Effect of Glyphosate based herbicide on ovarian chicken transcriptome

Glyphosate-based herbicides (GBHs) formulations are pesticides massively used in agricultural and EU decided to extend the use of GLY in Europe until 2034. Recently, we showed that chronic dietary exposure to GBH in adult hen resulted in reversible increase chicken early embryo mortality. Here, we investigated the GBH effects on metabolic and ovarian effects by using transcriptomic approaches in in vivo young broiler chicken and in vitro explants cultures. In our protocol, female broilers (11 days-old) were dietary exposed to two GBH concentrations (13 (GBH-, n=20) and 34 (GBH+, n=20) mg/kg-1/day-1 glyphosate equivalent corresponding to approximately one eighth and one third of the No-Observed-Adverse-Effect-Level (NOAEL) as defined by European Food Safety Authority in birds, or not (Control group (CT), n = 20) for 2 weeks. During this period, we first investigated the consequences on the body weight, fattening, food intake and the weight of some organs including ovary. Chronic dietary exposure to GBH reduced in dose dependent manner food intake, body weight and fattening whereas it increased the oxidative stress and relative weight of ovary in relation to body weight. We next analyzed the ovarian gene expression profile in CT, GBH- and GBH+ animals by RNA-seq and we showed that differentially expressed genes were mainly enriched in pathways related to cholesterol metabolic and steroidogenesis processes and RNA processing. By RTqPCR and western-blot we confirmed that GBH decreased ovarian STAR and CYP19A1 mRNA and protein expression, respectively. Furthermore, we confirmed that GBH altered steroid production in ovarian explants. Our study obtained ovarian transcriptomic data from chicken chronic GBH dietary exposed and identified potential regulatory networks associated with GBH. This data provides valuable support for understanding the ovarian transcriptional regulatory mechanism of GBH in growing broilers.