IDENTIFICATION DES FACTEURS PHYSIOLOGIQUES CONTROLANT LE POLYPENISME PHASAIRE CHEZ LE CRIQUET MIGRATEUR ( IDENTIFICATION OF PHYSIOLOGICAL FACTORS RESPONSIBLE FOR PHASE POLYMORPHISM OF MIGRATORY LOCUST )

The gregarization in the migratory locust, Locusta migratoria and its trans-generational characteristic were controlled by the maternal gregarizing factor which secreted in the egg pod foam by the female's accessory glands. The comparison by SDS-PAGE of the contents of these glands showed the presence of a supplementary proteic band specific of gregarious phase with a molecular weight 30 KDa, absent in the solitary phase. The synthesis of the maternal gregarization factor was determined in gregarious accessory glands under the control of another factor, obtained by SDS-PAGE in the haemolymph of gregarious females. The trans-generational specificity of the maternal gregarizing factor was revealed in the presence in gregarious oocytes of a protein band of the same molecular weight (30 KDa) as that observed in the accessory glands. Analysis of gregarious egg pod foam by Thin Layer Chromatography showed the presence of a supplementary spot. No solitary phase specific spots were obtained in solitary foam matter. In gregarious eggs, a proteic band of molecular weight 263 KDa exists throughout the first 6 days of embryonic life. It disappeared since the first day in solitary phase. Gregarious hatchlings also showed a difference in the proteins content of their haemolymph; a proteic band of molecular weight of 66 KDa was observed in gregarious phase, absent in solitary one.These results prove that gregarious egg pod foam represents a physiological transporter of the maternal gregarizing factor from the female accessory glands to oocytes.