VMO1 (Vitelline Membrane Outer layer protein 1) and AvBD11 (Avian Beta-Defensin 11, formerly known as VMO2) are two egg proteins, particularly abundant in the proteinaceous structure surrounding the egg yolk, namely the outer vitelline membrane. Both proteins are expressed in the oviduct and secreted into the forming egg. AvBD11 is likely involved in egg immunity, while the biological function of VMO1 still remains unknown. It is thought that these proteins might also play structural roles in contributing to the integrity of the vitelline membrane. Indeed, as the vitelline membrane weakens during egg storage at 20°C, protein levels of VMO1 and AvBD11 are known to decrease in the vitelline membrane, suggesting that they are potential biomarkers of quality of the vitelline membrane. In this work, our aim was to investigate (i) the expression pattern of VMO1 and AvBD11 genes in different hen tissues and (ii) the effects of hen age on the expression profile of these genes in the oviduct. In a first experiment, gene expression was analyzed by RT-qPCR in reproductive tissues including the oviduct (infundibulum, magnum, white isthmus, uterus, vagina) and the ovary (theca, granulosa), and in non-reproductive tissues (bone marrow, skin, lung, duodenum, kidney, liver) from laying hens. Our results demonstrated that VMO1 and AvBD11 genes are mainly expressed in the oviduct, while no or very low expression is detected in the other tissues analyzed. The magnum (involved in the secretion of albumen) is the oviductal region showing the strongest expression for both genes. These genes are also expressed but at lower levels, in other parts of oviduct, namely the infundibulum (secretion of outer vitelline membrane) for VMO1 and AvBD11, and the white isthmus (eggshell membranes) for AvBD11. Our data thus suggest that VMO1 and AvBD11 are presumably two egg-specific proteins. These expression sites are consistent with the presence of these proteins in egg albumen and vitelline membrane. Considering that the quality of these two latter egg structures is altered by hen age, especially in late laying cycle, a second experiment was conducted in which tissues sampled from the upper oviduct (responsible for the secretion of albumen and vitelline membrane) were collected from laying hens at three periods of egg production (32-34, 73-75 and 99-100 weeks of age). RT-qPCR analysis of VMO1 and AvBD11 genes in these tissue samples is in progress.