Transcriptome analysis of the bursa of Fabricius and thymus of laying ducks reveals immune gene expression changes underlying the impacts of stocking densities.

1. The thymus and bursa of Fabricius are important immune organs in poultry as they play essential roles in sustaining the normal immune function to maintain health. The following trial investigated whether the stocking density affected gene expressions in immune organs.2. Jinding ducklings were raised in either low or high density (4 or 8 birds/m2) conditions from four to 14 weeks of age, and were then slaughtered and tissues removed. Samples were subjected to high-throughput sequencing to sequence RNA extraction. After filtering calculations with R software, a total of 508 (thymus) and 1,356 (bursa of Fabricius) differentially expressed genes (DEGs) were identified, suggesting that stocking density has an effect on gene expression in duck immune organs.3. Out of a total of 112 immune factor genes and 112 immune pattern receptor genes in ducks, four thymus and 18 bursa of Fabricius genes were differentially expressed in ducks, which indicated that the change of stocking density could affect the expression of immune genes in poultry.