Absence of the Z-disc protein α-actinin-3 impairs the mechanical stability of Actn3KO mouse fast-twitch muscle fibres without altering their contractile properties or twitch kinetics.

ABSTRACT:

Background

A common polymorphism (R577X) in the ACTN3 gene results in the complete absence of the Z-disc protein α-actinin-3 from fast-twitch muscle fibres in ~ 16% of the world's population. This single gene polymorphism has been subject to strong positive selection pressure during recent human evolution. Previously, using an Actn3KO mouse model, we have shown in fast-twitch muscles, eccentric contractions at L₀ + 20% stretch did not cause eccentric damage. In contrast, L₀ + 30% stretch produced a significant ~ 40% deficit in maximum force; here, we use isolated single fast-twitch skeletal muscle fibres from the Actn3KO mouse to investigate the mechanism underlying this.

Methods

Single fast-twitch fibres are separated from the intact muscle by a collag

SUBMITTER: Haug M 

PROVIDER: S-EPMC9219180 | biostudies-literature | 2022 Jun

REPOSITORIES: biostudies-literature