Chemerin is secreted by the chicken oviduct, accumulates in egg albumen and could promote embryo development

Abstract

Understanding of the distribution of chemerin and its receptors, Chemokine-like Receptor 1 (CMKLR1), G Protein-coupled Receptor 1 (GPR1) and Chemokine (C–C motif) receptor-like 2 (CCRL2), in the egg and the embryonic annexes is currently lacking, and their role during embryogenesis remains unknown. By immunoblot using monoclonal anti-chicken antibodies and Enzyme Linked Immunosorbent Assays (ELISA), we found that chemerin is expressed 10 times higher in albumen eggs than in blood plasma, and it is also abundant in the perivitelline membrane but undetectable in yolk. Chicken chemerin can inhibit bacterial growth. By Reverse Transcription—quantitative Polymerisation Chain Reaction (RT-qPCR), western-blot, and immunofluorescence, we show that chemerin is locally produced by the oviduct magnum that participates in albumen formation. Using cultures of magnum explants, we demonstrate that progesterone (P4) and oestradiol (E2) treatment increases chemerin secretion into cultured media and expression in magnum. Chemerin and its three receptors are present in amniotic and Chorio Allantoic Membranes (CAM). Only CMKLR1 expression decreased from embryonic day (ED) 7 to ED11 and remained low until ED18. Chemerin concentrations strongly increased in amniotic fluid at D14 when egg albumen crossed the amniotic membrane. In ovo injections of neutralising chemerin and CMKLR1 antibodies (0.01, 0.1 and 1 µg) increased embryo mortality, which occurred mainly at ED12-13, in a dose-dependent manner. Chemerin treatment increased primary CAM viability. Finally, chemerin and CMKLR1 inhibition within the CAM led to a decrease in blood vessel development and associated angiogenic gene expression. Our results show an important function of the chemerin system during embryo development in chickens, suggesting the potential use of this adipokine as a predictive marker for egg fertility or hatchability.

Chicken white egg chemerin as a tool for genetic selection for egg weight and hen fertility

“…We observed that chemerin concentrations in egg white were significantly higher than in blood plasma and there was no correlation between these two parameters. These data are in good agreement with our previous study ( Estienne et al, 2022 ) showing that chemerin was 10 times more concentrated in egg white than in plasma. In the present study, we developed a specific chicken chemerin ELISA by using specific monoclonal chicken chemerin antibodies and recombinant chicken chemerin.…”

“…Mellouk et al showed that plasma chemerin concentrations were negatively correlated with egg hatchability in chicken ( Mellouk et al, 2018b ). In addition, we also demonstrated an increase of embryo mortality after in ovo injections of anti-chemerin and anti-CMKLR1 antibodies in egg white ( Estienne et al, 2022 ). Thus, our working hypothesis is that chemerin in egg white is involved in the embryo development in chicken and could be a new reproductive trait for genetic selection.…”

“…Moreover, proteomic analyzes have identified chemerin within the albumen and perivitelline membranes of chicken eggs ( Mann, 2007 , 2008 ). Our laboratory recently demonstrated that chemerin is highly present in the albumen compared to the yolk and plasma ( Estienne et al, 2022 ). Moreover in the oviduct of hens, chemerin and its receptors are more expressed in the magnum, where the egg white is formed ( Estienne et al, 2022 ).…”

“…Our laboratory recently demonstrated that chemerin is highly present in the albumen compared to the yolk and plasma ( Estienne et al, 2022 ). Moreover in the oviduct of hens, chemerin and its receptors are more expressed in the magnum, where the egg white is formed ( Estienne et al, 2022 ). Also, a chemerin system is present in extraembryonic membranes such as allantoic and amniotic membranes and fluids suggesting a passage of chemerin from albumen to the extraembryonic membranes ( Estienne et al, 2022 ).…”

“…Moreover in the oviduct of hens, chemerin and its receptors are more expressed in the magnum, where the egg white is formed ( Estienne et al, 2022 ). Also, a chemerin system is present in extraembryonic membranes such as allantoic and amniotic membranes and fluids suggesting a passage of chemerin from albumen to the extraembryonic membranes ( Estienne et al, 2022 ). Mellouk et al showed that plasma chemerin concentrations were negatively correlated with egg hatchability in chicken ( Mellouk et al, 2018b ).…”