Journal Article

IGFN1_v1 is required for myoblast fusion and differentiation

Li, Xiang, Blanco, Gonzalo, Cracknell, Tobias, Baker, Jane, Haynes, Andrew R.

2017

Overview

Igfn1 is a complex locus that codes for multiple splicing variants of Immunoglobulin- and Fibronectin-like domain containing proteins predominantly expressed in skeletal muscle. To reveal possible roles for Igfn1, we applied non-selective knock-down by shRNAs as well as specific targeting of Igfn1 exon 13 by CRISPR/Cas9 mutagenesis in C2C12 cells. Decreased expression of Igfn1 variants via shRNAs against the common 3'-UTR region caused a total blunting of myoblast fusion, but did not prevent expression of differentiation markers. Targeting of N-terminal domains by elimination of exon 13 via CRISPR/Cas9 mediated homologous recombination, also resulted in fusion defects as well as large multinucleated cells. Expression of IGFN1_v1 partially rescued fusion and myotube morphology in the Igfn1 exon 13 knock-out cell line, indicating a role for this variant in myoblast fusion and differentiation. However, in vivo overexpression of IGFN1_v1 or the Igfn1 Exon 13 CRISPR/Cas9 targeting vector did not result in significant size changes in transfected fibres.

• Publisher: Public Library of Science
• Subject: 3' Untranslated regions / Adaptor Proteins, Signal Transducing / Animals / Base Sequence / Biology / Cell Differentiation - physiology / Cell Fusion / Cell Line / Cloning / Clustered Regularly Interspaced Short Palindromic Repeats / CRISPR / Cytology / Cytoskeleton / Defects / Differentiation / Exons / Fibers / Fibronectin / Fibronectins / Gene expression / Genetic aspects / Health aspects / Homologous Recombination / Homology / Immunoglobulin genes / Immunoglobulins / Insects / Markers / Mice / Muscle, Skeletal - cytology / Muscular diseases / Musculoskeletal system / Mutagenesis / Mutation / Myoblasts / Myoblasts - cytology / Proteins / Proteins - genetics / Proteins - physiology / Skeletal muscle / Splicing