Circular RNA Profiling Reveals an Abundant circEch1 That Promotes Myogenesis and Differentiation of Bovine Skeletal Muscle

Beef
is considered to be a good quality meat product because it
contains linoleic acid and specific proteins, which can bring significant
benefits to health. Circular RNAs (circRNAs) have been reported to
regulate skeletal myogenesis. RNA-seq was used to investigate the
circRNA molecular regulatory mechanisms with respect to differences
in muscle quality between buffalo and cattle. A total of 10,449 circRNA
candidates were detected, and 1128 of these were found to be differentially
expressed between cattle and buffalo muscle tissue libraries. Differentially
expressed 23 circRNAs were verified by qPCR. CircEch1, one of the
most up-regulated circRNAs during muscle development, was subsequently
characterized. CCK-8 (65.05 ± 2.33%, P <
0.0001), EdU (72.99 ± 0.04%, P < 0.001),
and Western blotting assays showed that overexpression of circEch1
inhibited the proliferation of bovine myoblasts but promoted differentiation. In vivo studies suggested that circEch1 stimulates skeletal
muscle regeneration. These results demonstrate that the novel regulator
circEch1 induces myoblast differentiation and skeletal muscle regeneration.
They also provide new insights into the mechanisms of circRNA regulation
of beef quality.