Project description:This study integrates global transcriptional profiling and the metabolic perturbation induced by fasting and re-feeding. Genetic control of growth and development should be revealed by systematic modeling of metabolic and regulatory pathways. Chicken oligo arrays were used for transcriptional profiling in two time-course experiments. Two critical developmental stages were chosen: immediately after hatchling (Wk1) and prior to marketing of broiler chickens (Wk6). Only male chickens were used to simplify the experimental design. A RNA reference design was employed for microarray hybridization using two reference RNA pools derived from all individuals sampled at either Wk1 or Wk6. Microarray data was acquired using GenePix Pro software. Loess normalization and a linear mixed model were applied in data processing using the R statistical package with LIMMA software [Smyth, G. K. (2004) Linear models and empirical Bayes methods for assessing differential expression in microarray experiments. Statistical Applications in Genetics and Molecular Biology, Vol. 3, No. 1, Article 3]. The results show hundreds of differentially expressed genes, which are regulated by age and the metabolic perturbation of fasting and re-feeding. Numerous common genes were found at both developmental stages (Wk1 and Wk6) that could be candidates for controlling growth and development of chickens. Differential expression revealed by either microarray or qRT-PCR analyses of selected genes was highly consistent. QRT-PCR verification of genes acutely depressed by fasting includes AGO1, ANGTPL3, ATPCL, FASN, FAT, ME1, PPARG, SCD1, SREBP1 and THRSPA. Genes up-regulated by fasting were ALDOB, IL-15, LDHB, LIPIN2, PANK1, PPARA and UPP2. These genes are functionally assigned to metabolic enzymes, transcription factors, acute phase proteins, immune factors and involved in various pathways (i.e., fatty acid and amino acid metabolism, glycolysis, growth factor signaling and immune defense). Keywords: Hepatic transcripts, oligo-array, chicken, metabolic perturbation, fasting and re-feeding
Project description:To better understand the hepatic metabolic response to intermittent fasting in chickens, Red Junglefowl chickens were raised on ad libitum (AL) feed until 14 days of age and then kept on AL feeding, switched to chronic feed restriction (CR) to around 70% or switched to an intermittent fasting (IF) regimen consisting of two fed days (150% of age-matched weight-specific AL intake offered daily) followed by a non-fed day. AL and CR were culled at 36 days of age, and IF birds either at 40 days of age (second consecutive feeding day) or 41 days of age (fasting day).
Project description:This study integrates global transcriptional profiling and the metabolic perturbation induced by fasting and re-feeding. Genetic control of growth and development should be revealed by systematic modeling of metabolic and regulatory pathways. Chicken oligo arrays were used for transcriptional profiling in two time-course experiments. Two critical developmental stages were chosen: immediately after hatchling (Wk1) and prior to marketing of broiler chickens (Wk6). Only male chickens were used to simplify the experimental design. A RNA reference design was employed for microarray hybridization using two reference RNA pools derived from all individuals sampled at either Wk1 or Wk6. Microarray data was acquired using GenePix Pro software. Loess normalization and a linear mixed model were applied in data processing using the R statistical package with LIMMA software [Smyth, G. K. (2004) Linear models and empirical Bayes methods for assessing differential expression in microarray experiments. Statistical Applications in Genetics and Molecular Biology, Vol. 3, No. 1, Article 3]. The results show hundreds of differentially expressed genes, which are regulated by age and the metabolic perturbation of fasting and re-feeding. Numerous common genes were found at both developmental stages (Wk1 and Wk6) that could be candidates for controlling growth and development of chickens. Differential expression revealed by either microarray or qRT-PCR analyses of selected genes was highly consistent. QRT-PCR verification of genes acutely depressed by fasting includes AGO1, ANGTPL3, ATPCL, FASN, FAT, ME1, PPARG, SCD1, SREBP1 and THRSPA. Genes up-regulated by fasting were ALDOB, IL-15, LDHB, LIPIN2, PANK1, PPARA and UPP2. These genes are functionally assigned to metabolic enzymes, transcription factors, acute phase proteins, immune factors and involved in various pathways (i.e., fatty acid and amino acid metabolism, glycolysis, growth factor signaling and immune defense). A reference RNA design was used for microarray hybridizations, where the same reference RNA pool was co-hybridized to each target sample on an microarray. The reference RNA pool was made from an equal amount of high-quality amplified RNA (aRNA), derived from all liver samples within each experiment (Wk1 = 50 samples and Wk6 = 30 samples). The reference RNA pool was labeled with Alexa 647 while each target sample was labeled with Alexa 555.
Project description:In the present study, we examined the hepatic transcriptome of chickens during the peri-hatch period—or the metabolic jump from chorioallantoic (embryo) to pulmonary (hatchling) respiration. Although our major interest was comparison of differentially-expressed genes between embryos and hatchlings, we made pairwise contrasts across six developmental ages. We collected the liver from four embryos at three ages (e16, e18 and e20) and four hatchling chicks at three ages (1, 3 and 9 days) post hatching. Liver samples (N=24) were used for extraction of total RNA which was then used for hybridization to 24 Affymetrix Chicken Genome Arrays. Ingenuity Pathways Analysis was used for functional annotation and mapping of differentially expressed (FDR≤0.05) genes to canonical pathways and gene interaction networks. We identified 1274 hepatic genes that were differentially expressed between embryos and hatchling chicks and of these, 284 genes are involved in lipid metabolism. The three most abundant found in liver of embryos were (MOGAT1, DIO3 and PDK4), whereas THRSP, FASN and DIO2 were greatly expressed in liver of hatchlings. Two functionally-distinct clusters of hepatic genes have emerged from our time-course transcriptional scans in the peri-hatch chicken. Cluster A genes are largely lipolytic with higher expression in the embryo, while Cluster B genes are mainly lipogenic and thermogenic with greater expression in liver of hatchlings. The present study describes the innate chorography of transcriptional responses of liver to the abrupt metabolic switch from aquatic ectothermy (embryos) to free-living endothermy (hatchling chicks).
Project description:One of the key functions of the mammalian liver is lipid metabolism. During fasting, lipid storage in the liver increases in order to reserve and provide energy for cellular functions. Upon re-feeding, this reserve of lipids is rapidly depleted; this change is visible, as the organelles responsible for lipid storage – lipid droplets (LDs) – drastically decrease in size following re-feeding. Little is known regarding LD proteome, or how it changes during the fasting/re-feeding transition. Our study investigated the hepatic LD proteome and how it changes between fasting and re-feeding conditions. For this purpose, LDs were isolated from 4 month-old C57BL/6 mice after a 24 hour fasting period, or a 24 hour fasting period followed by 6 hours of re-feeding. Proteins isolated from these LDs were subject to SDS-PAGE followed by in-gel trypsinization and LC-MS/MS. We identified a combined total of 941 proteins on hepatic LDs, of which 817 had quantifiable extracted ion chromatograms in at least 2 samples (n=6 total) and were not deemed contaminants. 777 of the 817 proteins were observed in both energetic states, with 33 being uniquely observed in fasted LDs, and 7 being uniquely observed in re-fed LDs.
Project description:We investigated the effects of heat stress on the liver transcriptome of 3wk-old chicks of a broiler line, the Fayoumi and an advanced intercross line (AIL). Transcriptome sequencing of 48 male chickens using Illumina HiSeq 2500 technology yielded an average of 3.4 million, 100-base -pair single-end, reads per sample.
Project description: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. Experiment 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.
Project description:This SuperSeries is composed of the following subset Series: GSE13060: The effects of temporally restricted feeding on hepatic gene expression GSE13062: The effects of temporally restricted feeding on hepatic gene expression of Cry1, Cry2 double KO mice GSE13063: Effects of extensive fasting and subsequent feeding on hepatic transcription GSE13064: Effects of extensive fasting on hepatic transcription Refer to individual Series