Circular RNAs Mediate the Effects of Dietary Tryptophan on the Transformation of Muscle Fiber Types in Weaned Piglets

The nutritional composition of the diet significantly
impacts the
overall growth and development of weaned piglets. The current study
aimed to explore the effects and underlying mechanisms of dietary
tryptophan consumption on muscle fiber type transformation during
the weaning period. Thirty weaned piglets with an average body weight
of 6.12 ± 0.16 kg were randomly divided into control (CON, 0.14%
Trp diet) and high Trp (HT, 0.35% Trp) groups and maintained on the
respective diet for 28 days. The HT group of weaned piglets exhibited
highly significant improvements in growth performance and an increased
proportion of fast muscle fibers. Transcriptome sequencing revealed
the potential contribution of differentially expressed circular RNAs
toward the transformation of myofiber types in piglets and toward
the regulation of expression of related genes by targeting the microRNAs,
miR-34c and miR-182, to further regulate myofiber transformation.
In addition, 145 DE circRNAs were identified as potentially protein-encoding,
with the encoded proteins associated with a myofiber type transformation.
In conclusion, the current study greatly advances and refines our
current understanding of the regulatory networks associated with piglet
muscle development and myofiber type transformation and also contributes
to the optimization of piglet diet formulation.