Background: Red meat is as an important dietary source that
provides part of the nutritional requirements such as proteins,
minerals, B-complex vitamins and essential fatty acids. Intramuscular fat is located throughout skeletal muscles. It is responsible for the marbling seen in certain cuts of beef. Marbling is a trait of major economic relevance that positively
inAuences sensory quality aspects, including Aavor, juiciness
and tenderness of meat.
Objectives: the objective of this study was to identify cellular
signaling pathways regulating muscle marbling in beef cattle
using microarray gene expression data.
Methods: publicly available preprocessed transcriptomics
data (E-GEOD-46411) from a study by Sadkowski et al was
used. They measured gene expression in skeletal muscle of
well-marbled beef and lean-marbled beef using Agilent microarrays. Pathway analysis was performed with the pathway
visualization and analysis tool, PathVisio.
Results: The regulation of marbling is possibly the result of
interaction of signaling pathways in muscle, fat and intramuscular connective tissue, identifying these processes with
pathway analysis can help to decipher the key marbling processes. Pathway analysis revealed 17 pathways that showed
differences in expression (z-score > 1.96) between well-marbled and lean marbled beef. MAPK (WP998) and P38 MAPK
(WP1037) signaling, two pathways well known two affect
lipid metabolism, were enriched in the well marbling breed.
In addition, the signaling pathways “hypertrophy modelâ€-, “microRNAs in cardio myocyte hypertrophyâ€- and
“physiological and pathological hypertrophy of the heartâ€-
that play a role in tissue development were affected. Interestingly, the analyses also demonstrated that pathways related to
immune response (IL signaling, TCR signaling and Toll-like
receptor signaling pathways) and insulin signaling, mitochondrial gene expression and Vitamin D metabolism were
enriched and might act together with the pathways related