Selection Markers in Endocrine Genes
SELECTION FOR MARKERS IN ENDOCRINE GENES CAN REDUCE VISCERAL FATNESS IN POULTRY
Excess visceral fat in commercial chicken can affect feed efficiency, and also human health. We designed an experiment to identify genes associated with accumulation of visceral fat in chickens. Genetic markers developed in these genes can be used to aid selection in order to reduce the accumulation of visceral fat in commercial chickens.
The domestic chicken serves as a major source of high-quality protein for humans. Decades of intensive genetic selection have let to remarkable growth rate and feed efficiency of commercial broiler chickens. However, the rigorous genetic selection for growth rate has led to increased adiposity, skeletal deformities, and disorders of metabolism and reproduction. Excess visceral fat in today's commercial broilers has a negative impact on feed efficiency and also human health maladies. Interrogating the accumulation of visceral fat in commercial chickens with molecular tools will unearth functional genes and pathways that can be manipulated for better feed efficiency and leaner chickens.
High throughput technologies especially RNA-SEQ has provided us with the needed tools to identify genes that underlie traits of economic importance. Messenger RNA expression of important genes regulating visceral fat accumulation in chickens of two divergent lines selected for growth were measured using an integrated microarray system and also RNA-SEQ to evaluate the relative importance of genes in visceral fat development.
Abdominal fat aliquots from forty-eight individuals (4 high-growth and 4 low- growth at 1, 3, 5, 7, 9 and 11 weeks of age) were homogenized for RNA extraction and arrayed on the Del-Mar 14 chicken integrated system microarray (Geo Platform # GPL1731). The same eight RNA samples (4 high-growth and 4 low growth at 7 weeks of age) used for the microarray analysis were also sequences using Illumina platform. The high growth chickens overexpressed many transcription factors and their direct target genes, which should enhance in-situ lipogenesis and ultimately adiposity. Enhanced expression of endocrine-signaling genes in diminished abdominal fat of the low growth chickens provides insight into genetic mechanisms involved in visceral fatness. Genetic markers developed in these genes can assist selection programs to breed for learner chickens.