Measurement of Volume Changes in the Nucleus and Nucleolus of Sarcophaga Bullata (Diptera: Sarcophagidae).

Abstract

Nuclei and nucleoli of the dorsal giant cells of metathoracic pulvilli of the fleshfly S. bullata underwent volume fluctuations during development. Such fluctuations reflect the functions and synthetic activity of cells. Nuclear volume increased with development of the adult pulvillus and maximal volumes were recorded between 122 and 288 h. Between 288 and 300 h nuclear volume decreased, and the cells become pycnotic just before adult emergence. Nucleoli showed maximal volumes at 115 h. Between 140 and 192 h, the period of intense sequential secretion of cuticle, nucleoli assumed a granular irregular appearance, in contrast to the spheroidal and vacuolated structure observed at other times. Nuclei and nucleoli from outside cells were always the largest.