Project description:Purpose: With the advent of Next-generation sequencing (NGS), several novel genes/proteins and cellular pathways in wide variety of tissues has been discovered. The aim of this study are to perform uterine transcriptome profiling (RNA-seq) to determine differently expressed genes in laying and non-laying hens and to further validate the expression of candidate genes using real-time quantitative reverse transcription polymerase chain reaction (qRT–PCR) in laying, non-laying and molting hens. Methods: Uterine mRNA profiles of 35-60 weeks-old laying and non-laying hens, three each, were generated with NextSeq 500 sequencer in single-end mode with a read length of 1x76 bp. Raw sequencing reads were cleaned and trimmmed with Prinseq tool and good reads were aligned against the chicken reference gemone (Galgal 5.0) in Array Studio. Differential gene expression analysis was performed by the DESeq2 algorithm as implemented in Array Studio. The genes with at least two-fold change (FC) and Benjamini and Hochberg q-value < 0.05 were called differentially expressed. Results: Using an optimized data analysis workflow, we mapped about 32 million reads from layers and 28 million reads from non-layers to the chicken genome. A total of 19,152 gene transcripts were annotated from Ensembl alignment which represents 50.24% of the chicken genome assembly. Differential gene expression analysis showed 616 were differentially expressed between layer and non-layer hens. 229 DEGs were significantly up-regulated and 286 were significantly down-regulated in the laying hens when compared to the non-laying hens. Twelve candiate genes, linked to calcium remodeling, were identified by gene function analysis and validated using qPCR. MEPE, CALCB, OTOP2, STC2 and ATP2C2 were confirmed to be highly expressed in laying hens as compared to molting and non-laying hens. RNA-seq and qPCR data for relative gene expression were highly correlated (R2 =0.99). Conclusions: Our study reports the expression of four novel genes that are speculated to transport calcium ions across the uterine epithellium for eggshell mineralization. These genes can be used as quantitative basis of selecting hens with an improved eggshell quality.
Project description:Purpose: With the advent of Next-generation sequencing (NGS), several novel genes/proteins and cellular pathways in wide varitey of tissues has discovered. The aim of this study are to perform transcriptome profiling (RNA-seq) of magnum to determine differently expressed genes in laying and non-laying hens and to further validate the expression of candidate genes using real-time quantitative reverse transcription polymerase chain reaction (qRT–PCR) in laying, non-laying and molting hens. Methods: Magnum mRNA profiles of 35-60 weeks-old laying and non-laying hens, three each, were generated with NextSeq 500 sequencer in single-end mode with a read length of 1x76 bp. Raw sequencing reads were cleaned and trimmmed with Prinseq tool and good reads were aligned against the chicken reference gemone (Galgal 5.0) in Array Studio. Differential gene expression analysis was performed by the DESeq2 algorithm as implemented in Array Studio. The genes with at least three-fold change (FC) and Benjamini and Hochberg q-value < 0.05 were called differentially expressed. Results: Using an optimized data analysis workflow, we mapped about 30.5 million reads from layers and 33.4 million reads from non-layers to the chicken genome. A total of 19,152 gene transcripts were annotated from Ensembl alignment which represents 50.24% of the chicken genome assembly. Differential gene expression analysis showed 540 were differentially expressed between layer and non-layer hens. 152 DEGs were significantly up-regulated and 388 were significantly down-regulated in the laying hens when compared to the non-laying hens. Conclusions: Our study reports the expression of several pre-discovered and many novel genes that may be involved in the transport of precurosor molecules for biosynthesis and secretion of the egg-white proteins in the magnum. These genes can be used as quantitative basis of selecting hens with an improved egg quality.
Project description:Overfeeding reduces laying performance in broiler breeder hens (Gallus gallus domesticus). To unravel the effect of feeding regimes on energy metabolism and egg production, high-throughput RNA sequencing was utilized to identify differentially expressed genes (DEGs) in ovary, liver and adipose tissues of broiler chickens under ad libitum and restricted feeding. The transcriptome analysis showed that 289, 388 and 204 DEGs were identified in the adipose tissue, liver and ovary, respectively, between ad libitum and restricted feeding groups. Bioinformatics analysis by STRING further revealed DEGs were significantly enriched in phagosome pathway, lipid transport and location biological process, and the molecular function of lipid transporter activity and nutrient reservoir activity in ovary; the pathways of “steroid hormone biosynthesis” and “metabolism of xenobiotics by cytochrome P450”, and the molecular function of nutrient reservoir activity in adipose tissue; the metabolic pathways, Jak-STAT signaling pathway and PPAR signaling pathway in liver.
Project description:Ovarian cancer has a high mortality rate due, in part, to the lack of early detection and incomplete understanding of the origin of the disease. The hen is the only spontaneous model of ovarian cancer, and can therefore aid in the identification and testing of early detection strategies and therapeutics. To our knowledge, no studies to date have examined global gene expression in ovarian cancer of the hen. Our aim was to combine the use of the hen animal model and microarray technology to identify differentially expressed genes in ovarian tissue from normal hens compared to hens with ovarian cancer. Ovarian tissue samples from whole ovaries were collected from hens for RNA extraction and hybridization on Affymetrix microarrays. Hens were matched for age and laying status. Normal hens (n=3) showed no gross or histopathological evidence of ovarian cancer, while cancer specimens (n=3) had tumors that were stage 2 (restricted to the ovary and observable at necropsy) or 3 (ovarian tumor with abdominal seeding). Total RNA was extracted using TRIZOL according to the manufacturer's instructions.
Project description:Liver tissues of Guangxi Ma chicken from 32-week old with m performance, 50-week old with high and low laying performance, and 72-week old with high and low laying performance were collected and sequenced in quadruplicate using RNA-seq. The sequences were double-ended sequenced on the DNBSEQ sequencing platform. The sequence reads were quality controlled and then aligned with genomic sequences using HISAT2 program, quantified by featureCounts program, and gene expression levels were verified by qRT-PCR with SYBR Green detection. The results will be helpful to explore the factors that affecting laying performance from the perspective of yolk synthesis and provide a theoretical basis for improving the egg production of Guangxi Ma chicken.
Project description:Calcium (Ca) and phosphorus (P) are essential micronutrients that are linked to a wide set of biological processes. In laying hens there is still uncertainty about the optimal Ca/P ratio in feed and further strategies for the reliable mineral restriction in poultry diets are required. The dataset is based on Lohmann Selected Leghorn (LSL) and Lohmann Brown (LB) laying hens sampled at peak performance. The experimental design comprises four dietary groups differed in Ca (recommended vs. 15 % reduction) and mineral P (adequate vs. 20 % reduction) levels; 1) control diet (Con; Ca=34.4g/kg, P=5.3 g/kg and Ca/P ratio=7.45), 2) Low Ca and P diet (LCaP), 3) low Ca diet (LCa), and low P diet (LP). Jejunal transcriptome profiles were assessed by mRNA sequencing in a total of 80 animals (10 hens per experimental group for each laying line) at sampling age of 31 weeks) to approximate the consequences of variable Ca and P supply.
Project description:Our study investigated the differences of uterine transcriptome in laying hen holding a high or low breaking strength shell. The eggshell calcification periods are divided into three periods, namely initiation, growth and termination periods respectively. The large differences in the transcriptome proved that the initiation period of calcification determine eggshell strength.
Project description:In this study, RNA-Seq technology was adopted to investigate the differences in expression profiles of the hepatic lipid metabolism-related genes and the associated pathways between juvenile and laying hens. RNA-Seq analysis was carried out to estimate total RNA harvested from the liver of juvenile hens (n = 3) and laying hens (n = 3). Compared with juvenile hens, 2574 differentially expressed (DE) genes (1487 down and 1087 up) with P ⤠0.05 were obtained, and 955 of these genes were significantly DE (SDE) at a false discovery rate (FDR) of 0.05 and fold-change ⥠2 in laying hens. There were 198 SDE novel genes (107 down-regulated and 91 up-regulated) (FDR ⤠0.05) that were obtained from the transcriptome, and most of them were highly expressed. Moreover, 332 SDE isoforms were identified. Gene Ontology (GO) enrichment and KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway analysis showed that SDE genes were significantly associated with steroid biosynthesis, PPAR signaling pathway, biosynthesis of unsaturated fatty acids, glycerophospholipid metabolism, three amino acid pathways, and pyruvate metabolism (P ⤠0.05). The top significantly enriched GO terms included lipid biosynthesis, cholesterol and sterol metabolic, and oxidation reduction suggesting the principal lipogenesis in the liver of laying hens. This study suggests that the major changes at the level of transcriptome in laying hen liver are closely related to fat metabolism. Some highly differentially expressed uncharacterized novel genes and alternative splicing isoforms detected might also take part in lipid metabolism, though it needs investigation. Therefore, this study provides valuable information of mRNA of chicken liver, and deeper functional investigations on the mRNAs could help explore or provide new insights into molecular networks of lipid metabolism in chicken liver. The liver expression profile of juvenile hens and laying hens were generated by RNA-seq.
Project description:Ovarian follicle selection plays an important role in the reproduction of sexually mature hens, and this process can directly affect the growth and development of follicles until the final ovulation, thus affecting laying performance and fecundity of hens. In the laying hen ovary, one follicle from a cohort of 8-13 follicles of 6-8 mm in diameter is selected daily to enter the preovulatory hierarchy. In this study, we globally compared the proteomes of chicken ovarian follicles before and after follicle selection. A total of 5883 proteins were identified in the proteomes of chicken 6-8 mm prehierarchical follicles and 12-15 mm hierarchical follicles. 259 proteins are differentially expressed in 12-15 mm hierarchical follicle compared with prehierarchical follicle, of which 175 proteins are up-regulated and 84 proteins are down-regulated. The Gene Ontology enrichment of differentially expressed proteins revealed enriched GO terms for peptidase activity, acrosin binding for their molecular function and in the process of negative regulation of peptidase activity, and regulation of fertilization. The KEGG pathway analysis indicated that differentially expressed proteins were enriched for ribosome, lysine degradation, and endocytosis pathways. Nine differentially expressed proteins including vitellogenin-1 were validated with Parallel Reaction Monitoring (PRM) analysis, and their functions were discussed. This study provided a global proteomic view of the development of chicken ovarian follicles, which will serve as a foundation for understanding the molecular signatures and pathways of follicle selection in hens.