Differential gene expression profiling of the goose pineal gland

1. The present study was conducted to obtain a better understanding of the molecular mechanisms underlying broodiness in a commercial breed, Tianfu geese, as little is known about the role of the pineal gland in this period. The aim was to identify genes which are differentially expressed in the pineal gland between the laying and broodiness periods by performing a transcriptome screen.2. After sequencing cDNA derived from the pineal gland and annotation of the results, a sequencing depth of 14.82 and 18.17 million mapped tags was obtained during the laying and broodiness periods, respectively, and a total of 120 differentially expressed genes were identified. Of these, 32 genes showing up-regulated expression and 88 genes showing down-regulated expression were identified in broodiness period vs. laying period libraries.3. Gene ontology (GO) analyses showed that these genes were related to the visual process, phototransduction, and lipoprotein metabolism. Kyoto Encyclopaedia of Genes and Genome (KEGG) analyses showed that phototransduction and tryptophan metabolism pathways exhibited the largest enrichment factors. The reliability of the RNA sequence data was confirmed by quantitative real-time PCR analysis of five genes, and the results were mostly consistent with those from the high-throughput RNA sequencing.4. The goose transcriptome and the identification of differentially expressed genes provided comprehensive gene expression information that enables a better understanding of the molecular mechanisms underlying the broodiness period of geese.