Transcriptome-Wide Analysis of Differential Morphometric Growth in Modern Broiler Chickens and a Heritage Line

Modern broiler chickens have been selected for rapid growth and optimal feed efficiency. Comparing modern and heritage broiler lines provides insight into the changes that have occurred during human directed selection.  Previous work comparing Ross708 and a Heritage line maintained at the University of Illinois revealed significant differences in normalized organ sizes at different age points. In this study, we have analyzed morphometric data from both heat stressed and control birds of both lines and investigated gene expression patterns in tissue samples from the liver, heart, breast muscle, duodenum, and cerebellum. Transcriptome libraries were generated from these tissues using the Illumina TruSeq RNA sample prep kit with sequencing yielding over 5 million tags per sample.  Comparing gene expression levels between the tissues provides insight into the relative genetic complexity of each, with heart, duodenum, and brain samples displaying the largest amount of unique gene expression.  Additionally, the relationship between Ct values obtained from qPCR experiments were compared with RPKM values obtained from ERANGE to assess their relative accuracy and establish a correlation between the two measurements.