CELLULAR DIFFERENCES IN RING GLANDS OF FLESH FLY PUPAE AS A CONSEQUENCE OF DIAPAUSE PROGRAMMING

Citation
Kh. Joplin et al., CELLULAR DIFFERENCES IN RING GLANDS OF FLESH FLY PUPAE AS A CONSEQUENCE OF DIAPAUSE PROGRAMMING, Tissue & cell, 25(2), 1993, pp. 245-257
Citations number
39
Categorie Soggetti
Cytology & Histology
Journal title
ISSN journal
00408166
Volume
25
Issue
2
Year of publication
1993
Pages
245 - 257
Database
ISI
SICI code
0040-8166(1993)25:2<245:CDIRGO>2.0.ZU;2-T
Abstract
The ultrastructure of the ring gland (corpus cardiacum (CC), prothorac ic gland (PG) and corpus allatum (CA)) was examined in diapausing and nondiapausing flesh fly pupae. The diapause developmental state, which is environmentally regulated and coordinated by the brain-ring gland complex, is associated with differences in the ultrastructure of PG an d CA cells but not in the CC. During diapause the PG and CA cells have extensive arrays of rough endoplasmic reticulum and spherical mitocho ndria. The PG cells also contain lipid droplets surrounded by an elect ron dense amorphous coat not seen in PG cells from nondiapausing pupae . In nondiapausing pupae, the PG and CA cells contain large amounts of ribosomes throughout the cytoplasm but very little rough endoplasmic reticulum and elongated mitochondria. The fact that ring glands from d iapausing pupae readily incorporate S-35-methionine indicates that the gland is actively synthesizing proteins, thus the contrasts in ring g land ultrastructure are not due to cellular quiescence during diapause but reflect fundamental cellular and physiological differences betwee n the diapause and nondiapause developmental program.