Figure 1

The Foetal Testis Assay (FeTA) as a usefull tool to measure the effects of Endocrine Disruptors. Foetal Testis Assay (FeTA) was developed by our laboratory for rat, mouse and human species [47, 103–108, 126]. Human, rat or mouse foetal testes are cut in small pieces of a volume of about 0.2 mm³/each piece, at all developmental stages and in all studied species. One to four pieces are randomly placed on Millicell-CM Biopore membranes (pore size 0.4 μm, Millipore, Billerica, MA) floating on 320 μL culture medium in tissue culture dishes. One to eight wells per testis are thus prepared, depending on the species and the age at explantation. The culture medium is phenol red-free Dulbecco modified Eagle medium/Ham F12 (1:1) without addition of any biological factor or hormone. Testes are cultured at 37°C in a humidified atmosphere containing 95% air/5% CO₂ for three or four days. Medium is completely changed every 24 h. The androgenic and masculinizing activities of cultured testes are evaluated based on the amount of testosterone that is secreted daily by foetal Leydig cells of each testis, on the total number of foetal Leydig cells per testis, or the expression of Leydig cell markers (steroidogenic enzymes or actors, INSL3, LH Receptors).