes (p = 0.020). These results suggest that the T-allele at rs10497520 in the TTN gene is associated with shorter skeletal muscle fascicle length and conveys an advantage for marathon running performance in habitually trained men. This article is protected by copyright. All rights reserved.
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机译:替丁蛋白为肌肉肌节组装提供了分子蓝图,肌节长度可根据肌动蛋白同工型表达而变化。如果肌小节长度的变化影响肌肉束长度,则可以为跑步表现提供优势。因此,本研究的目的是研究在体育活动活跃的男性(RA; n = 137)中,titin(TTN)rs10497520多态性是否与肌肉束长度相关,以及男性马拉松运动员的马拉松最佳个人时间(MR; n = 141) 。使用B型超声检查在RA肌肉长度的50%时评估了股外侧肌的束长度。所有参与者都提供了全血,唾液或颊细胞样品,使用实时聚合酶链反应从中分离DNA并进行基因分型。 CC纯合子(携带两个C等位基因)比RA中的CT杂合子(p = 0.003)长10.4%。在没有任何TT纯合子的情况下,这反映了白种人群体中较低的T-等位基因频率,尚不清楚该群体的束长度是否会更小。尽管在MR组中,T等位基因携带者表现出马拉松个人最佳时间比CC纯合子快25分钟(2分钟),但在RA和MR组之间没有观察到基因型频率的差异(p = 0.500)。这些结果表明,TTN基因中rs10497520处的T等位基因与较短的骨骼肌束长度相关,并为习惯训练的男子提供了马拉松跑步表现的优势。本文受版权保护。版权所有。
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