Oöcyte age sensitive to the diapause hormone from the standpoint of glycogen synthesis in the silkworm, Bombyx mori

Abstract

The weight of the oöcyte-nurse cell complex surrounded with follicle epithelium was conveniently referred to as an approximate oöcyte weight or oöcyte developmental age. Relationships between oöcyte age, glycogen content, and glycogen synthesis in oöcytes were surveyed to explore the diapause hormone action on pupal ovaries. Oöcyte weight did not depend on the presence or absence of the suboesophageal ganglion (SG) or the diapause hormone. Comparing glycogen content in oöcytes of non-diapause type with that of the diapause one, the content of the former was less about 40 per cent than that of the latter, the differences occurring in oöcytes more than 600 μg wt. High incorporation of labelled glucose into oöcyte glycogen fraction started at around 500 μg age, and from this stage the incorporation was fortified strikingly by the SG or the diapause hormone. The diapause hormone does not affect pupal ovaries en bloc but does affect individual oöcytes at about 500 μg age developing successively in pupal ovaries.