Biomaterial Database

RNA-sequencing analysis of shell gland shows differences in gene expression profile at two time-points of eggshell formation in laying chickens. 2019

Samiullah Khan, and Shu-Biao Wu, and Juliet Roberts

Animal Science, School of Environmental and Rural Science, University of New England, Armidale, New South Wales, 2351, Australia.

BACKGROUND Eggshell formation takes place in the shell gland of the oviduct of laying hens. The eggshell is rich in calcium and various glycoproteins synthesised in the shell gland. Although studies have identified genes involved in eggshell formation, little is known about the regulation of genes in the shell gland particularly in a temporal manner. The current study investigated the global gene expression profile of the shell gland of laying hens at different time-points of eggshell formation using RNA-Sequencing (RNA-Seq) analysis. RESULTS Gene expression profiles of the shell gland tissue at 5 and 15 h time-points were clearly distinct from each other. Out of the 14,334 genes assessed for differential expression in the shell gland tissue, 278 genes were significantly down-regulated (log2 fold change > 1.5; FDR < 0.05) and 413 genes were significantly up-regulated at 15 h relative to the 5 h time-point of eggshell formation. The down-regulated genes annotated to Gene Ontology (GO) terms showed anion transport, synaptic vesicle localisation, organic anion transport, secretion and signal release as the five most enriched terms. The up-regulated gene annotation showed regulation of phospholipase activities, alanine transport, transmembrane receptor protein tyrosine kinase signalling pathway, regulation of blood vessels diameter and 3, 5-cyclic nucleotide phosphodiesterase activity as the five most enriched GO terms. The putative functions of genes identified ranged from calcium binding to receptor activity. Validation of RNA-Seq results through qPCR showed a positive correlation. CONCLUSIONS The down-regulated genes at 15 h relative to the 5 h time-point were most likely involved in the transport of molecules and synthesis activities, initiating the formation of the eggshell. The up-regulated genes were most likely involved in calcium transportation, as well as synthesis and secretory activities of ions and molecules, reflecting the peak stage of eggshell formation. The findings in the current study improve our understanding of eggshell formation at the molecular level and provide a foundation for further studies of mRNA and possibly microRNA regulation involved in eggshell formation in the shell gland of laying hens.

UI	MeSH Term	Description	Entries
D010057	Oviducts	Ducts that serve exclusively for the passage of eggs from the ovaries to the exterior of the body. In non-mammals, they are termed oviducts. In mammals, they are highly specialized and known as FALLOPIAN TUBES.	Oviduct
D002645	Chickens	Common name for the species Gallus gallus, the domestic fowl, in the family Phasianidae, order GALLIFORMES. It is descended from the red jungle fowl of SOUTHEAST ASIA.	Gallus gallus,Gallus domesticus,Gallus gallus domesticus,Chicken
D004528	Egg Shell	A hard or leathery calciferous exterior covering of an egg.	Eggshell,Egg Shells,Eggshells,Shell, Egg,Shells, Egg
D005260	Female		Females
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D016000	Cluster Analysis	A set of statistical methods used to group variables or observations into strongly inter-related subgroups. In epidemiology, it may be used to analyze a closely grouped series of events or cases of disease or other health-related phenomenon with well-defined distribution patterns in relation to time or place or both.	Clustering,Analyses, Cluster,Analysis, Cluster,Cluster Analyses,Clusterings
D017423	Sequence Analysis, RNA	A multistage process that includes cloning, physical mapping, subcloning, sequencing, and information analysis of an RNA SEQUENCE.	RNA Sequence Analysis,Sequence Determination, RNA,Analysis, RNA Sequence,Determination, RNA Sequence,Determinations, RNA Sequence,RNA Sequence Determination,RNA Sequence Determinations,RNA Sequencing,Sequence Determinations, RNA,Analyses, RNA Sequence,RNA Sequence Analyses,Sequence Analyses, RNA,Sequencing, RNA
D059467	Transcriptome	The pattern of GENE EXPRESSION at the level of genetic transcription in a specific organism or under specific circumstances in specific cells.	Transcriptomes,Gene Expression Profiles,Gene Expression Signatures,Transcriptome Profiles,Expression Profile, Gene,Expression Profiles, Gene,Expression Signature, Gene,Expression Signatures, Gene,Gene Expression Profile,Gene Expression Signature,Profile, Gene Expression,Profile, Transcriptome,Profiles, Gene Expression,Profiles, Transcriptome,Signature, Gene Expression,Signatures, Gene Expression,Transcriptome Profile
D020869	Gene Expression Profiling	The determination of the pattern of genes expressed at the level of GENETIC TRANSCRIPTION, under specific circumstances or in a specific cell.	Gene Expression Analysis,Gene Expression Pattern Analysis,Transcript Expression Analysis,Transcriptome Profiling,Transcriptomics,mRNA Differential Display,Gene Expression Monitoring,Transcriptome Analysis,Analyses, Gene Expression,Analyses, Transcript Expression,Analyses, Transcriptome,Analysis, Gene Expression,Analysis, Transcript Expression,Analysis, Transcriptome,Differential Display, mRNA,Differential Displays, mRNA,Expression Analyses, Gene,Expression Analysis, Gene,Gene Expression Analyses,Gene Expression Monitorings,Gene Expression Profilings,Monitoring, Gene Expression,Monitorings, Gene Expression,Profiling, Gene Expression,Profiling, Transcriptome,Profilings, Gene Expression,Profilings, Transcriptome,Transcript Expression Analyses,Transcriptome Analyses,Transcriptome Profilings,mRNA Differential Displays