Investigation of gender differences in the incidence of ascites and profile of gene expression in kidney tissue of broiler chickens

Ascites syndrome is one of the most important causes of death in the poultry industry, in which various tissues of the body, including the kidneys, are involved. This syndrome occurs with different frequencies in males and females, and different mechanisms of ascites in the two sexes have not been studied to date. In this study, the gene expression profile of kidney tissue of male and female chickens with ascites syndrome from the paternal line (B) of the Arian commercial line was compared using RNA-Seq data. Due to severe cold stress applied, the mortality rate was high and about 59%, which was higher in males (63.4%) than females (54.1%). The results of transcriptome analysis showed that 240 genes were significantly different in comparison between ascites male and female birds. The annotation analysis of these genes showed that the metabolic pathways of antibiotic biosynthesis and amino acids, carbon metabolism, cell adhesion, receptor-extracellular matrix interaction (ECM) were involved in this process. The body's response to ascites-induced damage to kidney tissue is the development of renal fibrosis (to repair the damage) and reduced activity of the glycolysis pathways and increased gluconeogenesis to reduce energy and oxygen consumption in these pathways. Furthermore, an increase of the STAT-JAK2 signaling pathway activity (due to the high expression of JAK2 and STAT3 genes) was observed. This signal stimulates cell growth, angiogenesis, differentiation, migration, and apoptosis. It is expected that the results of the present study to provide new insights into understanding the molecular mechanism of ascites incidence and also differences in its occurrence in males compared to female broiler chickens.