Transcriptomic analysis of liver in sex-linked Dwarf and wild type chickens. Gallus gallus

The sex-linked Dwarf (SLD) recessive mutation is characterized by a significant reduction of body size in hemizygous females (30%) and homozygous males (40%). The SLD chickens of the Leghorn line are affected by a Growth Hormone (GH) resistance condition due to a missense mutation at the Growth Hormone Receptor (GHR) gene causing a loss of function of the GHR. The sex-linked recessive dwarf mutation has large commercial use in maternal lines of the broiler poultry industry since these hens require less food and less housing space. The SLD chickens are also an interesting model for investigating complex traits such as energy expenditure and heat resistance for which the SLD chickens differ compared to normal size ones. In this study we performed a whole genome microarray expression profiling of liver using a 8x60K custom Agilent microarray. In total we analyzed 24 SLD and 24 wild type birds of 12 weeks of age obtained by crossing a heterozygous “dw” Leghorn cock with 12 females of an inbred Leghorn line to obtain wild type and dwarf sib and half-sib hens. The aim of the study was the fine identification of GH-inducible genes, and the characterization of the GH dependent signalling pathways. Overall design: A population of Leghorn hens was created by crossing a heterozygote cock Dw/dw with 12 normal Leghorn females to obtain normal (Dw/-)and dwarf (dw/-) sisters and half sisters. In total we analyzed the liver trascriptomic profile from 24 SLD and 24 wild type birds at 12 weeks of age (Wks).