Date of Award
1987
Degree Type
Dissertation
Degree Name
Doctor of Philosophy
Abstract
Sheets of dorsal abdominal integument, ligated tubes of midgut, sheets of fat body and suspended hemocytes from mid fifth instar larvae of Calpodes ethlius (Lepidoptera: Hesperiidae) were incubated in artificial hemolymph in the presence of ({dollar}\sp{lcub}35{rcub}{dollar}S) methionine to investigate protein synthesis and secretion. Epidermis secretes at least 13 polypeptides basally and 15 apically. Four basally secreted polypeptides were identified in the hemolymph labelled in vivo. Midgut secretes at least eight polypeptides basally and seven apically. Two basally secreted polypeptides were similar to those in the hemolymph. Fat body releases more than 14 polypeptides into the incubation medium and 12 of which are found in the hemolymph. Hemocytes secrete 11 polypeptides and seven of which could be identified in the hemolymph.;Antibodies made against hemolymph proteins recognized five epidermal, eight midgut, ten fat body and six hemocyte secretory polypeptides indicating that these four tissues contribute at least 29 polypeptides to the hemolymph protein pool. Arylphorin (Ar) is the major hemolymph protein secreted by all four tissues. Arylphorin synthesized and secreted in vitro by all four tissues has been identified through its precipitation with antibodies made against hemolymph Ar.;Fifth stage Calpodes larvae have three major hemolymph proteins SP1 (720 K), SP2 (580 K) and Ar (470 K). The 470 K protein is identified as Ar because it is rich in aromatic amino acids. Electron microscopy of negatively stained preparations show that each polymer has a different geometrical arrangement of subunits. SP1 is a cube made from eight subunits. SP2 is a hexamer in the form of a pentahedral prism. Ar is probably an octahedron made from six subunits.;Forty six hemolymph polypeptides are stage specific in addition to ten polypeptides that are present throughout the fourth, fifth stage larval and pupal hemolymph. Each growth phase is characterized by the presence of many minor polypeptides that are either absent at all other times or present during only one other phase. Some of the most abundant polypeptides also change with development. Ar is present from early in the stadium and continues into the pupa. SP1 is synthesized from 66 hr and SP2 appears two days later. Both storage proteins start to disappear at the beginning of pupation and are absent in the pupa.
Recommended Citation
Palli, Subba Reddy, "Hemolymph Proteins: Origin And Developmental Changes In The Last Larval Instar Of Calpodes Ethlius (lepidoptera: Hesperiidae)" (1987). Digitized Theses. 1662.
https://ir.lib.uwo.ca/digitizedtheses/1662