PROTEIN UPTAKE INTO MULTIVESICULAR BODIES AND STORAGE GRANULES IN THE FAT BODY OF AN INSECT
Open Access
- 1 March 1968
- journal article
- research article
- Published by Rockefeller University Press in The Journal of cell biology
- Vol. 36 (3), 453-483
- https://doi.org/10.1083/jcb.36.3.453
Abstract
The fat body in Calpodes ethlius (Lepidoptera, Hesperiidae) takes up protein from the blood throughout the larval stage before pupation. Depending upon the phase of development, the protein appears in multivesicular bodies, in large storage granules, and in structures of intermediate form. There are three phases in the 8 days of the last larval stage; the first devoted to growth (molting to 66 hr), the second to synthesis for storage or export (M + 66 to M + 156 hr), and the third to preparation for pupation (M + 156 to pupation at M + 192 hr). From M + O to M + 156 and from M + 180 to M + 188 hr, protein is taken up into multivesicular bodies. Larger MVB's form a continuous series with the protein granules formed from M + 162 to M + 180 hr. Blood proteins increase in concentration and amount from M + 66 to M + 156 hr at the same time as the fat body cells have a high rate of incorporation of amino acids and a structure appropriate for protein synthesis. During granule formation, both amino acid incorporation and blood protein concentration decrease. Since foreign proteins injected into the blood appear in the granules, they are probably made mainly from sequestered blood. Protein uptake involves two stages: concentration between the cells, and ingestion in pinocytotic vesicles. The vesicles fuse to become MVB's or storage granules, depending upon their rates of growth and the addition of lytic enzymes. Since MVB's do not accumulate in the fat body and since many of them contain acid phosphatase and appear empty, they are presumed to be concerned in protein turnover.Keywords
This publication has 34 references indexed in Scilit:
- Protein Uptake in Multivesicular Bodies in the Molt-Intermolt Cycle of an InsectScience, 1967
- The in vitro incorporation of [U-14C] valine into fat body protein of the larva of the blowfly, Calliphora erythrocephalaJournal of Insect Physiology, 1966
- A Neural Fat-body Sheath in a Phytophagous Insect (Carausius morosus)Nature, 1966
- THF EARLY STAGES OF ABSORPTION OF INJECTED HORSERADISH PEROXIDASE IN THE PROXIMAL TUBULES OF MOUSE KIDNEY: ULTRASTRUCTURAL CYTOCHEMISTRY BY A NEW TECHNIQUEJournal of Histochemistry & Cytochemistry, 1966
- The structure and formation of the cuticulin layer in the epicuticle of an insect, Calpodes ethlius (Lepidoptera, Hesperiidae)Journal of Morphology, 1966
- Sequestration of Protein by the Fat Body of an InsectNature, 1966
- Functions of LysosomesAnnual Review of Physiology, 1966
- HISTOCHEMICAL STUDIES ON THE UPTAKE OF HORSERADISH PEROXIDASE BY RAT KIDNEY SLICESThe Journal of cell biology, 1965
- PROTEIN UPTAKE IN THE OOCYTES OF THE CECROPIA MOTHThe Journal of cell biology, 1965
- A STUDY OF PHAGOCYTOSIS IN THE AMEBA CHAOS CHAOS The Journal of cell biology, 1965