Analysis of the turkey skeletal muscle transcriptome through development within a genetic line (Experiment 1)

The purpose of Experiment 1 was two-fold: a) to evaluate a unique set of negative, distance, and mismatch control probes on the newly designed 6K TSKMLO microarray, and b) to identify patterns of gene expression in skeletal muscle during development. Negative and mismatch controls confirmed specific hybridization using this array, and genes identified as differentially expressed between developmental stages by microarray analysis were confirmed by qRT-PCR. Novel candidate genes and pathways were identified as playing potentially crucial roles in turkey skeletal muscle development with implications for improving turkey meat quality defects and growth-induced myopathies long-term. This experiment utilized turkeys from two genetic lines: RBC2, a randomly bred control line representative of a 1967 commercial turkey, and F, a subline genetically selected from the RBC2 line for increased 16-week body weight. Skeletal muscle was collected at three critical developmental stages: 18-day embryo (18de; peak of hyperplasia), 1-day post-hatch (1d; shift from myoblast-mediated growth to satellite cell modulated growth by hypertrophy), and 16-week-old birds (16wk; completion of muscle formation and approximate age of commercial slaughter). Experiment 1 was designed to directly compare the three stages of skeletal muscle development: 18de vs. 1d, or 1d vs. 16wk, for each of the genetic lines. Experiment 1 contained 10 arrays per comparison, therefore, it contained 40 arrays total. Birds were randomly assigned to an array, and hybridizations were performed in random order.