Gene expression profiles for different tissues obtained from newly hatched (day 0) and 7 day-old broiler chickens

The embryo to neonate transition is a critical period of development that has significant impact on broiler production. During this time important genetic programs governing metabolism and growth are established. The goal of this work was to study the effects of early post-hatch (PH) development and time of initiation of feeding on activation of the genetic programs regulating tissue growth and metabolism in liver, brain, duodenum and breast muscle in broiler chickens. We used chicken genome GeneChip microarrays in a replicated experiment to detail the global program of gene expression in liver, whole brain, duodenum and breast muscle during the post-hatch transition in response to the initiation of feeding. Overall design: Tissue samples were collected at hatch and 7 days post-hatch for RNA extraction and hybridization on Affymetrix chicken genome GeneChip microarrays. We analyzed three replicate samples of total RNA on separate microarrays for each tissue at hatch and at day 7 post-hatch in order to increase the resolution of expression profiles. To that end, for each tissue we pooled samples from 4-5 individual chicks at both time points to increase representation of the replicate total RNA samples analyzed on the microarrays.