Functional Genomics in Chickens: Development of Integrated-Systems Microarrays for Transcriptional Profiling and Discovery of Regulatory Pathways

摘要

The genetic networks that govern the differentiation and growth of major tissuesof economic importance in the chicken are largely unknown. Under a functionalgenomics project, our consortium has generated 30 609 expressed sequencetags (ESTs) and developed several chicken DNA microarrays, which represent theChicken Metabolic/Somatic (10 K) and Neuroendocrine/Reproductive (8 K) Systems(http://udgenome.ags.udel.edu/cogburn/). One of the major challenges facing functionalgenomics is the development of mathematical models to reconstruct functionalgene networks and regulatory pathways from vast volumes of microarray data. In initialstudies with liver-specific microarrays (3.1 K), we have examined gene expressionprofiles in liver during the peri-hatch transition and during a strong metabolic perturbation—fastingand re-feeding—in divergently selected broiler chickens (fast vs. slow-growth lines).The expression of many genes controlling metabolic pathwaysis dramatically altered by these perturbations. Our analysis has revealed alarge number of clusters of functionally related genes (mainly metabolic enzymesand transcription factors) that control major metabolic pathways. Currently, we areconducting transcriptional profiling studies of multiple tissues during development oftwo sets of divergently selected broiler chickens (fast vs. slow growing and fat vs. leanlines). Transcriptional profiling across multiple tissues should permit construction ofa detailed genetic blueprint that illustrates the developmental events and hierarchyof genes that govern growth and development of chickens. This review will brieflydescribe the recent acquisition of chicken genomic resources (ESTs and microarrays)and our consortium's efforts to help launch the new era of functional genomics inthe chicken.