Abstract: To investigate the differential expression of soluble protein components, the soluble protein components of male and female eggs in the period of ji3 in Bombyx mori variety ‘W-1’ were compared by two-dimensional electrophoresis technology. The results showed that 317 and 335 protein spots were detected in soluble proteins of male and female egg respectively. Comparison analysis showed that 273 of the total protein spots were matched between male and female egg, and 44 and 62 specific protein spots were found in male and female egg respectively. The results indicated that soluble protein components in the period of ji3 in silkworm were different between the male and female. The characteristic protein spots were identified by MALDI-TOF MS. The result showed that proteins identified were putative keratin, tropomyosin isoform 5, RNA binding protein encoded by Sqd gene, transgelin, heat shock protein 20.4 and tropomyosin 1, indicating that gender has an important influence on the formation of embryonic organs and tissues．

Key words: Bombyx mori, Ji3, W-1, soluble protein, 2D-etectrophoresis