INVOLVEMENT OF A MATERNALLY TRANSCRIBED LECTIN GENE IN THE EARLY DEVELOPMENT OF BOMBYX-MORI

The expression of a lectin gene was investigated during oogenesis and embryonic development of the silkworm, Bombyx mori. During oocyte development, the Bombyx 50 kDa lectin gene was transcribed in the nurse cells, the transcripts were transferred through the ring canal from the nurse cell cytoplasm to the ooplasm, and were deposited in the ooplasm cortex. In unfertilized eggs the transcripts were restricted to the cortex, the site of formation of cells in the embryo. In early embryos the transcript and its products only accumulated in the serosa cell cytoplasm and little of the lectin was deposited in other egg regions such as the germ-band. These patterns of localization suggest that this lectin plays a part in serosa formation in early embryogenesis in a maternal effect manner.