P0121Transcriptional Profiling of Post-Hatch Breast Muscle Development in Legacy and Modern Broiler Chickens (Gallus gallus)
Background: Agriculture provides excellent model systems for understanding how selective pressure, as applied by humans, can affect the genome of plants and animals. One such system is the intensive genetic selection applied by the poultry industry for meat production in the domesticated chicken. As a result, modern broilers exhibit enhanced growth, especially of the skeletal muscle, relative to their legacy counterparts. In this study we used RNA-seq to compare the transcriptomes of two representative modern and legacy broilers to identify differentially enriched genes in the breast muscle at days 6 and 21 post-hatch.
Results: Among the 15,945 genes analyzed, 10,841 were expressed at reproducible levels. At day 6 post-hatch 306 genes were differentially enriched between the two lines, including several positive and negative regulators of myogenic growth and development. The transcriptional profiles are more similar at the day 21 time-point with 193 genes differentially enriched between the modern and legacy lines. However, there is still differential expression of genes associated with myogenic growth.
Conclusions: This study identified several differentially enriched genes that regulate myogenic growth and differentiation, between the modern and legacy broiler lines. Specifically, differences in the ratios of several positive (IGF1, IGF1R, WFIKKN2) and negative (MSTN, ACE) myogenic growth regulators may, in part, explain the differences underlying the enhanced growth characteristics of the modern broilers. Future experiments will seek to analyze differential expression of non-coding RNAs and epigenetic modifications that may contribute to the remarkable growth characteristics of the modern broiler.