A Diurnal Change in the Amount of Nucleic Acids in the Testis of Immature Cockerels

The amount of RNA in the testis of immature cockerels has been shown to increase by the injection of pituitary gonadotropins1). The gonadotropic activity of the anterior pituitary of cockerels has been known to show a diurnal change starting at 5 weeks of age2). White Leghorn cockerels were housed in cages under 14hr light (5.00-19.00 hours) per day with food and water available continuously. Four week and 7 week old birds were killed by decapitation at the nine different times during a 24hr period: 8.00, 11.00, 14.00, 16.00, 18.00, 21.00, 0.00, 2.00 and 5.00 hours. Five or 8 birds were killed at each time and their testes were removed, frozen immediately on dry ice and stored