ABSTRACT: Erhualian (EHL) is one of the seven strains included in a Chinese indigenous pig breed called Taihu. EHL is famous for its early sexual maturity, large litter size, high adiposity, mild temper, good maternity and high tolerance to roughage and stress.To further investigate the different breed-specific metabolic characters, a comparison of gene expression profile in liver of newborn Erhualian (EHL) and Large White (LW) piglets was carried out. Six niemblegen 135K expression microarrays were used. Among 44,987 pig transcripts investigated, 23,807 transcripts retained for further analysis after removing the probes with poor quality intensities and low dependability.All these qualified transcripts were then annotated by manual blast and by referring to previously developed protein-based annotation for pigs. In total, we observed 9,447 genes expressed in the liver of new born piglets. The microarray data of LW piglets were treated as control in the selection of differentially expressed genes related to EHL piglets. The FDR (False Discovery Rate) and fold change were calculated by SAMR 3.02. With FDR< 5%, after the removal of redundant and unannotated sequences, 53 genes were found to be significantly up-regulated and 200 genes to be significantly down-regulated in the EHL piglets, compared to the LW piglets. With FDR < 10%, 298 genes were found to be significantly up-regulated and 510 genes to be significantly down-regulated in the EHL piglets, compared to the LW piglets. These results were further described in the unpublished paper Coordinated miRNA/mRNA expression profiles for understanding breed-specific metabolic characters of liver between Erhualian and Large White pigs. Six newborn male piglets were sampled from three litters (2 from each litter) of purebred EHL and LW sows and sacrificed. Liver samples were immersed in liquid nitrogen immediately after collection and then stored at -70 M-BM-0C. Total RNA was isolated using the Trizol reagent (Invitrogen, Carlsbad, CA, USA), according to the manufacturerM-bM-^@M-^Ys instructions. Total RNAs of the two littermate piglets were pooled for the microarray analysis. The pooled samples were named as EHL1-3 and LW1-3, representing 3 mixed liver RNA samples each from EHL and LW piglets, respectively. Microarray experiment was performed by a service provider (CapitalBio, Beijing, China). The microarray (Probe length 60-mer, 135K Format) containing 44987 probe sets was provided by Roche-NimbleGen.
